Article 45474 of comp.sys.cbm:
From: rhialto@mbfys.kun.nl (Olaf Seibert)
Newsgroups: comp.sys.cbm
Subject: PetIO.doc   V1.5 14.11.95
Date: 25 Nov 1995 21:36:59 GMT
Organization: University of Nijmegen, The Netherlands
Lines: 2160
Distribution: world
Message-ID: <49829r$oq5@wn1.sci.kun.nl>
NNTP-Posting-Host: severus.mbfys.kun.nl


PetIO.doc   V1.5 14.11.95
=========================

Summarised by Olaf Seibert, from "Programming the PET/CBM" (by Raeto Collin
West) chapter 14, The Transactor, Volume 4 Issue 05, articles posted by
Veit Laule, and other sources.

Now also contains the "8296 addendum".

PIA 6520 and VIA 6522
---------------------

In the PET, you find the two PIAs at E810 and E820, and the VIA at E840.

The PIA
-------
The PIA has two 8-bit I/O ports, A and B, which are mostly identical in
function.  All 8 bits can be set to input (1 in the DDR) or output (0 in
the DDR) independently. Bit 2 in CRx determines whether the DDRx or Px are
accessed.  Each port has 2 control lines: CA1, CA2, CB1, CB2. The Cx1 are
input only, the Cx2 can be input or output.

PIAs have two interrupt lines: IRQA and IRQB. They may go low on a change
on the inputs of the Cxy lines. These interrupts may be enabled on either
an 1->0 or an 0->1 transition. The selected transition is called the
"active" transition. The flags which register that an active transition has
occurred are reset by reading the appropriate PORT register.

Register map:

E810  PORT A or DDR A: Data Direction Register A
E811  CRA: Control Register A
E812  PORT B or DDR B: Data Direction Register B
E813  CRB: Control Register B

Control registers:

CRA:

bit   meaning
---   -------
 7    CA1 active transition flag. 1= 0->1, 0= 1->0
 6    CA2 active transition flag. 1= 0->1, 0= 1->0
 5    CA2 direction	      1 = out	     | 0 = in
 4    CA2 control   Handshake=0 | Manual=1   | Active: High=1 Low=0
 3    CA2 control   On Read=0	| CA2 High=1 | IRQ on=1, IRQ off=0
		    Pulse  =1	| CA2 Low=0  |
 2    Port A control: DDRA = 0, IORA = 1
 1    CA1 control: Active High = 1, Low = 0
 0    CA1 control: IRQ on=1, off = 0

CRB works identical for CB1 and CB2, except for the differences in
handshaking.

The Cx2 handshake is not identical between ports. For port A, the handshake
is on reading the PORT A register, for CB2 the handshake is sent on writing
the PORT B register.

On the listening side:

BIT 3 LOW with CA2: CA2 is now controlled by two events:
    (i) CA1 active transition sets it high ("Data Valid")
    (ii) a READ operation sets it low ("Data Accepted").

On the talking side:

BIT 3 LOW with CB2: CB2 is now controlled by two events:
    (i) CB1 active transition sets it high ("Ready For Data")
    (ii) a WRITE operation sets it low ("Data Valid").

Bit 2 HIGH: Causes pulse output, CA2 or CB2 going low for one cycle only
after a read or write operation. This pulse may be too short for some uses.

For operation with a sending and a receiving PIA one would connect

talker	    listener
------	    --------
Port B	 -> Port A
CB2	 -> CA1 with active = 1->0 (data valid)
CB1	<-  CA2 with active = 1->0 (data accepted and ready for more)

Use of PIA signals in a PET:

PIA 1

E810	PORT A	7   Diagnostic sense (pin 5 on the user port)
		6   IEEE EOI in
		5   Cassette sense #2
		4   Cassette sense #1
		3-0 Keyboard row select (through 4->10 decoder)
E811	CA2	    output to blank the screen (old PETs only)
		    IEEE EOI out
	CA1	    cassette #1 read line
E812	PORT B	7-0 Contents of keyboard row
		    Usually all or all but one bits set.
E813	CB2	    output to cassette #1 motor: 0=on, 1=off
	CB1	    screen retrace detection in. This input is used to
                    generate the 50 or 60 Hz IRQ. Also connected to
		    VIA PB5.

PIA 2

E820	PORT A	    Input buffer for IEEE data lines
E821	CA2	    IEEE NDAC out
	CA1	    IEEE ATN in
E822	PORT B	    Output buffer for IEEE data lines
E823	CB2	    IEEE DAV out
	CB1	    IEEE SRQ in

The VIA
-------
The VIA is a superset of the PIA. Many of the principles apply here as
well, though the organisation is slightly different.

The VIA has two ports, PA and PB, 4 control lines C[AB][12], an 8-bit shift
register SR and 2 timers TA and TB.

Like the PIA, the Cx1 lines are input only, the Cx2 lines are I or O.

Port A has two registers. One register causes handshaking with CA1 to
happen, the other doesn't. Port B occurs in memory before port A.
There are control registers CRA, CRB, ACR, PCR, and interrupt registers IFR
and IER. The data direction registers DDRA and DDRB have their own
addresses, unlike the PIA.

I'll only describe the extra or different features.

Timers. The VIA has two 16-bit timers T1 and T2. When written to the timers
start counting down on each clock cycle, and when reaching 0000 will flag
and may cause an interrupt or other special action. When the low byte of
the timer is read, the interrupt flag is cleared. Writing to the high
byte clears the flag and starts the timer counting.

T1 has a latch register. This is a place to store the timer value before it
will be used. When T1 reaches 0, the latch value is moved into the timer so
that the countdown may begin all over again, if so enabled.

Ports. PA and PB may be latched, so that on an active transition of CA1 the
value in the PA register is retained indefinitely (or until the next active
transition on that pin), and similarly with CB1 and PB.

The shift register. This 8-bit register is connected to CB2. On command the
SR performs 8 shifts, moving 8 bits to or from CB2 one at a time. The most
significant bit is moved first (the register shifts left). The SR can be
timed by T2 and at the same rate as the 6202, using the phase 2 clock phi2.
Alternatively an external clock may time it.

It seems there are bugs in the shift register. For instance, when doing
cassette I/O, the CB2 sound, which uses the SR, must be turned off.
Also (on my machine), when generating sound one must first set the shift
register in "free running" mode, and then load it with a value to shift.
The other way around does not seem to work.

The ACR controls the timers, shift register and latch status of PA and PB.
(T1 has effects on pin PB7, which are not described in the book, but I
suspect they are similar to the features of the CIA in this respect. -Olaf)

ACR E84B

7-6 Timer 1 control
    0 = PB7 unused
    0 0 = one shot
    0 1 = continuous, i.e. on underflow timer restarts at latch value.
    (The following 3 lines are guessed, based on the Amiga's CIA description)
    1 = PB7 used
    1 0 = T1 underflow toggles PB7
    1 1 = T1 underflow pulses PB7
5   Timer 2 control
    0 = one shot
    1 = count set no. of PB6 pulses
4-2 Shift register control
    000 = shift reg disabled
    001 = shift in by timer 2
    010 = shift in by phi2
    011 = shift in by external clock (PB6?)
    100 = free run by timer 2 (setting for sound)
	  this means keep shifting the same byte out over and over.
	  T2 is hereby set to continuous mode.
    101 = shift out by timer 2
    110 = shift out by phi2
    111 = shift out by external clock (PB6?)
1   Port B latch
    0 = disabled
    1 = enabled on CB1 transition (in/out)
0   Port A latch
    0 = disabled
    1 = enabled on CA1 transition (in)

The Periheral Control Register PCR  controls the operating modes of the
control lines CA1-CB2.

PCR E84C

7-5 CB2 control
 7  direction
    1 = output
    1 0 = do handshake
    1 0 0 = on write
    1 0 1 = pulse?
    1 1 = manual CB2 control
    1 1 0 = CB1 low
    1 1 1 = CB1 high
    0 = input
    0 0 x = Active low:  1->0
    0 1 x = Active high: 0->1
    0 x 0 = Clear Interrupt condition on write of 1 in IFR or r/w of ORB
    0 x 1 = Clear Interrupt condition on write of 1 in IFR only
4   CB1 control
    0 = active transition low
    1 = active transition high
3-1 CA2 control (similar to CB2 control)
 3  direction
    1 = output
    1 0 = do handshake
    1 0 0 = on read
    1 0 1 = pulse
    1 1 = manual CA2 control
    1 1 0 = CA1 low
    1 1 1 = CA1 high
    0 = input
    0 0 x = Active low:  1->0
    0 1 x = Active high: 0->1
    0 x 0 = Clear Interrupt condition on write of 1 in IFR or r/w of ORB
    0 x 1 = Clear Interrupt condition on write of 1 in IFR only
0   CA1 control
    0 = active transition low
    1 = active transition high

The handshaking is not specifically described in the book, so I presume it
is identical to that of the PIA.

The interrupt conditions for the control lines can be cleared by writing a
1 bit in the corresponding bit in the IFR. Optionally for CA2 and CB2 it
can also be cleared by accessing the port data register.

Interrupt Flag Register IFR and Interrupt Enable Register IER. These
registers are symmetrical wrt each other. The IER enables specific
interrupts (i.e., allows an event to trigger an interrupt), and the IFR
flags if the event took place.

When writing to the IER bit 7 controls the meaning of the 1 bits in the
data: when set each 1-bit sets the interrupt enable bit, when cleared it
resets that interrupt enable bit.

The flags in IFR can be cleared by writing a 1 in them (and bit 7 clear).

IFR E84D
IER E84E

7   IFR: master flag bit: 1 when any of the other bits are set
    IER: 0 disables, 1 enables interrupts
6   Timer 1 underflow
5   Timer 2 underflow
4   CB1 active transition
3   CB2 active transition
2   Shift register full/empty
1   CA1 active transition
0   CA2 active transition

Use of VIA signals in a PET
---------------------------
E840	PORT B	7   DAV in
		6   NRFD in
		5   screen retrace in (also connected to PIA1 CB1)
		4   cassette #2 motor (note 2)
		3   cassette write data out
		2   ATN out
		1   NRFD out
		0   NDAC in
E841	PORT A	    USER PORT with CA2 handshake (note 1)
E842	DDRB	7-0 normal bits set to 0 0 0 1 1 1 1 0
E843	DDRA	7-0 USER PORT data direction register
E844	Timer 1 LO
E845	Timer 1 HI  (set to $FF on system power-on)
E846	Timer 1 latch LO
E847	Timer 1 latch HI
E848	Timer 2 LO
E849	Timer 2 HI
E84A	Shift register
E84B	ACR	Aux. control register; set to $00 at power on
		7-6 timer 1 control
		5   timer 2 control
		4-2 shift register control
		1   port B latch
		0   port A latch
E84C	PCR	Peripheral Control Register; set to $0C or $0E at power on
		7-5 CB2 control (user port pin M) (note 3)
		4   CB1 control (note 3)
		3-1 CA2 control (graphics mode) (note 3)
		0   CA1 control (note 3)
E84D	IFR	Intertrupt Flag Register; set to $00 at power on
		7   IRQ on/off
		6   T1 interrupt flagged
		5   T2 interrupt flagged
		4   CB1 interrupt flagged
		3   CB2 interrupt flagged
		2   shift register interrupt flagged
		1   CA1 interrupt flagged
		0   CA2 interrupt flagged
E84E	IER	Interrupt Enable Register; set to $80 at power on
		7   1=enable, 0=disable
		6-0 enable interrupts; same bits as in IFR.
E84F	PORTA	    USER PORT without CA2 handshake

Note 1: E84F is the preferred user port register, since CA2 controls screen
graphics.

Note 2: The motor is on when this line is low, and off when it is high.

Note 3: CA1 is connected to pin B of the user port. Pins B-L correspond to
port A, which is invariably E84E. CB2 (connected to the shift register) also
connects to pin M of the user port; square wave tones (see chapter 9 of
"Programming the PET/CBM") use these facts. CB1 signals input from cassette
#2. CA2 controls screen graphics: it is configured for output, and, when
low, gives lower case characters and others. When high, the mode is upper
case and graphics.

VIA use by BASIC and KERNEL
---------------------------
T1 and T2 are used (though the T1 latch is ignored). T2 is only used for
cassette operations, to time reading and writing of bits. T1 is used to
time out the IEEE-488 bus response (before setting ST) and also with
cassette (although not to such an extent as T2). Both timers also
contribute to RND(0), but Basic 1 uses the wrong addresses for this. T1 is
also used in Basics < 4 to time the screen-scroll delay when RVS or the
left-arrow key is pressed.

Interrupts from T1 and T2 are used for cassette and IEEE handling. CB1
interrupts are also used with cassette. The kernel does not use interrupts
from CB2, SR, CA2 and CA2.

CB2 and the shift register are used for the bell sound, which exists only
in Basic 4.


64 K RAM expansion in 8096 and 8296
-----------------------------------
From: UKAH@ibm3090.rz.uni-karlsruhe.de (Veit Laule)
Newsgroups: comp.sys.cbm
Date: Tue, 22 Nov 1994 16:38
Organization: University of Karlsruhe, Germany
Message-ID: <19941122163828UKAH@ibm3090.rz.uni-karlsruhe.de>

8096 exp-mem (64K):
The control register is at $FFF0/65520
You have 4 16K-banks, 0...3

$8000	  $9000 	      $C000	      $E800    $F000	 $FFFF
!----------------------------!!--------------------------------------!
	Bank 0 or 2			Bank 1 or 3
!--------!				      !-------!
  screen					io

Control Register $FFF0:
bit 7:	0 normal 8032 configuration (screen, ROMs, IO, ROMs)
       80 expansion memory
bit 6:	0 RAM $E800-$EFFF (only when bit7=1)
       40 IO peek through
bit 5:	0 exp-mem $8000-$8FFF (-"-)
       20 screen peek through
bit 4: 10 not used
bit 3:	0 bank 1 $C000-$FFFF
       08 bank 3
bit 2:	0 bank 0 $8000-$BFFF
       04 bank 2
bit 1: 02 write protect bank 1/3
bit 0: 01 write protect bank 0/2
when bit7=0, all other bits are ignored

The missing 32K can't be accessed witout hardware modifications.
You can only use the 2K "behind" the screen $8800-$8FFF (exact: 34768-
36863), available in the normal configuration.
The register is write-only, and the value is written through to the
previously selected ram bank.

6545/6845 CRT	(6545 used in CBM 8xxx + FAT FOURTY,
-------------	 6845 used in CBM 6/7x0 (B-series))
This info taken from Transactor Volume 4, Issue 05 and an article by
Veit Laule. Note that the Transactor lists the 6545 with the B series info.
Date: Wed, 14 Dec 1994 17:41
Message-ID: <19941214174145UKAH@ibm3090.rz.uni-karlsruhe.de>

This chip is only available with the wide-screen (12 inch) models.
40 column models clock this chip at 1MHz, 80 column models at 2 MHz.

E880: register select
E881: register contents

Reg#	Meaning
---------------
 R0	Horizontal total number of characters on line (Nht) including
	horizontal retrace (true value = number + 1)
 R1	Horizontal total number of characters displayed (Nhd)
 R2	Distance (in characters) from left to right margin of screen + 1
 R3	Sync width. Low nibble is vertical sync width (in lines) (0=16).
		    High nibble is horizontal sync (in characters).
 R4	Number of display lines including retrace (Nvt) (7 bits)
 R5	Vertical position of the edge of the screen (5 bits)
 R6	Number of display lines on screen (Nvd) (7 bits)
 R7	Height of upper edge from bottom of screen (in lines displayed)
	(7 bits)
 R8	different between 6545 and 6845, not used
	6545: Interlace and Skew:
	  Bit 0: 1=interlace mode, 0=non interlaced mode
	  Bit 1: if bit 0 = 1then interlace and video mode
	  Bit 2: not used (not true?).
	  Bit 3: not used.
	  Bit 4: 1=scan from 32770 (8002) in memory
	  Bit 5: 1=scan from 32772 (8004) in memory
	  Bit 6: cursor (not implemented on the PET)
	  Bit 7: cursor (not implemented on the PET)
 R9	Number of lines between top of one display line and the next (-1)
	(5 bits)
R10	Cursor (not implemented on the PET)
	cursor start line, bits 4-0
	bit 6	bit 5	Cursor Operating Mode
	-------------------------------------
	  0	  0	display cursor continuously
	  0	  1	blank cursor
	  1	  0	blink cursor at 1/16 field rate
	  1	  1	blink cursor at 1/32 field rate
R11	Cursor end line (5 bits)  (not implemented on the PET)
R12	Control register:
	  Bit 0: 1=add 256 to screen start address ( 512 for 80-columns)
	  Bit 1: 1=add 512 to screen start address (1024 for 80-columns)
	  Bit 2: invert flyback
	  Bit 3: invert video signal
	  Bit 4: use top half of 4K character generator
	  Bit 5: (not implemented on the PET)
	  Bit 6: (not implemented on the PET)
	  Bit 7: not used.
	Note: In my 8296 I could not confirm bits 2-7.
R13	Value + 32786 (8000) is address of first character
	(multiply by 2 for 80-column models)
R14	Cursor location HI (not implemented on the PET)
R15	Cursor location LO (not implemented on the PET)
R16	Light pen position HI (read only)
R17	Light pen position LO (read only)
R18	Update address high, 6bit (only 6545)
R19		       low	    -"-

R0-R13, R18, R19 are writeonly
R16, R17	 are readonly

R16-R19 are not used
R10, R11, R14, R15 are only used in the CBM 6/700 (hardware cursor)


RIOT 6532
---------
Source: TOuCHE manual: the keyboard for the Apple-II clone from
the Computer Hobbyvereniging Eindhoven. (They got DDRA and DDRB reversed.)

The RIOT is used at least in the diskdrives of type 2040, 3040, 4040, 8050,
8250. They contain two RIOTs (at $0200 and $0280) and a VIA (at $????).

The RIOT (RAM, I/O and Timer) has 128 bytes of RAM, 2 8-bit bidirectional
I/O ports, and a timer that can count down at 4 different rates.

Reg.	Name	Description
---------------------------
 0	PA	Port A data
 1	DDRA	Port A Data Direction Register
 2	PB	Port B data
 3	DDRB	Port B Data Direction Register
 4	Timer	Timer read register
14,0E	T1	1 clocks per decrement
15,0F	T8	8
16,10	T64	64
17,11	T1024	1024

The Data and DDR registers are as usual. The input is a buffer, the output
is a latch.

