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Stunning Motorola 68000 system made by Computer System Associates USA circa 1984

Bruce Tomlin

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Jan 6, 2010
Messages
159
Location
San Antonio, TX
Now that I know the ECB is involved, I can see your problem. That version of petebug definitely won't work with the ECB.

ECB:
010040 ACIA 1 control/status
010041 ACIA 2 control/status
010042 ACIA 1 data
010043 ACIA 2 data

CSA:
010041 ACIA 1 control/status (unused ACIA)
010043 ACIA 1 data
010061 ACIA 2 control/status (the keyboard unit)
010063 ACIA 2 data

So why were you asking for FD0041 ACIA addresses?

Anyhow, here are the only references to the ACIAs in the petebug code, you should be able to hex edit those easily enough. 61/63 is the one used for the display, 41/43 is initialized but not used.

Code:
0087C8: 0839000100010061  L0087C8: BTST    #1,$010061.L
0087D2: 13C000010063               MOVE.B  D0,$010063.L
0088BE: 0839000000010061           BTST    #0,$010061.L
0088CA: 103900010063               MOVE.B  $010063.L,D0
008E10: 13FC000300010061  L008E10: MOVE.B  #$03,$010061.L
008E18: 13FC001500010061           MOVE.B  #$15,$010061.L
008E20: 13FC000300010041           MOVE.B  #$03,$010041.L
008E28: 13FC001500010041           MOVE.B  #$15,$010041.L
 

Pt68k5

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Feb 18, 2010
Messages
42
this is the version of petebug that is on the MECB and match the manual for the MECB, The extra-wide system that has the custom 68000 board
Has the 2 Acia ports the first one is at FD0041 and the second one is at FD0063 and then it has the 2 PIA'S (6821) at FD0000 (keyboard PIA) and FD0001 (display PIA)

So I have 2 different systems I am trying to get working the one with the serial display interface need the missing 8751 recreated which decodes the serial data from the MECB.
The other system(extra-wide was missing the Cpu and eproms, there were 2 eproms on the board that are not marked, I installed a 68000 and got noting, So I am wanting to get a serial port working
on it as a starting point, the manual I posted has a lot of info about the second version of the extra-wide system. then could work on geting the pia's talking to the diaplay board which is connected to
The pia's on the Cpu board controlls the display board operation. the extra-wide system also had a version of petebug on it

here are links to the eproms which I got another person to put out there I tried burning and putting the eprom in my board but no change.


and the manual here


Sorry if this is confusing
 

Bruce Tomlin

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Messages
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Location
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Okay, I'll see what's in all that stuff. I can tell you right away that the manual has display messages that are not in the petebug posted earlier.
 

Bruce Tomlin

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Messages
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Location
San Antonio, TX
I've been reading the documentation, and apparently the wide board doesn't have an 8751 after all. It uses two PIA chips, U36 for the keyboard and U37 for the display, via that edge connector cable.

Getting an 8751 to control the suitcase display could help in writing 68000 code for the wide board, but without that much later version of the petebug roms, the wide version will be hard to get working. The documentation is a bit fuzzy about the "blank display bit", but it looks like everything else is explained. And at least you have a proper copy of TUTOR which you can use to tickle the PIA chip manually.

I've assembled a version of that early petebug with the ACIA addresses set up for ACIA2 on the ECB, on the chance that it will help getting a suitcase unit working with the serial display. I'm not sure why the original ROM would be assembled for different ACIA addresses than the ECB.
 

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  • petebug-ecb.zip
    12.4 KB · Views: 5

Pt68k5

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Feb 18, 2010
Messages
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Bruce looks good, I will try later today if I get time.
Just for note on the stacked system the serial display board connects ACIA2.

I had tried getting a 89s52 working with basic on the serial board but I could never get it talking to a pc host, on the ECB I connected port2 to a host pc and would get data showing but nothing that made an since.
this all more then a year ago that I played with the stacked system.

Thank you for all the good work
Tony
 

Pt68k5

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Feb 18, 2010
Messages
42
Here is capturing the serial port output in powering on the system with your version of petebug
P 00P!00P"00P#00P$00P%00P&00P'00P(00P)00P*00P+00P,00P-00P.00P/00P000P100P200P300P400P500P600P700P800P900P:00P;00P<00P=00P>00P?00P@00PA00PB00PC00PD00PE00P 7DP!7FP"3FP#3FP$3FP%00P&3EP'73PD01

here is the orginal petebug rom at boot
P 00P!00P"00P#00P$00P%00P&00P'00P(00P)00P*00P+00P,00P-00P.00P/00P000P100P200P300P400P500P600P700P800P900P:00P;00P<00P=00P>00P?00P@00PA00PB00PC00PD00PE00P

So it looks like your version output a few more Bytes. both version output on the same port.
I have no idea on how to decode the data above, but you may know how?

