Found a NOS stash of ST62E28 ROM MCUs. How were they programmed?

[Yansi]

Hello,

I have found a NOS stash of ST62E28 ROM MCUs.  Out of curiosity, does anyone have a documentation how these were programmed? I can google the name of the tool, heck I could even find one with the software to run it, but I am more interested how the programming interface was done on these old MCUs.

I have a ST62E28CF1 (datasheet), which is a cerdip with UV erasable ROM inside.  From the datasheet that can be easily found on google, I can clearly see there is a 12.5V Vpp pin. However I do not see any further description how is the data transfered inside.

Have anybody used these 8bit oldtimers?

Thanks

[mikeselectricstuff]

A lot of these early EPROM MCUs had a programming interface identical to EPROMs, just needing a pinout adapter and a standard EPROM programmer.

[amyk]

You are in luck, a year ago someone asked on here about how to program a different member of the ST62 series, and I found the programming spec:

https://www.eevblog.com/forum/microcontrollers/need-to-programm-a-st62t10-mcu-help-finding-a-cheap-programmer/msg1620967/#msg1620967

[Yansi]

Nice one! Thanks for sharing. Have had a quick look, it didn't look much like any regular EPROM.