Read the code of a very old microcontroller - Page 1
Forum section: electronics / general

author: fabiodl
author_rank: Frequent Contributor
timestamp: June 10, 2014, 08:31:11 am
content: I would like to check the code of a tmp42c66pa 4 bit toshiba microcontroller. Do you know if it is possible/ any programmer able to do that?

author: amyk
author_rank: Super Contributor
timestamp: June 10, 2014, 08:41:14 am
content: That's a mask ROM MCU, so it's unlikely to have a programming interface. The most effective way would probably involve decapping and then optically reading the bits out (there's only 8192 of them...); this processcan be automated.

author: Kjelt
author_rank: Super Contributor
timestamp: June 10, 2014, 10:26:57 am
content: You're better off to try to reverse engineer the behaviour in the application and try to mimic it with a modern uC.

author: fabiodl
author_rank: Frequent Contributor
timestamp: June 10, 2014, 12:55:34 pm
content: @amyk thank you for the link, that is amazing, but I surely don't have the hardware nor the competence to do that.

author: fabiodl
author_rank: Frequent Contributor
timestamp: June 10, 2014, 01:48:25 pm
content: I found thishttp://bitsavers.informatik.uni-stuttgart.de/pdf/toshiba/_dataBooks/1984_Toshiba_Microcomputer_LSI_Data_Book.pdfIt seems that to program you had to send the code by a PAPER TAPEyes, probably reading it is impossible

author: Stray Electron
author_rank: Super Contributor
timestamp: June 10, 2014, 06:52:33 pm
content: Why does it matter what was used to send the code into the manufacturer? It's all just ones and zeros regardless of the media. Either the device is readable or its not! FWIW most devices are readable but manufacturers keep the methods a secret to prevent reverse engineering. I have a device that was specifically made to dump code from the MC 68705s.FWIW there are still some of us hard core types that still have working PT readers and punches! Mine is on (one of) my Intel MDS 800.

author: fabiodl
author_rank: Frequent Contributor
timestamp: June 11, 2014, 07:22:06 am
content: Quote from: Free Electron on June 10, 2014, 06:52:33 pmYes, you are completely right. The correct wording would have been "as the chips were not programmed electrically, I think it is unlikely there is a modern programmer able to write the program and read the content back, with an interface like the keil software".Quote from: Free Electron on June 10, 2014, 06:52:33 pmdo you know if there's any such device compatible with the tmp42c66p ?Quote from: Free Electron on June 10, 2014, 06:52:33 pmwow, this is really cool

author: miguelvp
author_rank: Super Contributor
timestamp: June 11, 2014, 07:29:44 am
content: I threw away my used punch cards, but I have some around used as book marks inside very old books!

author: Kjelt
author_rank: Super Contributor
timestamp: June 11, 2014, 08:08:26 am
content: Quote from: Free Electron on June 10, 2014, 06:52:33 pmSounds more like a hoarder type then a hard core type to me(joke not to offend you)I got rid of old tech if at least all applications from that computer or system can be transferred to the current state of technology, if not then you try to keep it alive and running as long as possible but everybody knows that time will win eventually.

author: 22swg
author_rank: Frequent Contributor
timestamp: June 11, 2014, 08:30:41 am
content: Paper tape saved the world.... ( taken at Bletchley Park.)

author: westfw
author_rank: Super Contributor
timestamp: June 11, 2014, 08:43:07 am
content: Various sites report that there are "somewhat dodgy" companies that will read code from processors for you (even if "protected") for as little as ~$100. () (price dependent on difficulty, or something. Other chips: $25k. But it might be worth checking out.)

author: Jeroen3
author_rank: Super Contributor
timestamp: June 11, 2014, 09:24:35 am
content: Yes, these companies exist. Some larger regular companies might even be capable, but they won't tell you.

author: Refrigerator
author_rank: Super Contributor
timestamp: June 14, 2014, 05:56:55 pm
content: Quote from: westfw on June 11, 2014, 08:43:07 am$25k is pocket change.

author: M. András
author_rank: Super Contributor
timestamp: June 14, 2014, 09:02:42 pm
content: Quote from: Refrigerator on June 14, 2014, 05:56:55 pmdo mind donate some change to the crowd?