The Timer register reads out the timer value; its initial value is set by
writing into the T1..T1024 registers. Which one is used determines the
number of clock cycles between decrements of the Timer register.

The chip also has an IRQ line but the cited source does not say anything
further about it. The 8050 fdc rom usage suggests an irq is generated on
timer underflow, with no special setup required.

Pinout:

 1  0V				    21	PB3
 2  A5	Address lines		    22	PB2
 3  A4	(see also pin 40)	    23	PB1
 4  A3				    24	PB0
 5  A2				    25	IRQn
 6  A1				    26	D7	Data bus lines
 7  A0				    27	D6
 8  PA0 Port A data		    28	D5
 9  PA1 			    29	D4
10  PA2 			    30	D3
11  PA3 			    31	D2
12  PA4 			    32	D1
13  PA5 			    33	D0
14  PA6 			    34	RESn	Reset
15  PA7 			    35	R/Wn
16  PB7 Port B data		    36	RSn	RAM Select
17  PB6 			    37	CSn
18  PB5 			    38	CS	Circuit Select
19  PB4 			    39	PHI2	Clock
20  +5V 			    40	A6	Address line



IEEE Port Pinouts
-----------------
This info taken from Transactor Volume 4, Issue 05.

rear view for IEEE and User port:

	   1   2   3   4   5   6   7   8   9   10  11  12
	  --- --- --- --- --- --- --- --- --- --- --- ---
	===================================================
	  --- --- --- --- --- --- --- --- --- --- --- ---
	   A   B   C   D   E   F   H   J   K   L   M   N

Contact spacing: 3.96 mm from centre to centre.

The User port is the second port from the left, the IEEE-488 port is
the third port. The left port is a cassette port, but cassette #1 and #2
have moved around in various models. The other port is either inside the
case for older models or at the right-hand side for newer models.

Some machines (at least the 8032 SK) has a proper IEEE-488 connector for
the IEEE-488 port instead of the more common card edge connector.  Those
machines also have such a connector for the user port but mounted
upside-down.

PET   IEEE
Pin#  Pin# Mnemonic Definition
-----------------------------------
 1     1   DIO1     Data Input/Output Line #1         (PIA2 PA in, PIA2 PB out)
 2     2   DIO2     Data Input/Output Line #2
 3     3   DIO3     Data Input/Output Line #3
 4     4   DIO4     Data Input/Output Line #4
 5     5   EOI	    End Or Identify                 (PIA1 PA6 in, PIA1 CA2 out)
 6     6   DAV	    Data Valid                       (VIA PB7 in, PIA2 CB2 out)
 7     7   NRFD     Not Ready For Data                (VIA PB6 in, VIA PB1 out)
 8     8   NDAC     Not Data Accepted                (VIA PB1 in, PIA2 CA2 out)
 9     9   IFC	    Interface Clear
10    10   SRQ	    Service Request                          (PIA2 CB1 in only)
11    11   ATN	    Attention                           (VIA PB2 out, PIA2 CB1)
12    12   GND	    Chassis Ground (IEEE cable shield)
 A    13   DIO5     Data Input/Output Line #5         (PIA2 PA in, PIA2 PB out)
 B    14   DIO6     Data Input/Output Line #6
 C    15   DIO7     Data Input/Output Line #7
 D    16   DIO8     Data Input/Output Line #8
 E    17   REN	    Remote Enable
 F    18   GND	    DAV Ground
 H    19   GND	    NRFD Ground
 J    20   GND	    NDAC Ground
 K    21   GND	    IFC Ground
 L    22   GND	    SRQ Ground
 M    23   GND	    ATN Ground
 N    24   GND	    Data Ground (DIO1-8)

User port
---------

Pin# Function Description
-------------------------
 1   Ground   System Ground
 2   TV Video Video Out for external displays
 3   SRQ      Connected to IEEE-488 SRQ (PIA2 CB1 in only)
 4   EOI      Connected to IEEE-488 EOI (PIA1 PA6 in, PIA1 CA2 out)
 5   Diagnostic Sense (PIA1 PA7)
	      Held low causes power up to diagnostic routines or monitor
 6   Read 1   Connected to cassette #1 read line (PIA1 CA1)
 7   Read 2   Connected to cassette #2 read line (VIA CB1)
 8   Write    Diagnostic cassette write verify (VIA PA3)
 9   Vert     TV Vertical for external displays
10   Horiz    TV Horizontal for external displays
11   GND
12   GND
 A   GND
 B   CA1      Edge sensitive input for 6522 VIA
 C   PB0      PB0-7 are independently programmable
 D   PB1      for Input or Output
 E   PB2
 F   PB3
 H   PB4
 J   PB5
 K   PB6
 L   PB7
 M   CB2      Special IO pin of VIA, connected to shift register
 N   GND      Digital ground

Cassette port
-------------
	   1   2   3   4   5   6
	  --- --- --- --- --- ---
	==========================
	  --- --- --- --- --- ---
	   A   B   C   D   E   F

Contact spacing: 3.96 mm from centre to centre.

Pin# Name  Description
----------------------
A-1  GND   Digital Ground
B-2  +5V   +5 Volts to operate cassette circuitry only
C-3  Motor Computer controlled +6V for cassette motor
D-4  Read  Read line from cassette
E-5  Write Write line to cassette
F-6  Sense Monitors closure of any locking type cassette switch

Keyboard matrix
===============

There are two different keyboards: the graphics keyboard and the
business keyboard.

After analysis of the 50 and 60 Hz versions of the 8032 business
roms, there are apparently even difference between the keyboards of
those versions. The 60 Hz values are listed below the 50 Hz ones,
if they differ.

In Basic 4.0 CRTC the (PETSCII) values listed in the table below are
recorded in location 151 [this makes distinguishing between the normal 0
key and the one on the numeric keypad impossible]; in older versions (and
4.0 without CRTC) the position in the table is recorded. The position is
8 * (9 - row) + (7 - column) + 1, i.e. starting at 1, incrementing left to
right and top to bottom.

The keyboard is scanned by writing the row number into the row select port
($E810), then reading the column bits ($E812). Each bit that reads 0
represents a pressed key.

; 00 = Shift
; 10 = Repeat
; 80   flags unshiftable key
; FF = No key

Business keyboard decoding table:

----+------------------------
row |  7  6  5  4  3  2  1  0
----+------------------------
 9  | 16 04 3A 03 39 36 33 DF
    | ^V --  : ^C  9  6  3 <-	^V = TAB + <- + DEL, ^C = STOP,
    |				 <- = left arrow
 8  | B1 2F 15 13 4D 20 58 12
    | k1  / ^U ^S  m sp  x ^R	k9 = keypad 9, ^U = RVS + A + L,
    |				^S = HOME, sp = space, ^R = RVS
 7  | B2 10 0F B0 2C 4E 56 5A	^O = Z + A + L, rp = repeat
    | k2 rp ^O k0  ,  n  v  z
    |
 6  | B3 00 19 AE 2E 42 43 00
    | k3 rs ^Y k.  .  b  c ls	^Y = left shift + TAB + I, k. = keypad .
    |				ls = left shift, rs = right shift
 5  | B4 DB 4F 11 55 54 45 51	^Q = cursor down
    | k4  [  o ^Q  u  t  e  q
    |    5D]
 4  | 14 50 49 DC 59 52 57 09
    | ^T  p  i  \  y  r  w ^I	^T = DEL, ^I = TAB
    |          C0@
 3  | B6 C0 4C 0D 4A 47 44 41
    | k6  @  l ^M  j  g  d  a	^M = return
    |    5B[
 2  | B5 3B 4B DD 48 46 53 9B
    | k5  ;  k  ]  h  f  s ^[	^[ = ESC
    |    5C\   3B;
 1  | B9 06 DE B7 B0 37 34 31
    | k9 --  ^ k7  0  7  4  1
    |
 0  | 05 0E 1D B8 2D 38 35 32
    |  . ^N ^] k8  -  8  5  2	^N = both shifts + 2, ^] = cursor right
----+------------------------

Graphics keyboard decoding table:

----+------------------------
row |  7  6  5  4  3  2  1  0
----+------------------------
 9  | 3D 2E FF 03 3C 20 5B 12
    |  =  . -- ^C  < sp  [ ^S	^C = STOP, ^S = HOME
    |
 8  | 2D 30 00 3E FF 5D 40 00
    |  -  0 rs  > --  ] @  ls	rs = right shift, ls = left shift
    |
 7  | 2B 32 FF 3F 2C 4E 56 58
    |  +  2 --  ?  ,  n  v  x
    |
 6  | 33 31 0D 3B 4D 42 43 5A
    |  3  1 ^M  ;  m  b  c  z	^M = return
    |
 5  | 2A 35 FF 3A 4B 48 46 53
    |  *  5 --  :  k  h  f  s
    |
 4  | 36 34 FF 4C 4A 47 44 41
    |  6  4 --  l  j  g  d  a
    |
 3  | 2F 38 FF 50 49 59 52 57
    |  /  8 --  p  i  y  r  w
    |
 2  | 39 37 5E 4F 55 54 45 51
    |  9  7  ^  o  u  t  e  q
    |
 1  | 14 11 FF 29 5C 27 24 22
    | ^T ^Q --  )  \  '  $  "	^T = DEL, ^Q = cursor down
    |
 0  | 1d 13 5F 28 26 25 23 21
    | ^] ^S <-  (  &  %  #  !	^] = cursor right, ^S = home
----+------------------------

The original gfx keyboard reflects the matrix perfectly:

	  !  "  #  $  %  '  &  \  (  )  <-     ^s ^q ^] ^t
	  q  w  e  r  t  y  u  i  o  p  ^       7  8  9  /
	  a  s  d  f  g  h  j  k  l  : ^m       4  5  6  *
	  z  x  c  v  b  n  m  ,  ;  ? ^m       1  2  3  +
	 LS ^r  @  [  ]  SPACE <  > ^c  RS      0  .  -  =

The shift key always set the high bit, producing a graphic character.


