Reading ROMs

Marc Verdiell marc.verdiell at
Sun Sep 6 18:38:01 CDT 2015

Jay, Mike, John,
Thanks for the helpful information. It just dawned onto me that these were
"write once" PROMs, not modern EEPROMs. Duh. So you get one shot at doing it
The Data I/Os on ebay seem to be quite a bit more than $100 right now, I'll
keep looking. I guess none of the modern ebay Chinese ones would do? Also
where can you get the blanks? Any modern equivalents here too?

Jay West wrote:
The Data I/O 29B works perfectly for those old fusable link proms.

John Robertson wrote:
One can pick up a Data I/O 29B and Unipak II off eBay starting around 
$100USD (ish). There is a very good support group on yahoo groups:

Mike Loewen wrote:
I used a Data I/O 29B programmer to burn the PROMs, with a Unipak 2B. 
The blank PROMs were variously Signetics N82S141, MMI 6341-1 and National 
74S474. Along with the 12821A HP-IB board, you also need a Boot Loader 
PROM, 12992H (12992-80004). The boot loader PROM is a Signetics N82S129 or 
equivalent. For installation information about the firmware PROMs, see 
manual 12791-90001 (HP 1000 M/E/F-Series Firmware Installation and 
Reference Manual). For boot loader information, see manual 12792-90001 (HP 
12992 Loader ROMs Installation Manual).

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