Post Reply 
Hand Held Products 71M/M eprom carrier question
06-16-2020, 06:51 PM
Post: #7
RE: Hand Held Products 71M/M eprom carrier question
Good news, although not without some extra work: I successfully burned the HN27256G that came originally with the HHP 71M/M with a copy of one of my Math roms and it worked. Initially, I tried to use an NM27C256BQ thinking that the CMOS part would consume less power. The rom was successfully recognized, but as soon as I made heavy use of the matrix functions in it, a crash occurred and I got a "Memory Lost". I then programmed the same EPROM that came with the 71M/M (the said HN27256G) and this one has been working fine. I can only assume that the NM27C256BQ produces some spikes in the power supply that the HP-71B doesn't like.
Find all posts by this user
Quote this message in a reply
Post Reply 


Messages In This Thread
RE: Hand Held Products 71M/M eprom carrier question - cmurillo - 06-16-2020 06:51 PM



User(s) browsing this thread: