TMS7041 Internal ROM Dump
Par Torlus, Thursday 24 September 2009 à 09:09 :: Oldies :: #230 :: rss
Exelvision is an obscure brand of computers from France, that operated in the 80s, their most famous home computer being the Exl 100.
For more information, here is Fabrice Montupet's Exelvision-related website, which is the largest source of information you can find on this company and their computers.
The Exl 100 embeds two CPUs : a TMS7020, and a TMS7041, the TMS7020 being the main CPU, whereas the 7041 is used as a microcontroller, and is responsible for most I/O related stuff, including screen display (for instance, it stores in its internal ROM the character table).
Until now, the contents of this ROM hadn't be retreived, so it was an issue for emulator writers. However, someone on Silicium's forum found this newsgroup thread, explaining a way to retreive the internal ROM contents of a PIC7040, which is very close to the TMS7041, so I decided to give it a try.
For this purpose, I used my favorite FPGA board, to make the TMS7041 output its internal ROM to the board's SRAM, then dump the SRAM contents over a serial port. Here is a picture of the whole stuff :
After some attempts, it seems that it worked fine :) Emulator writers are currently analyzing the ROM contents, and have a good feeling about it.
It should hopefully lead to a better understanding and emulation of these obscure machines.

Commentaires
1. Le Friday 13 November 2009 à 17:23, par gilles
Ajouter un commentaire
Les commentaires pour ce billet sont fermés.