CONTROL CODES
=============

F: only on 4.0 fat-40, i.e. NOT on upgrade 4.0 roms.
8: only on 4.0 80 columns.
4B: only on 4.0 upgrade, B keyboard (maybe also on N keybd but I don't
    have a ROM to verify this)

+------+------------------------------+------------------------------------+
|ctrl- | unshifted                    | shifted (unshifted + 128)          |
+------+------------------------------+------------------------------------+
| C  3 | stop                         | load/run, dload"*/run, or dL"*/run |
| G  7 | bell                         | double bell                        |
| I  9 | tab (4B,F,8)                 | set/clear tab (4B,F,8)             |
| M 13 | return                       | fake return                        |
| N 14 | text mode (F,8)              | graphics mode (F,8)                |
| O 15 | set top of window (8)        | set bottom of window (8)           |
| P 16 | erase end of line (F)        | see note (no function)             |
| Q 17 | cursor down                  | cursor up                          |
| R 18 | reverse field on             | reverse field off                  |
| S 19 | cursor home                  | clear screen                       |
| T 20 | delete char left of cursor   | insert space at cursor             |
| U 21 | delete line (8)              | insert line (8)                    |
| V 22 | erase end of line (8)        | erase begin of line (F,8)          |
| Y 25 | scroll up (8)                | scroll down (8)                    |
| [ 26 | escape: end inst & quote mode| (no function)                      |
| ] 28 | cursor right                 | cursor left                        |
|      |                              | 255 pi (converted to 94)           |
+------+------------------------------+------------------------------------+

Note: on the 4.0-40-crtc version the code for "erase end of line" is
different from the 4.0-80 code. Note that the decimal notation of the
former (16, or $10) equals the hex notation of the latter ($16, or 22).
This suggests a typo while editing the assembly source for the other
version.


CBM 8296
========

What follows was typed in by yours truely from a photocopy of an
"original". I hope I have reproduced the contents faithfully, even
though this is a bit hard with some tables. Most text is in typewriter
font, right-aligned, but some is in a proportional font and I had to
rearrange some of that text.

I left the small indications of German origin.

Text between [square brackets] is mine.

-Olaf

CBM 8296

SUPPLEMENT to the 8032 Manual					Seite

1.	Introduction						1

2.	Memory system						1
2.1	Memory mapping						1
2.2	Control register					3
2.3	Modification of memory system				4
2.4	User Jumper						5

3.	Video-RAM						6

4.	Hardware expansion via J4, J9				7
4.1	Memory expansion bus J4, J9				7
4.2	Power supply for hardware expansion			7

5.	Programming the expansion memory bank			8
5.1	I/O handling						8
5.2	Interrupt processing					9
5.3	Interrupt Handler Program				9

Annex

A	Memory map						12

B.1	Connectors 8296						13
B.2	Connectors, modification as compared with 8032		17

C	Software addendum					18


1.	Introduction

The CBM 8296 is an expanded version of the CBM 8032, and is fully
software compatible with the CBM 8096. Where the hardware is con-
cerned, there are some amendments and additional options, since
the CBM 8296 has a total of 128 k RAM. The plug arrangements are
also slightly different.



2.	Memory system

The CBM 8296 has two RAM banks, each with 64 k bytes, designated
here the main memory and the expansion memory.

The main memory is activated on switch-on, and the computer reacts
like a standard CBM 8032.


2.1	Memory Mapping

Expansion memory can be mapped into main memory addresses $8000
through $FFFF. See Figure 2-1. Only two of the 16k expansion
blocks can reside in main memory at one time. This provides an
additional 32k bytes of memory to the user.

Selection of the expansion blocks is by bits 2 and 3 of the
expansion memory control register. Each 16k block has a 16k
alternate that can be selected by bits 2 and 3 of the control
register.

Main memory addresses $8000 through $BFFF can only be mapped by
expansion blocks 0 or 1.  Main memory addresses $C000 through $FFFF
can only be mapped by expansion blocks 2 or 3.


				- 1 -



0	+----------------+ 0000
	|                |
	|                |
	|                |
	|                |
	|                |
	|                |
	|                |
	|                |
16K	+----------------+ 4000
	|                |
	|                |
	|                |
	|                |
	|                |
	|                |
	|                |
	|                |
32K	+----------------+ 8000 ............. +--------------+ +--------------+
	|     Screen     |                    |              | |              |
	+----------------+ 9000               |              | |              |
	|                |	ADDRESSES     | BLOCK 0      | | BLOCK 1      |
	|                |	8000 TO BFFF  | 16K          | | 16K          |
	|                |	(32K TO 48K)  |              | |              |
	|                |                    |              | |              |
	|                | BFFF               |              | |              |
48K	+----------------+ C000 ............. +--------------+ +--------------+
	|                |                    |              | |              |
	+----------------+	  	      |              | |              |
	|                |      ADDRESSES     | BLOCK 2      | | BLOCK 3      |
58K	+----------------+      C000 TO FFFF  | 16K          | | 16K          |
	|                | E800 (48K TO 64K)  |              | |              |
60K	|......I/O.......| F000               |              | |              |
	|                | FFFF               |              | |              |
64K	+----------------+                    +--------------+ +--------------+



		Figure 2-1.  Expansion memory mapping


				- 2 -


2.2	Control Register

Control of the expansion memory is through a memory control
register located at address $FFF0. The memory control
register provides selection of 16k-byte blocks, write
protection, enabling the expansion memory, I/O peek through
and screen peek through. Because the memory control register
is write only, a copy of the register should be kept in the
lower 32k of main memory.

Figure 2-2 depicts the functions of the memory control register.
The paragraphs following it describe these functions in detail.

		Address $FFF0
	---------------------------------------------------
	 7      6      5      4      3      2      1      0
	---------------------------------------------------
         |      |      |      |                    |      |
         |      |      |      |                    |      |
Enable --+      |      |      |                    |      +-- Write Protect
                |      |      |                    |          $8000 - $BFFF
		|      |      |                    |
I/O peek through+      |      |      Select        +--------- Write Protect
$E800-$EFFF            |      |       16K                     $C000 - $FFFF
                       |      |      Block:  0 0:  2 and 0
Screen peek through ---+      |              0 1:  2 and 1
$8000-$8FFF                   |              1 0:  3 and 0
                              |              1 1:  3 and 1
Reserved ---------------------+


	Figure 2-2.
	Expansion Memory
	Control Register

Control Register Bit 7 - When equal to 1, enables the expansion memory.
When bit 7 equal to 0, expansion memory is disabled. Bit 7 defaults to 0
on power up.

Control Register Bit 6 - When equal to 1, I/O peek through is enabled.

Control Register Bit 5 - When equal to 1, screen peek through is enabled.

Control Register Bit 4 - Reserved.

Control Register Bit 3 - When equal to 1, block 3 (16k-byte) is selected.
When equal to 0, block 2 (16k-byte) is selected.

Control Register Bit 2 - When equal to 1, block 1 (16k-byte) is selected.
When equal to 0, block 0 (16k-byte) is selected.

Control Register Bit 1 - When equal to 1, addresses $C000 through $FFFF
on the /Expansion Memory Board only/ are write protected.
I/O is not write protected if I/O peek through is enabled.
When equal to 0, the addresses are not write protected.

Control Register Bit 0 - When equal to 1, addresses $8000 through $BFFF
on the /Expansion Memory Board only/ are write protected.
The screen is not write protected if screen peek through is enabled.
When equal to 0, the addresses are not write protected.

				- 3 -


2.3.	Modifications to the main memory system

By contrast with the CBM 8032, each address in the 64 k main
memory is covered by RAM. A write command into any address (apart
from I/O) causes the corresponding RAM address to be written at,
and a read command reads from RAM between $0000 and $8FFF; above
$9000 from the empty [EP]ROM sockets, from the ROM or from the I/O
devices.

RAM			$0000 - $FFFF
Empty socket		$9000 - $AFFF
ROM			$B000 - $FFFF. except $E8XX
I/O			$E800 - $E8FF

The memory system for CPU read accesses can be modified by means of
the signals /RAM SEL 9, /RAM SEL A, and /RAM ON (J4, Pins 12, 13, 14)
in accordance with the following table:


[The first line represents the normal config.  In my machine I have
jumpered J4 (the expansion bus) pins 12 and 13 to ground which gives me
8K of additional RAM which is not cleared on reset. Ground pins are
available in the adjecent row.]

