Search Posts:

PTCO 2KRO 1702A 2K ePROM

SHARE

Return to Threads

  PTCO 2KRO 1702A 2K ePROM by Bill Degnan - 04/17/2013 15:25
Processor Technologies PTCO 2KRO 1702A 2K eProm Board
Processor Technologies PTCO 2KRO 1702A 2K eProm Board, .cir 1976. Click for larger View.


Here is a dump extracted from three 1702-A ePROMs installed in a PTCO 2KRO board.

The dump below consists of the three 1702-A ROMs. The first is (my guess) some sort of 8080 monitor program or bootstrap, the second is the PTCO VDM-1 board initialization routine, and the third may be additional instructions for a 3P+S card to interface to run with a teletype (ASR33?). Just a guess. I will update the thread after I get a chance to test. I also have to determine the memory locations of each. The card is not documented on the web. The jumper W is in the "1" position. I am guessing 1 = C000, 2 = D000, 3=E000, 4=F000 - I will update this thread after I run some tests.



00: 31 FF 2F CD 06 80 CD 45 80 FE 3A C2 06 80 CD 2A
10: 80 57 C8 CD 2A 80 67 CD 2A 80 6F CD 2A 80 CD 2A
20: 80 77 23 15 C2 1E 80 C3 06 80 CD 45 80 CD 3D 80
30: 07 17 17 17 5F CD 45 80 CD 3D 80 83 C9 D6 30 FE
40: 0A D8 D6 07 C9 DB 00 E6 40 CA 45 80 DB 01 D3 FF
50: E6 7F C9 00 00 00 00 00 00 00 00 00 00 00 00 00
60: 31 FF 2F CD 66 80 CD C2 80 FE 3A C2 66 80 CD 8A
70: 80 57 C8 CD 8A 80 67 CD 8A 80 6F CD 8A 80 CD 8A
80: 80 77 23 15 C2 7E 80 C3 66 80 CD C2 80 CD 9D 80
90: 07 17 17 17 5F CD C2 80 CD 9D 80 83 C9 D6 30 FE
A0: 0A D8 D6 07 C9 DB 02 DB 02 31 FF 2F 21 00 00 CD
B0: C2 80 B7 CA AF 80 77 BE C2 B8 80 23 CD C2 80 C3
C0: B6 80 DB 00 E6 01 C2 C2 80 DB 00 E6 01 CA C9 80
D0: DB 02 E6 7F C9 00 00 00 DB 00 E6 80 CA D8 80 78
E0: D3 01 FE 0D C0 E5 AF 6F 67 EB EB 2C C2 E9 80 24
F0: C2 E9 80 E1 C9 00 00 00 00 00 00 00 00 00 00 00

00: 22 F9 2F 21 00 00 39 31 F8 2F E5 D5 C5 F5 CD B3
10: 81 F1 C1 D1 E1 F9 2A F9 2F C9 78 E6 7F FE 0C CA
20: 35 81 FE 5F CA 8E 81 FE 0D CA 9D 81 FE 7F C8 FE
30: 20 D8 C3 80 81 3E 00 D3 C8 32 FD 2F 21 00 CC 11
40: 40 00 06 10 36 0D 19 05 C2 44 81 C3 4E 81 21 C0
50: CF 22 FB 2F 36 A0 23 36 0D C9 3A FD 2F 3C E6 0F
60: 32 FD 2F D3 C8 2A FB 2F 11 40 00 7D E6 C0 6F 19
70: 7C E6 03 F6 CC 67 C3 51 81 2A FB 2F 3E 3F A5 C9
80: CD 79 81 FE 3F C8 3E 7F A0 77 23 C3 51 81 CD 79
90: 81 C8 36 0D 2B 22 FB 2F 3E 80 B6 77 C9 CD 79 81
A0: 36 0D CD A8 81 C3 5A 81 DB FF E6 40 C8 CD C2 80
B0: DB 03 C9 DB FF E6 01 CA 1A 81 C3 D8 80 00 00 00
C0: 31 FF 2F 21 00 00 CD D7 81 B7 CA C6 81 77 D3 FF
D0: 23 CD D7 81 C3 CD 81 DB 00 E6 01 C2 D7 81 DB 00
E0: E6 01 CA DE 81 DB 02 C9 00 00 00 00 00 00 00 00
F0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

