Mostek STDbus DEBUG board and ROMs

This page was last updated Aug 6 2023 (c) Herb Johnson all rights reserved. Search my Web site to find other Web page content of interest. My home Web page for STDbus boards is at this link. My contact info is at the end of this WEb page.

[debug STDbus card]

MDX-DEBUG <-- Mostek EPROM/ROM board with ASMB DDT ROMs
serial SMC COM 2502 UART, SMC 5026 baud rate IC, 5 ROMS. 4 boards available, some with plastic ROMs. 

ROMs dumped & disassembled. One ROM had bit errors, one ROM no errors but repaired pin.

These ROMs contain Mostek's ASMB-80 and DDT-80. See MOSTEK documentation for manuals
MDX-Debug manual (board with these ROMs), and MDX-EPROM/UART manual (board without ROMs), and ASM-80 DDT-80 Operation manual. 

From the 2023 creator of the ASM80B.ASM and DDT80.ASM files:

"I have no other binaries for the MOSTEK programs [in your set of ROMs]. DDT-ROMs can be found at, 
where only parts of the code look equal to the DDT which works with the ASMB [in your ROMs]."

"The ASM-80 consists of two parts, the assembler and an editor. I owned the source of the assembler
 part for more than 40 years. I think it is an original source by MOSTEK. Maybe we got it at that time
 together with an SMB-80 board. Since than I had the dream to translate it. The source looks a 
little strange and I made some changes in the form not in the contents. At last I could translate 
it with the TASM assembler. The result matches your ROM with only one byte difference. The original
 jumps into a 3 byte command where the target address is null (NOP), so it doesn't matter."

"The DDT-80 I disassembled from your binary and the result matches your ROM exactly. 
The editor source [disassembly for the remaining ROM code] is still in progress. I will send it soon. - Aug 1 2023"

Meanwhile, I (Herb Johnson) disassembled the ROM code for the editor source. It's included in the ROM ZIP files. 

References to related MOSTEK code and hardware

Magnus Hagemann has a Mostek SYS-680F Z80 develoment system, running CP/M, the European version of the AID-80F system. The boards use a Euro-style connector of sorts to its backplane. The boards are labled "made in Germany" and apparently date from the late 1970's. There's two Shugard 801 drives, and a WD1771 based (soft sectored) floppy controller. The site includes disk images and PDFs of Mostek manuals for the system.

There's numerous references on those Web pages, to the deramp site's archives of Mostek AID-80F materials, including an emulator.

Notes on the ZIP file

a ZIP file of the MOSTEK DEBUG ROMs and disassemblies. The Mostek manuals for the MX-DEBUG board and ASM/DEBUG are available as PDFs, ask.

debug.bin - Binary from five 2716-type PROMS by Herb Johnson 
          - verified from 4 sets of EPROMs one ROM had bit errors
          -C000H to E7FFH 
debug_jmps.txt - MOSTEK debug board jumpers
m_debug.asm - raw disassembly of binary by Herb Johnson
m_debug_4dec.cfg - guidance for disassembler

DDT80.ASM - source code as described, ORG 0E000H to E7FFH
     - enter D000H
     - closely matches disassmbly of m_debug.asm  

ASMB80.asm - source code as described, ORG 0C000H to D48AH
     - closely matches disassembly of m_debug.asm debug/ASMB ROMs at 0C000H to about 0CF8CH
     - then tables of bytes to about 0D48AHH where ASMB80.ASM ends

d400.bin, .asm, .cfg -  unresolved ROM code is the D48BH to DFFFH, an editor? some utilites?
     - disassembled by Herb Johnson 
     - D48B seems to be an entry point, calls DEBBH and DEB3H, more work

Herb Johnson
New Jersey, USA
here's how to email @ me and to order

Copyright © 2023 Herb Johnson