[/NO ROM = 1; see page 12 for more cases]
+-----+--------+------------+-------------------------------------------------+
|     |Control |            |                                                 |
|     |Register|            |      main memory $8000 - $FFFF        [UB1-UB8] |
|     |        |            |      [$0000 - $7FFF is always RAM from UB1-UB8] |
|     |$FFF0   |            |                                                 |
+-----+--------+------------+-------------------------------------------------+
|     |    I/O |___ ___ ___ |              E000                               |
| ___ |    peek|RAM RAM RAM | E800  F000  -E7FF  B000  A000  9000  8000       |
| NO_ |    thr.|___ ___ ___ |              E900                               |
| ROM |CR7 CR6 |ON  S.9 S.A |-E8FF -FFFF  -EFFF -DFFF -AFFF -9FFF -8FFF       |
+-----+--------+------------+-------------------------------------------------+
|     |        |            |                                                 |
|  1  | 0   X  | 1   1   1  | I/O  Kernal Editor BASIC EPROM EPROM SCREEN     |
|     |        |            |                                                 |
|  1  | 0   X  | 1   1   0  | I/O  Kernal Editor BASIC  RAM  EPROM SCREEN     |
|     |        |            |                               +-----+           |
|  1  | 0   X  | 1   0   1  | I/O  Kernal Editor BASIC EPROM  RAM  SCREEN     |
|     |        |            |                         +-----+                 |
|  1  | 0   X  | 1   0   0  | I/O  Kernal Editor BASIC  RAM   RAM  SCREEN     |
|     |        |            |                   +-----+                       |
|  1  | 0   X  | 0   1   1  | I/O  Kernal Editor  RAM   RAM   RAM  SCREEN     |
|     |        |            |            +------+                             |
|  1  | 0   X  | 0   0   1  | I/O  Kernal  RAM    RAM   RAM   RAM  SCREEN     |
|     |        |            |     +------+                                    |
|  1  | 0   1  | 0   X   0  | I/O   RAM    RAM    RAM   RAM   RAM  SCREEN     |
|     |        |            |+----+                                           |
|  1  | 0   0  | 0   X   0  | RAM   RAM    RAM    RAM   RAM   RAM  SCREEN     |
|     |        |            |                                                 |
+-----+--------+------------+-------------------------------------------------+
SCREEN: 2000 bytes for screen memory, and 2096 bytes of available RAM.



  				- 4 -


2.4.	User Jumper

These three signals can be either fixed or programmable via
user jumpers. Bits 0, 1 and 2 are used for control under program
control.

[In my machine these jumpers are not true jumpers.  You must solder two
very tiny locations on the motherboard together to close the jumpers.
Also these locations are rather far apart in the midst of various other
tiny traces. I opted to use J4 instead which has JU1 and JU2 effectively
accessible.]

Jumper      Description of function

            _________
 JU1        RAM SEL A = LOW
            _________
 JU2        RAM SEL 9 = LOW
            _________
 JU3        RAM SEL A to Port A0
            _________
 JU4        RAM SEL 9 to Port A1
            ______
 JU5        RAM ON    to Port A2


To use the user jumpers JU3 to JU5, Pins 0, 1 and 2 of the user
port must be programmed to output.

DR = 59459 ($E843)
DA = 59471 ($E84F)

POKE DR, PEEK (DR) OR 7

The desired combination of bits (0 ... 7) can then be poked into
the port register DA.

N.B. When using JU3, JU4 and JU5, make sure that the user port is
     not written at accidentally. This can happen for instance in
     a number of text processing programs, which emulate a
     Centronics interface via the user port.

                ______
     The signal RAM ON must be high at the start, as it is not
     otherwise possible to complete the POWER ON routine in the ROM.

				- 5 -


3.	Video RAM

As previously, the video RAM is at $8000 - $87CF. With the CBM
8296 however, the CRT controller has access to the full range of
addresses from $8000 - $9FFF. This produces 3 further screen
pages, which can be used for program menues, help lists and the
like. The four screen pages can be written at any time. The
operating system uses the first page only.

Page turning on display is achieved by altering the VIDEO RAM
start address in the CRT controller (reg. 12):

	POKE 59520, 12
	POKE 59521,  x

wherein x=0  for page 1 ($8000-$87CF, switch on figure)
	x=4  for page 2 ($8800-$8FCF)
	x=8  for page 3 ($9000-$97CF)
	x=12 for page 4 ($9800-$9FCF)

Activating the switchover text-modus and graphic-modus brings the
screen page 1 back each time to display.

To use pages 3 and 4, the IC socket UE10 [$9XXX] must be free, or the
/RAM SEL 9 signal set at LOW. Otherwise the ROM in the UE10 trans-
mits data at the same time.

For CPU read access to screen pages 3 and 4, /RAM SEL 9 must again
be set at LOW (see 2.).

Other parameters of the screen controller should be modified by
comparison with the standard operating conditions (text or
graphic) only with extreme caution. The dynamic RAM memories used
require a cyclical refresh, which is produced by the CRT
controller. To be sure of the refresh, the CRT controller must
give at least 256 symbols in an interval of 4 ms.

				- 6 -


4.	Hardware expansions via J4, J9

4.1.	Memory expansion bus J4, J9

Hardware expansions can be linked via the memory expansion bus
(J4, J9).

The data buffer for the expansion bus is, as with the CBM 8032,
always switched in as an output. If the CPU is to read from the
expansion bus, close user jumper JU6 for the range $A000 to $AFFF,
and user jumper JU7 for the range $9000 to $9FFF. The ROM sockets
UE10 or UE9 must of course than remain free. The expansion bus
cannot be read in the range $8000 to $8FFF.

[ There are also JU8 (connected through a resistor) and JU9... ]

A further way of gaining access to the expansion bus is provided
by the line /SEL EXP (J4, Pin 15). Low-level on this line switches
the data bus buffer of the expansion bus to input on a read
command, independently of the address on the CPU. Care should
therefore be taken to avoid bus conflicts when using SEL EXP. Make
sure that only one data source (RAM, ROM I/O or expansion bus) is
activated.
                 _______
The control like SEL EXP must be switched with a collector gate.
Jumpers JU6 and JU7 may also be closed.
       _________    _________
If the RAM SEL 9 or RAM SEL A line is activated, the RAM is
switched in to this address range, and the expansion bus is
switched out.

4.2.	Power supply for hardware expansions.

Connectors J10 and J11 are available for this purpose. As
previously, ground and +9V DC unregulated are available at J11
(0.8 A max.). J10 is modified as compared with the CBM 8032, and
now connected to 8V AC (1 A max.) and ground. Not more than 1A may
be taken out via J10 and J11.

				- 7 -


5.	Programming the expansion memory bank

The user may choose to write his own programs to operate the
expansion memory. A sample program is included in this chapter.





5.1	I/O Handling

I/O in the CBM 8032 consists of the following five devices:

    1. A 6520 PIA at $E810
    2. A 6520 PIA at $E820
    3. A 6522 VIA at $E840
    4. A CRT controller at $E880
    5. Screen memory at $8000 through $87FF

These five I/O devices may be accessed in two ways. The first way is to
simply switch out the expansion memory and restore main memory. This
may be already accomplished by the memory manager software when a CBM
I/O subroutine is called.

The second way (necessary when a RAM-loaded application program accesses
I/O) uses the I/O peek through feature. Bit 6 of the control register
enables I/O peek through.


    +----------------------------------------------------------------+
    |  				NOTE                                 |
    |  	When using the I/O peek through, ensure that the currently   |
    |  	running subroutine does not reside over the top of the       |
    |  	peek through.                                                |
    +----------------------------------------------------------------+

Accessing screen memory is accomplished in the same way as accessing
the other I/O devices. When accessed, screen memory is seen as 25 lines
of 80 columns. The data is stored row-wise as sequential bytes.

The CRT display circuitry cannot directly display out of the expansion
RAM. A suggested memory manager function is to page whole screen-fulls
of data out of the expansion RAM.


				- 8 -


5.2	Interrupt Processing

The 6502 microprocessor is designed for a simple architecture in which
the lower 32k of the address space is RAM and the upper 32k is ROM. This
allows the microprocessor to fetch the starting address of the first
instruction out of ROM upon reset. The result is that three hardware
vectors are stored in addresses $FFFA - $FFFF.

The memory manager must accomplish the following functions.
   1. Ensure that there is a valid address at each ROM address in the two
   16k expansion blocks that are active. The only exception is if
   interrupts are disabled by a SEI instruction executed before bit 7 is
   set to a 1.

   2. To avoid being interrupted while changing a vector, execute a SEI.

   3. The ROM interrupt vectors in the CBM point to routines in ROM which
   are not accessible when the expansion memory is selected. For that
   reason, the memory manager should a) set the vectors to point at a
   routine that switches to main memory mode, b) call the interrupt service
   routine, and c) restore the expansion memory mode.




5.3	Interrupt Handler Program

The following sample program (Refer to Table 5-1) handles interrupt and
passes control to the ROM routines for processing. The global variable
MEMMAP contains the current contents of the control register. The user
program must first call the INIT routine to load the 6502 interrupt vectors
into the expansion RAM. After that, interrupts are pre-processed by the
subroutines NMI and IRQ. Interrupts are excited by RTIP.