00: CD 35 81 CD 45 80 DB 01 C3 60 82 CD 00 81 DB FF
10: FE 10 CC 35 81 DB FF FE 08 CA 04 C0 C3 03 82 00
20: 45 0A 41 20 53 49 55 0D 44 52 4A 4E 46 43 4B 54
30: 5A 4C 57 48 59 50 51 4F 42 47 00 4D 58 56 00 00
40: 33 00 2D 20 07 38 37 0D 24 34 27 2C 21 3A 28 35
50: 22 29 32 23 36 30 31 39 3F 26 00 2E 2F 2E 00 00
60: FE 1B CA 7A 82 FE 1F CA 82 82 21 1F 82 5F 16 00
70: 19 3A 00 C9 5F 19 46 C3 0B 82 3E 20 32 00 C9 C3
80: 03 82 AF 32 00 C9 C3 03 82 00 00 00 00 00 00 00
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
A0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
B0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
C0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
D0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
E0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
F0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Reply
  Update to PTCO 2KRO by Bill Degnan - 12/19/2015 15:18
Processor Technologies PTCO 2KRO 1702A 2K eProm Board
View of the 2KRO jumpers. Click for larger View.


I installed this S-100 board into my IMSAI 8080 to see if I can read the ePROMs from the front panel having already verified the chips are OK (see also 1702A repair below). I have no manual for this board (have one?).

A little experimentation revealed how to assign the page address using jumpers 11-15. In the photo above, note how jumper 15 is set to the top jumper (or "high") post and the rest are connected to the "low" posts. This combination sets the starting page address of the board to 80H (8000 0000 Hex). When I change jumper set 15 to the low post, starting page address becomes 0000 0000 Hex.

The wait state jumper posts read W and 1-4. The photo shows how the jumper is set to connect to jumper 1, indicating no wait state needed (I believe).

Reply
  Repairing Legs of a 1702A ePROM by Bill Degnan - 12/22/2015 15:25
1702A 2K eProm Repair
This photo shows a 256 byte 1702A ePROM with a broken pin, since repaired (note silver-colored pin 2nd from right). The ePROM repair was a success, but given its fragile state I replaced from use and installed a newer 1702A onto the ePROM board, see photo above. Fortunately I had an image of the ePROM and was able to make a replacement chip. Click for larger View.



Reply

Resources:


Buy a Commodore Computer Poster

Popular Topics and FAQs


  • Commodore B Series Tips and Tricks
  • Aerocomp TRS 80 M 1 Expansion Unit DDC
  • Items Wanted
  • Lobo Max 80
  • Zenith Z-19-CN
  • Prototype PET 2001 photo
  • Using Toggle Switches to Analyze Memory
  • Commodore Disk Archive Project
  • PET 2001 Prototype at Gametronics 1977
  • Jim Butterfield Photo
  • IMSAI 8080 With Processor Tech. Cutter
  • Secrecy is the keystone of all tyranny
  • Cromemco System Three
  • Northstar Horizon - Boot Problem
  • Computer History and Restoration Links
  • Commodore BX-256-80 - 8088 Co-processor
  • S-100 board testing with Z-80 ICE
  • Donner 3500 - an early portable computer
  • Digital (DEC) PDP 11/05 NC Assembly
  • Univac 1219 rescue
  • IMSAI 1.4 BASIC vs. MITS 8K BASIC
  • Fido BBS listing node list 6-13-1986
  • PDP 8e
  • MITS 88-2 SIO (2SIO) for BASIC
  • Visual Technology Inc Model 1050
  • Amiga 2500 Restoration
  • The Evolution Of IBM Computers
  • Replacement teletype print hammer head
  • Archiving and Copying Software 101
  • Computers Built 1940 - 1950
  • CBM B-520 (a.k.a B256-80 or B500 256)
  • RCA COSMAC Microkit
  • Commodore 64K C-116 Mods
  • MITS 8800b Turnmon 9600 baud
  • Catweasel, 8in and 5 1/4
  • Raspberry Pi as Gateway to Internet
  • Digital PDP11 late 1969 early 1970
  • PDP 11/40 72 inch cabinet model
  • PDP 11/40 Industrial 11 model
  • Digitial MicroVAX 3100 30 System
  • Digital VAX 4000-200
  • Commodore 64 / 1541 DRIVEKNOCK
  • Booting the System Using RL02 drive
  • PACS: Reflections by Kathleen Mauchly
  • Tele-Graphic Computer Systems Inc.
  • Commodore B Series SID Jukebox?
  • Installing Core into PDP 11/40
  • Setting Up OpenVMS 7.1 DNS CLERK
  • Felt-Tarrant Comptometer Model J
  • NextStation Color
  • Digital Rainbow (PC100-B2)
  • 1970 Compusad Compulogical Tutor
  • Archiving Papertapes Using DSI NC 2400
  • 1976 P.C.C. Features the MAI JOLT 6502
  • 1961 Beckman DEXTIR Computer
  • UNIVAC 1 and UNIVAC File Computer 1
  • Past Issues:


    MicroPac80 classroom

    This image was selected at random from the archive. Click image for more photos and files from this set.