The NatSemi MM2716Q is definitely the ‘normal’ single rail EPROM. The TMS2716 is the TI version that is 3-rail. A quick test would be to measure pin 19 in circuit. If this is 12v, then it’s expecting a TI part.
Does your reader have any other ‘brands’ of 2716 you could try? What about trying to read it as a 2732? Looking at the pinouts it looks like the only difference is pin 21 which is Vpp (programming voltage) on a 2716 and A11 on a 2732. You’ll get a 4k buffer but hopefully half of it will have your data… Ian > On Jun 15, 2015, at 2:19 PM, Chris Osborn <fozzt...@fozztexx.com> wrote: > > > On Jun 15, 2015, at 1:56 PM, Ian McLaughlin <i...@platinum.net> wrote: > >> All zeroes is really strange - a blank EPROM is all ones, so it’s not that >> it got exposed to UV light. > > It definitely does seem strange. I wonder if maybe it’s a TI style 2716? It’s > a National Semiconductor MM2716Q. > > -- > Follow me on twitter: @FozzTexx > Check out my blog: http://insentricity.com > > > > > > --- > Filter service subscribers can train this email as spam or not-spam here: > http://my.email-as.net/spamham/cgi-bin/learn.pl?messageid=4BC99E8013A411E5A0B78C5F93ED0201