				- 9 -


	Table 5-1. Interrupt Handler Program

; INITIALIZE INTERRUPT PROCESS
;
; ASSUME MEMMAP SETUP
;
INIT	SEI
	LDA MEMMAP
	STA $FFF0
;
; INIT USER IRQ VECTOR
;
	LDA #<IRQ
	STA $FFFE
	LDA #>IRQ
	STA $FFFF

; INIT USER NMI VECTOR
;

	LDA #<NMI
	STA $FFFA
	LDA #>NMI STA $FFFB

	CLI
;
	RTS

; PROCESS IRQ
;
IRQ	STA TMPA		PRESERVE .A
;
	PLA
	PHA
	STA TMPPS
;
	LDA #%00000000
	STA $FFF0
;
; PUSH RETURN FROM INTERRUPT ADDRESS
;
	LDA #>RTIP
	PHA
	LDA #<RTIP
	PHA
;
	LDA TMPPS
	PHA			; PUSH DUMMY STATUS
;
	LDA TMPA		; RESTORE .A
;
; GO TO ROM IRQ SERVICE
;
	JMP ($FFFE)


				- 10 -


	Table 5-1. Interrupt Handler Program (Continued)


; PROCESS NMI
;
; PROCESS NMI
;
NMI	STA TMPA		; PRESERVE .A
				;
	PLA
	PHA
	STA TMPPS
;

;
	LDA #%00000000
	STA $FFF0
;
; PUSH RETURN FROM INTERRUPT ADDRESS
;
	LDA #>RTIP
	PHA
	LDA #<RTIP
	PHA
;
	LDA TMPPS
	PHA			PUSH DUMMY STATUS
;
	LDA TMPA		; RESTORE .A
;
; GO TO ROM IRQ SERVICE
;
	JMP ($FFFA)
;
; RETURN FROM INTERRUPT PROCESS
;
RTIP	PHA
	;
; MAP BACK TO ORIGINAL RAM
;
	LDA MEMMAP
	STA $FFF0
;
; RESTORE OLD .A
;
	PLA
;
; BACK TO USER
;
	RTI
	.END
	.LIB MONITOR



				- 11 -


		A	Memory Map

[ I completely rearranged this table. It was printed sideways on the page
  and repeated earlier info. This would not fit so I omitted the duplicate,
  presenting only the new mappings in the same form as earlier. ]


+-----+--------+------------+-------------------------------------------------+
|     |Control |            |                                                 |
|     |Register|            |      main memory $8000 - $FFFF        [UB1-UB8] |
|     |        |            |      [$0000 - $7FFF is always RAM from UB1-UB8] |
|     |$FFF0   |            |                                                 |
+-----+--------+------------+-------------------------------------------------+
|     |    I/O |___ ___ ___ |              E000                               |
| ___ |    peek|RAM RAM RAM | E800  F000  -E7FF  B000  A000  9000  8000       |
| NO_ |    thr.|___ ___ ___ |              E900                               |
| ROM |CR7 CR6 |ON  S.9 S.A |-E8FF -FFFF  -EFFF -DFFF -AFFF -9FFF -8FFF       |
+-----+--------+------------+-------------------------------------------------+
|     |        |            |                                                 |
|  0  | 0   1  | X   X   X  | I/O  Free   Free   Free  Free  Free  SCREEN     |
|     |        |            |                                                 |
|  0  | 0   0  | X   X   X  | RAM  Free   Free   Free  Free  Free  SCREEN     |
|     |        |            |                                                 |
|  X  | 1   X  | X   X   X  | 2 x 32 K zus\"atl. RAM from 64K in UA1-UA8.     |
|     |        |            |                                                 |
+-----+--------+------------+-------------------------------------------------+

No Rom = 0: marked "for diagnostic".
SCREEN: 2000 bytes for screen memory, and 2096 bytes of available RAM.


				- 12 -


	B.1	connectors 8296

IEEE                                   USER - PORT
====                                   ===========

Arrangement of pins  plug J1/J12       Arrangement of pins  plug   J2

+-----+-------------+-----+--------+   +-----+-------------+-----+--------+
| PIN | SIGNAL      | PIN | SIGNAL |   | PIN | SIGNAL      | PIN | SIGNAL |
+-----+-------------+-----+--------+   +-----+-------------+-----+--------+
|  1  | DIO 1       |  A  | DIO 5  |   |  1  | GND         |  A  | GND    |
|  2  | DIO 2       |  B  | DIO 6  |   |  2  | VIDEO       |  B  | CA1    |
|  3  | DIO 3       |  C  | DIO 7  |   |  3  | /SRQ IN     |  C  | PA0    |
|  4  | DIO 4       |  D  | DIO 8  |   |  4  | /EOI        |  D  |  |1    |
|  5  | EOI         |  E  | REN    |   |  5  | DIAG        |  E  |  |2    |
|  6  | DAV         |  F  | GND    |   |  6  | #2CASSREAD  |  F  |  |3    |
|  7  | NRFD        |  H  |  |     |   |  7  | CASSWRITE   |  H  |  |4    |
|  8  | NDAC        |  K  |  |     |   |  8  | #1CASSREAD  |  K  |  |5    |
|  9  | IFC         |  K  |  |     |   |  9  | VERT DRIVE  |  K  |  |6    |
| 10  | SRQ         |  L  |  |     |   | 10  | HORZ DRIVE  |  L  |  V7    |
| 11  | ATN         |  M  |  V     |   | 11  | GRAPHIC     |  M  | CB2    |
| 12  | CHASSIS GND |  N  | GND    |   | 12  | GND         |  N  | GND    |
+-----+-------------+-----+--------+   +-----+-------------+-----+--------+

[ All IEEE signals are active low ]

    1  2  3  4  5  6  7  8  9 10 11 12
 +--o--o--o--o--o--o--o--o--o--o--o--o--+
 |                                      |  J1 / J2     [PCB edge connector]
 +--o--o--o--o--o--o--o--o--o--o--o--o--+
    A  B  C  D  E  F  H  J  K  L  M  N


   1  2  3  4  5  6  7  8  9 10 11 12
 +------------------------------------+
 | o  o  o  o  o  o  o  o  o  o  o  o |
 |                                    |	   J12        [upright pins on PCB]
 | o  o  o  o  o  o  o  o  o  o  o  o |
 +------------------------------------+
   A  B  C  D  E  F  H  J  K  L  M  N




CASSETTE 1                             CASSETTE 2
==========                             ==========

Arrangement of pins  plug J3           Arrangement of pins  plug J6

+-----+-----+----------------------+   +-----+-----+----------------------+
| PIN | PIN | SIGNAL               |   | PIN | PIN | SIGNAL               |
+-----+-----+----------------------+   +-----+-----+----------------------+
|  1  |  A  | GND                  |   |  1  |  A  | GND                  |
|  2  |  B  | +5V                  |   |  2  |  B  | +5V                  |
|  3  |  C  | CASS MOTOR           |   |  3  |  C  | CASS MOTOR           |
|  4  |  D  | CASS READ          #1|   |  4  |  D  | CASS READ          #2|
|  5  |  E  | CASS WRITE           |   |  5  |  E  | CASS WRITE           |
|  6  |  F  | CASS SWITCH        #1|   |  6  |  F  | CASS SWITCH        #2|
+-----+-----+----------------------+   +-----+-----+----------------------+


    1  2  3  4  5  6
 +--o--o--o--o--o--o--+
 |                    |  J3 / J6                      [card edge connector]
 +--o--o--o--o--o--o--+
    A  B  C  D  E  F

				- 13 -


MEMORY - EXPANSION                              KEYBOARD
==================                              ========

Arrangement of pins  plug J4                    Arrangement of pins plug J5

+-----+-----------+-----+--------+              +-----+--------+
| PIN | SIGNAL    | PIN | SIGNAL |     J4       | PIN | SIGNAL |  J5
+-----+-----------+-----+--------+              +-----+--------+ +---+
|  1  | GND       | 26  | GND    | 25 o  o 50   |  A  | KIN 0  | | o |  A
|  2  | BD0       | 27  |  |     |    o  o      |  B  | |   1  | | o |  B
|  3  |   1       | 28  |  |     |    o  o      |  C  | |   2  | | o |  C
|  4  |   2       | 29  |  |     |    o  o      |  D  | |   3  | | o |  D
|  5  |   3       | 30  |  |     |    o  o      |  E  | |   4  | | o |  E
|  6  |   4       | 31  |  |     |    o  o      |  F  | |   5  | | o |  F
|  7  |   5       | 32  |  |     |    o  o      |  H  | |   6  | | o |  H
|  8  |   6       | 33  |  |     |    o  o      |  J  | V   7  | | o |  J
|  9  |   7       | 34  |  |     |    o  o      |  1  | DEC 0  | | o |  1
| 10  | N.C.      | 35  |  |     |    o  o      |  2  | |   1  | | o |  2
| 11  | N.C.      | 36  |  |     |    o  o      |  3  | |   2  | | o |  3
| 12  | /RAMSEL 9 | 37  |  |     |    o  o      |  4  | |   3  | | o |  4
| 13  | /RAMSEL A | 38  |  |     |    o  o      |  5  | |   4  | | o |  5
| 14  | /RAMON    | 39  |  |     |    o  o      |  6  | |   5  | | o |  6
| 15  | /SELEXP   | 40  |  |     |    o  o      |  7  | |   6  | | o |  7
| 16  | N.C.      | 41  |  |     |    o  o      |  8  | |   7  | | o |  8
| 17  | /CS 9     | 42  |  |     |    o  o      |  9  | |   8  | | o |  9
| 18  | /CS A     | 43  |  |     |    o  o      | 10  | V   9  | | o | 10
| 19  | /CS E     | 44  |  |     |    o  o      | 11  | KEY    | |   | 11
| 20  | /NOROM    | 45  |  |     |    o  o      | 12  | GND    | | o | 12
| 21  | /PENSTRB  | 46  |  |     |    o  o      +-----+--------+ +---+
| 22  | /RESET    | 47  |  |     |    o  o
| 23  | READY     | 48  |  |     |    o  o
| 24  | /NMI      | 49  |  V     |    o  o
| 25  | GND       | 50  | GND    |  1 o  o 26
+-----+-----------+-----+--------+





