Cannot read a TMM2365P (2764)

[andyjh]

I'm trying to read a Toshiba TMM2365P, but this is not on the device list for my Dataman Mem-Pro. This Mask ROM is supposed to be pin compatible with a 2764D, although that is not on the supported device list either. I have tried selecting a generic 2764, and that does not read either,

Is there any way I can read this ROM chip? I need to read it, so I can burn it to a 2764

thanks

Andy

[Dataman (Neil Parker)]

Hello Andy,

The implementation of the Generic 2764 and other EPROMs is OK - also with the TMM2764 device (the D means the ceramic DIP package).

A brief look at the datasheet for these two devices reveals that the TMM2365P is not pin compatible with a 2764.

After further analysis of the TMM2365P device we have determined that we are able to implement a read function for this device, it requires us to implement a procedure which finds the proper combinations of enabling signals.

This support will require several days of engineer time so cannot be offered free of charge. The support can be locked to the s/n of your programmer. We would need one sample chip to be able to finalize the read algorithm. Would you be able to provide this?

If you can send me a PM I will provide a quotation for the support.

Best regards

Neil Parker
Dataman Programmers

[andyjh]

Hi Neil,

Thanks for the reply, I have been studying datasheets and the schematic of the equipment that this TMM2365 has come from, and I have come up with a way to read this chip using the 2764 profile.

Although the solution is straight forward, I took time checking it was all OK, the solution is to disconnect pins 26 and 27 from the programmer, and connect them to pin 28, so basically that means CE1 and CE2 are held high - and that reads all OK.

Though I doubt anyone else will come across this particular chip - it is out of a circa 1983 piece of equipment !

thanks

Andy