On 31/10/2016 2:23 AM, Gerrit Heitsch wrote: > On 10/30/2016 06:59 PM, Francesco Messineo wrote: >> On Sun, Oct 30, 2016 at 6:50 PM, Gerrit Heitsch >> <gerrit@laosinh.s.bawue.de> wrote: >>> On 10/30/2016 06:20 PM, Francesco Messineo wrote: >>>> >>>> Hi all, >>>> I started working on my 3032 (2001-32), it will be a long project, >>>> since it's mostly a pile of dirt and rust (I've found it in this state >>>> 15 years ago, in a side of the street). >>>> I've seen the UD3 ROM socket populated, here's a picture: >>>> >>>> https://www.dropbox.com/s/xx5o8rd6ng75ac8/UD3-orig.jpg?dl=0 >>>> >>>> I'll be reading the EPROM in the next days, does someone have an idea >>>> about what might that be anyway? >>> >>> >>> When dumping the EPROM, please dump it twice, once normal and once >>> with a >>> 1N4148 between Vcc of the EPROM and Vcc. Then compare the 2 dumps. >>> If they >>> are the same, you can consider it a successful dump. If not, the >>> dump taken >>> with the 1N4148 might be correct. >> >> I can tell my programmer to use a specific Vcc, I have to see what are >> the limits since I've never played too much with it in the past. >> Are you suggesting to use 5V and 4.3V or 6V and 5.3V? > > 5V and 4.3V. If an EPROM starts to lose data, it helps to lower Vcc. > Why becomes obvious once you understand how and EPROM cell works. > Makes sense if you think about it but it hadn't occurred to me either to lower Vcc to read a flakey EPROM. Thanks for the hint. Message was sent through the cbm-hackers mailing listReceived on 2016-10-30 22:00:22
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