VIDEO                                           POWER IN
=====                                           ========
                                                                         J8
Arrangement of pins  plugJ7                     Arrangement of pins  plug

+-----+-----------+                             +-----+-----------+
| PIN | SIGNAL    |                             | PIN | SIGNAL    |
+-----+-----------+   +---+                     +-----+-----------+   +---+
|  1  | VIDEO     |  1| o |                     |  1  | AC        |  1| o |
|  2  | GND       |  2| o |                     |  2  | GND       |  2| o |
|  3  | VERT DRIVE|  3| o |                     |  3  | AC        |  3| o |
|  4  | GND       |  4| o |                     +-----+-----------+   +---+
|  5  | HORZ DRIVE|  5| o |
|  6  | KEY       |  6|   |
|  7  | GND       |  7| o |
+-----+-----------+   +---+



				- 14 -


                MEMORY - EXPANSION                          
                ==================                          
                                                            
                Arrangement of pins  plug J9                
                                                            
                +-----+-----------+-----+--------+           
                | PIN | SIGNAL    | PIN | SIGNAL |     J9    
                +-----+-----------+-----+--------+           
                |  1  | GND       | 26  | GND    | 25 o  o 50
                |  2  | BA 0      | 27  |  |     |    o  o   
                |  3  |    1      | 28  |  |     |    o  o   
                |  4  |    2      | 29  |  |     |    o  o   
                |  5  |    3      | 30  |  |     |    o  o   
                |  6  |    4      | 31  |  |     |    o  o   
                |  7  |    5      | 32  |  |     |    o  o   
                |  8  |    6      | 33  |  |     |    o  o   
                |  9  |    7      | 34  |  |     |    o  o   
                | 10  |    8      | 35  |  |     |    o  o   
                | 11  |    9      | 36  |  |     |    o  o   
                | 12  |   10      | 37  |  |     |    o  o   
                | 13  |   11      | 38  |  |     |    o  o   
                | 14  |   12      | 39  |  |     |    o  o   
                | 15  |   13      | 40  |  |     |    o  o   
                | 16  |   14      | 41  |  |     |    o  o   
                | 17  |   15      | 42  |  |     |    o  o   
                | 18  | SYNC      | 43  |  |     |    o  o   
                | 19  | /IRQ      | 44  |  |     |    o  o   
                | 20  | DIAG      | 45  |  |     |    o  o   
                | 21  | PHI2      | 46  |  |     |    o  o   
                | 22  | B R/W     | 47  |  |     |    o  o  
                | 23  | /B R/W    | 48  |  |     |    o  o  
                | 24  | N.C       | 49  |  V     |    o  o  
                | 25  | GND       | 50  | GND    |  1 o  o 26
                +-----+-----------+-----+--------+           
                

POWER EXP. AC                         POWER EXP. DC               
=============                         =============             
                                                                 
Arrangement of pins  plugJ10          Arrangement of pins  plugJ11
                                                                
+-----+-----------+                   +-----+-----------+        
| PIN | SIGNAL    |                   | PIN | SIGNAL    |        
+-----+-----------+   +---+           +-----+-----------+   +---+
|  1  | AC  8V    |  1| o |           |  1  | +9V UNREG.|  1| o |
|  2  | AC  8V    |  2| o |           |  2  | KEY       |  2|   |
|  3  | GND       |  3| o |           |  3  | KEY       |  3|   |
|  4  | KEY       |  4|   |           |  4  | +9V UNREG.|  4| o |
|  5  | GND       |  5| o |           |  5  | GND       |  5| o |
|  6  | AC  8V    |  6| o |           |  6  | +9V UNREG.|  6| o |
|  7  | AC  8V    |  7| o |           |  7  | GND       |  7| o |
+-----+-----------+   +---+           +-----+-----------+   +---+

				- 15 -


          KEYBOARD                
          ========                
                                   
          Arrangement of pins plug J13
                                   
          +-----+--------+        
          | PIN | SIGNAL |
          +-----+--------+
          |  1  | KIN 0  |
          |  2  | |   1  |  13                       1
          |  3  | |   2  | +---------------------------+
          |  4  | |   3  | | o o o o o o o o o o o o o |
          |  5  | |   4  | \  o o o o o o o o o o o o /
          |  6  | |   5  |  --------------------------
          |  7  | |   6  |    25                    14
          |  8  | V   7  |
          |  9  | DEC 0  |
          | 10  | |   1  |
          | 11  | |   2  |
          | 12  | |   3  |
          | 13  | |   4  |
          | 14  | |   5  |
          | 15  | |   6  |
          | 16  | |   7  |
          | 17  | |   8  |
          | 18  | V   9  |
          | 19  | KEY    |
          | 20  | GND    |
          | 21  | N.C.   |
          | 22  | N.C.   |
          | 23  | N.C.   |
          | 24  | N.C.   |
          | 25  | N.C.   |
          +-----+--------+        
          
          RESET
          =====                
                                   
          Arrangement of pins plug J14
                                   
          +-----+--------+        
          | PIN | SIGNAL |
          +-----+--------+  +---+
          |  1  | RESET  | 1| o |
          |  2  | GND    | 2| o |
          +-----+--------+  +---+

				- 16 -


B.2	Connectors, modifications as compared with 8032

                        C B M  8 2 9 6

		 Changes in arrangement of pins

J 4    Memory expansion
+-----------------------------------+
| Pin        Signal                 |
|       old            new          |
+-----------------+-----------------+
| 12  /SEL 4      | /RAM SEL 9      |
| 13  /SEL 5      | /RAM SEL A      |
| 14  /SEL 6      | /RAM ON         |
| 15  /SEL 7      | /SEL EXP        |
| 16  /SEL 8      | N.C.            |
| ...             |                 |
| 19  /SEL B      | /CS E           |
+-----------------+-----------------+


J 8	Power supply
+-----------------+-----------------+
|      8032       |      8096       |
|                 |                 |
| Pin  Signal     | Pin  Signal     |
+-----------------+-----------------+
|  1   8V AC      |  1   AC         |
|  2   +9V UNREG  |  2   GND        |
|  3   GND        |  3   AC         |
|  4   8V AC      |                 |
|  5   8V AC      |                 |
|  6   GND        |                 |
|  7   KEY        |                 |
|  8   14V AC     |                 |
|  9   14V AC     |                 |
+-----------------+-----------------+

J 10    Power supply for hardware expansion
+-----------------------------------+
| Pin        Signal                 |
|       old            new          |
+-----------------+-----------------+
|  1    -9V UNREG |   AC 1          |
|  2    -9V UNREG |   AC 1          |
|  3    KEY       |   GND           |
|  4    +16V UNREG|   KEY           |
|  5    +16V UNREG|   GND           |
|  6    GND       |   AC 2          |
|  7    GND       |   AC 2          |
+-----------------+-----------------+



				- 17 -


[ The following was printed with a dot-matrix printer, with a few bits
  pasted over with typewriter text ]

C	Software addendum


TABLE OF CONTENTS

             64k System Disk...................... 19

	     Add-on-load.......................... 19
	     BASIC 2.0............................ 20
	     BASIC 4.0/40......................... 20
	     BASIC 4.0/80......................... 21
	     Add-on-mon........................... 21
	     Expanded BASIC....................... 24



LIST OF ILLUSTRATIONS


     f i g u r e

         C-1 Modifications to BASIC 2.0........... 20
	 C-2 Modifications to BASIC 4.0/40........ 21




				- 18 -


64k SYSTEM DISK

By using the 64k Expansion Memory Bank[*1] you have given your
system a soft load capability and also expanded program work
space.  We have provided a disk with several programs to
demonstrate these functions.

[*1: Pasted over; it probably read "card" first]

     ADD-ON-LOAD
     ADD-ON-LOAD.SRC
     ADD-ON-MON
     ADD-ON-MON.SRC
     BASIC2.0
     BASIC4.0/40
     BASIC4.0/80
     EXPANDED-BASIC
     EXP-BASIC.SRC
     EXPANDED-DEMO
     STTEST
     TEST1
     TEST2
     TEST3
     TEST4


For your convenience we have recorded these programs in 8050
format on one diskette surface and in 4040 format on the flip
side. Use the corresponding side for your system and make a
back-up copy before use.


A D D - O N - L O A D

This program is a special loader which loads one of three
special versions of BASIC, which we have provided on the
disk, and jumps to the proper entry to execute them. These
versions of BASIC reprogram the CRT controller of your 8032
to become a 40 column display. With this environment, all
old 40-column programs in BASIC 2.0 and 4.0 will run on your
8032.