Tony
 

Bruce Tomlin

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Messages
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Location
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P = first byte
0x20 + digit index, strictly left-to-right row-by-row, first columns are " " ( . 4 : @ D E
hex ascii of the high nibble
hex ascii of the low nibble

Most of that is just clearing every digit position to turn all LEDs off.
P 7DP!7FP"3FP#3FP$3FP%00P&3EP'73 - 7-segment data of "68000 UP" (7D 7F 3F 3F 3F 00 3E 73)
PD01 - setting a status LED in the second row from bottom (digit offset 0x24)
so it's probably waiting for keyboard input now

Keyboard input is ASCII 0-9, A-F, CR, H, I, R

The interesting thing is that your shorter dump stopped with the first P of sending "68000 UP", maybe the 68000 tried to access one of those incorrect ACIA addresses and locked up for no chip being there, or lack of DTACK, but that is an odd place to lock up.
 
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Pt68k5

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Feb 18, 2010
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A little bit. I burned the PETEBUG EEPROMs and plugged them in, but the CPU board isn't doing anything except turning on the HALT light. So I'm going to have to debug the CPU card to figure out what's going wrong.
Hello
Have you tried anything else with your system? pin "1" of the 2764 should be buy the handle of the zif sockets
if it is working you should get 68000 UP on the seven segment displays
 

Pt68k5

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Feb 18, 2010
Messages
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Now I know a little more about decoding some of the messages, the next trick would be to get a 89S52 working to decode the display and keypad talking to the serial port at 9600 to the ECB
Which is asking alot since my writing code from scratch is none.
 

Bruce Tomlin

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Messages
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Location
San Antonio, TX
You could maybe also try to create a display simulator on a PC written in C, just show all the LEDs as * or o, and decode the 7-segment data.

Code:
00    blank    53    ?       73    P
06    1        5B    2       76    H
07    7        5C    o       77    A
39    C        5E    d       78    t
3E    U        66    4       79    E
3F    0 / O    6D    5 / S   7C    b
4F    3        6F    9       7D    6
50    r        71    F       7F    8
 

gottahack

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May 14, 2022
Messages
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Here is capturing the serial port output in powering on the system with your version of petebug
P 00P!00P"00P#00P$00P%00P&00P'00P(00P)00P*00P+00P,00P-00P.00P/00P000P100P200P300P400P500P600P700P800P900P:00P;00P<00P=00P>00P?00P@00PA00PB00PC00PD00PE00P 7DP!7FP"3FP#3FP$3FP%00P&3EP'73PD01

here is the orginal petebug rom at boot
P 00P!00P"00P#00P$00P%00P&00P'00P(00P)00P*00P+00P,00P-00P.00P/00P000P100P200P300P400P500P600P700P800P900P:00P;00P<00P=00P>00P?00P@00PA00PB00PC00PD00PE00P

So it looks like your version output a few more Bytes. both version output on the same port.
I have no idea on how to decode the data above, but you may know how?

Tony
Just a guess, but it looks like 'P' starts a display command, following letter specifies which part of the display it goes to, followed by display contents.
 

Pt68k5

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Feb 18, 2010
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Ok, it help but first I need to get the multiplexing of the displays down first and then start working on decoding the data stream to display on the displays
then after that to get the keypad working.

Gottahack question is your system working now?
 

Pt68k5

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Feb 18, 2010
Messages
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Here is tutor 1.3 as a zip file that runs on the system that you have gottahack
It needs to be burned to 2764 eproms and connect to J3 which is port 1 it should connect at 9600,8,n,1 for the settings
 

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  • Tutor_CSA.zip
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Pt68k5

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Feb 18, 2010
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Hello Gottahack,
Any progress on getting your system to work, IF not I am in California and could repair it for you?
Can you post pictures of the lower board?
 

gottahack

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May 14, 2022
Messages
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No, haven't worked on it yet, other things had priority. The lower board is just the Motorola MEX68KECB board, I think they're all the same.

Any luck on the display multiplexing? If you don't have it yet, I decoded the keyboard-generated serial characters.
 

gottahack

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May 14, 2022
Messages
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It's pretty simple. One character per key press. 0 thru F is '0' thru 'F' in ASCII. HEX is 'H', RESET is 'R', BREAK is 'I' and ENTER is CR (x0d).

Edit: Oh, looks like Bruce Tomlin beat me to it.
 
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Pt68k5

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Feb 18, 2010
Messages
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Any help on receiving serial data stream and multiplexing it on 89s52 which is another version of the 8051 (same pinout)
I have play some with multiplexing and can only get 4 seven segment to show the correct info, this is just using embedded text.
 
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