To load and execute a version of BASIC, type the following
sequence of commands:


     DLOAD"ADD-ON-LOAD" <return>
     RUN <return>

Your CRT should display the following message:


				- 19 -



     64K ADD-ON-LOADER 2-12-81



     SYSTEM NAME?

The cursor will be blinking for you to enter one of the
following system names followed by <return>:



     BASIC2.0
     BASIC4.0/40
     BASIC4.0/80

In a few moments your 8032 will print the logon message from
the program you selected.


B A S I C  2 . 0

This is the 40-column BASIC found in all the 3016 and 3032
business keyboard machines. It was produced by dumping the
ROMs and adding the following patch to re-initialize the CRT
controller:



     D71A    EA EA		[ NOP NOP ]
     D745    A2 04		[ LDX #4 ]
     D747    BD 5E D7		[ LDA $D75E,X ]
     D74A    BC 59 D7           [ LDY $D759,X ]
     D74D    8C 80 E8		[ STY $E880 ]
     D750    8D 81 E8		[ STA $E881 ]
     D753    CA			[ DEX ]
     D754    10 F1		[ BPL $D747 ]
     D756    4C DE E1		[ JMP $E1DE ]
     D759    01 02 03 07 09
     D75E    14 20 28 21 07
     FCD5    20 45 D7		[ JSR $D745 ]


                      f i g u r e     C-1




B A S I C   4 . 0 / 4 0

This is the 40-column BASIC found in all the 4016 and 4032
business keyboard machines. It was produced by dumping the
ROMs and adding the following patch to re-initialize the CRT
controller:

[ Actually, I think this ROM version is the "upgrade" ROM for
3008, 3016, 3032 machines without CRTC. ]

				- 20 -



     FD1B    20 5D FD           [ JSR $FD5D ]
     FD5D    A2 04		[ LDX #4 ]
     FD5F    BD 76 FD		[ LDA $FD76,X ]
     FD62    BC 71 FD           [ LDY $FD71,X ]
     FD65    8C 80 E8		[ STY $E880 ]
     FD68    8D 81 E8		[ STA $E881 ]
     FD6B    CA			[ DEX ]
     FD6C    10 F1		[ BPL FD5F7 ]
     FD6E    4C 00 E0		[ JMP $E000 ]
     FD71    01 02 03 07 09
     FD76    14 20 28 21 07


                      f i g u r e     C-2



B A S I C   4 . 0 / 4 0

This version of BASIC is that supplied in the 8032 60hz
versions. If you have a 50hz machine you probably do not
need this version anyway because it is already in ROM.



E x p a n s i o n   M e m o r y   M o n i t o r   P r o g r a m

The expansion memory monitor source program is provided on
the diskette supplied with this manual. A listing of the
program is provided as an addition to this manual. To run
the monitor program:

          1.  Load the program into the lower 32K of RAM by
	  typing:
	          dload "add-on-mon" <return>

	  2.  Type:
	          run <return>

The following paragraphs describe the commands used in the
expansion monitor program. The commands allow the programmer
to examine or alter expansion memory, examine or alter 6502
registers, execute programs, load or save disk files and load
the expansion control register.


				- 21 -


          :

Format:   : Address [list of bytes]

Purpose:  Alter bytes in memory.

Remarks:  This command is automatically printed onto the CRT
          display preceding the address and data after
	  execution of the display memory (M) command. To
	  alter memory, use the screen editor to change the
	  displayed bytes and press the <RETURN> key. The
	  bytes are altered in the addresses specified by the
	  expansion control register.


;

Format:   ;PC,IRQ,SR,AC,SR,YR,SP	[2nd SR should be XR]

Purpose:  Loads list into 6502 registers.

Remarks:  The list of data following this command is loaded
          into the 6502 hardware registers when a G command
	  is given. This command is automatically printed on
	  the screen preceding the current list of data when
	  an R command is executed. The list can be editeed
	  and re-entered in the same manner as the alter
	  memory command. See the R command for contents of
	  the list.


R

Format:   R

Purpose:  Displays the 6502 registers.

Remarks:  This command displays the contents of a list loaded
          into the 6502 hardware registers when execution is
	  transferred from the monitor. A sample display
	  follows:

	  R <RETURN>

	    PC  IRQ  SR AC XR YR SP

	  ;0400 E262 01 00 FF FF FE


	  The abbreviations are defined as follows:

	            PC  = program counter
		    IRQ = interrupt vector
		    SR  = status register
		    AC  = accumulator
		    XR  = X-index register
		    YR  = Y-index register
		    SP  = stack pointer


				- 22 -


M

Format:   M Address [Address]

Purpose:  Displays bytes from memory

Remarks:  Bytes are displayed from the addresses specified by
          the expansion control register. If one address is
	  specified, 8 bytes are read and displayed on the
	  screen, starting at that address. For more than
	  one adress, a range of bytes is displayed, but
	  always the next even multiple of 8 bytes from the
	  first. The STOP key stops the listing.

	  M 0400 <RETURN>

	  : 0400 00 00 00 AA AA AA AA AA


M

Format:   G [Address]

Purpose:  Start execution.

Remarks:  If an address is not specified, the monitor
          dispatches to the location contained in the PC of
	  the register display. If an address is specified,
	  execution dispatches to that address. If a BRK
	  (00) has been inserted in the user code, execution
	  will return to the monitor and a register display
	  given with the message "BREAK". On display, the
	  registers are loaded with the contents of the
	  register display.


L

Format:   L "name", Device

Purpose:  Load memory

Remarks:  Device number must be 4 or greater for CBM disks.
          The starting load address is implicit in the
	  program load file. The STOP key will break a
	  program LOAD.


S

Format:   S "name", Device, Address, Address

Purpose:  Save memory

Remarks:  A file name must be specified in quotation marks
          followed by a device number, a starting save
	  address and an ending save address.  The STOP key
	  will break a memory save.


				- 23 -


@

Format:   @ [disk command]

Purpose:  Displays disk status buffer

Remarks:  The command immediately followed by <RETURN> will
          read the disk status buffer and print its contents
	  on the screen. The device is set at 8 and the
	  command channel is 15.

	  @ <RETURN>

	  00,ok,00,00

	  If a string follows the @, then that string is
	  transmitted to device 8 channel 15 as a command.

	  @ INITIALIZE 0


name

Format:   name

Purpose:  Load and execute file from disk

Remarks:  When a command cannot be matched to the list of
          known commands, an attempt is successful, the
	  monitor jumos to execute it. [ some text seems missing
	  in this sentence]

*

Format:   * byte

Purpose:  Load expansion memory control register (mapper).

Remarks:  Puts the byte value following the command into the
          expansion control register. When a byte value is
	  not specified, a zero is stored. This value
	  restores the machine to ROM operation.


E X P A N D E D - B A S I C :

This program is a pseud-cache memory system for use with the
8032 and the 64k add-on memory board only. It is loaded into
high memory, ($7800-$7BE0):

           DLOAD"EXPANDED-BASIC"

It is activated by

           SYS 30720

This routine works nearly the same as the DOS-support program


				- 24 -


provided with some Commodore disk systems. It moves the top
of memory for BASIC down to $7800 and resets all the
variables. Its commands are implemented by using an escape
character sequence detected by a tap into the CHRGET routine
in BASIC's zero page.

The EXPANDED-BASIC program is completely protected from
normal BASIC programs--however it is vulnerable to POKE
and machine code programs.

Because the 8032 ROM code is not modified, it is not possible
to add space directly to a BASIC program. The EXPANDED-BASIC
program allows a user to store or "cache" programs and data
in the expansion RAM for ultra high-speed access in
overlaying programs.

The following commands are available:

RECALL

Format:   !R,0:"filename",s(u)(p),[device]

Purpose:  Cache a file from disk.

Remarks:  The file can be USR, SEQ or PRG. The device
          number defaults to 8. The ST variable is set in
	  the same manner as a file OPEN for read.


LOAD

Format:   !L,"program name"

Purpose:  Move data from add-on to BASIC text area.

Remarks:  This command clears the current program and loads
          the named program. Will not work from a
	  program--only direct.


OVERLAY

Format:   !O,"program name"

Purpose:  Move data from add-on to BASIC text area.

Remarks:  This command overlays the current program.
          Variables and data are preserved.
	  [ I think that like with the normal overlaying scheme,
	    the first-loaded program must be at least as
	    big as all overlays used ]



				- 25 -


[ That was the last page of my photocopy of a photocopy of the
  8296 addendum. I suppose I wouldn't be so stupid as to forget
  copying the last page, but there must be one missing:
  there should be descriptions of !E and !Q. On the other hand
  it might even be missing from the very original, since !E
  would have fit on page 25.

  I reconstruct the essential information here. ]


EXECUTE

Format:   !E,"program name"

Purpose:  Execute a cached program.

Remarks:  This command overlays the current program and RUNs it.
          Variables and data are cleared.
	  Basically equivalent to !L but for use within
	  a program.


QUIT

Format:   !Q

Purpose:  Quit the memory manager.

Remarks:  The tap into the CHRGET routine is restored to the
          power-up default. None of the expansion manager commands
	  are recognised anymore from now on.


[ end of the 8296 addendum ]

: vi:set tw=75
-Olaf.
--
___              Copyright 1995 Olaf 'Rhialto' Seibert. All Rights Reserved.
\X/    You are not allowed to read this using any kind of Micro$oft product.