Hello, I'm new to this list, I've been just reading for a while. On Thu, Jul 6, 2017 at 6:14 AM, Brian White <[email protected]> wrote: > 102 is easy. 100 is not so easy. > > There was a guy in Romania selling NEC branded modules dirt cheap last year > but those are gone now. Or at least they're not on ebay any more. They > weren't labeled for model-100, I just found them by searching for the main > chip number, took a chance, and they turned out to not only fit but also > work. Maybe I should save his info before I lose track of it, in case he > does still have some. > > Maybe modules for 100 are another good candidate for an open OSH Park design > that people can build new on-demand. The basic wiring for adapting to some > more common chips is well documented. >
I've made many RAM modules replacement for the Olivetti M10 (and all the other compatibles) for some friends that asked for batches of them. Here's how one module looks like inside my M10: https://www.dropbox.com/s/iwyjg7p22c8xt5t/IMG_1484.JPG?dl=0 I've developed also a custom setup to test the modules outside the M10 (socket was getting worn out during my prototype tests): https://www.dropbox.com/s/38q01n8gckuz3of/IMG_1906.JPG?dl=0 And here's one of the batches I've made for an italian collector: https://www.dropbox.com/s/c5zes6lgevdkz2n/IMG_0266.JPG?dl=0 And here's another version of the module with slightly different logic to use different SRAM chips: https://www.dropbox.com/s/1p9tz1jgirbfaee/IMG_1601.JPG?dl=0 The test setup include different address and block tests and also a standby current measurement as these modules must not draw more than 2-4 uA during standby conditions to allow the memory battery backup last a reasonable amount of time. Most of the modules settle to much less than 1 uA standby current. A few ones went up to 1 uA. The original modules can draw up to 4 uA in standby mode. Best regards Frank IZ8DWF > -- > bkw > > On Jul 5, 2017 10:29 AM, "Jason Benson" <[email protected]> wrote: >> >> I want to fix the 8201A but I haven't had any luck yet determining the >> cause of the trouble. (see other thread about internal NiCd batteries) >> >> On Wed, Jul 5, 2017 at 10:05 AM, Josh Malone <[email protected]> >> wrote: >>> >>> What happened to the 8201A? It might be more beneficial to just repair >>> that. >>> >>> I can tell you from experience that SRAMs for the model-T are easy to >>> come by. (I recently replaced a RAM chip in my 102 w/ parts from ebay) No >>> reason to scavenge other machines for these parts. >>> >>> -Josh >>> >>> On Wed, Jul 5, 2017 at 9:19 AM, Jason Benson <[email protected]> >>> wrote: >>>> >>>> My 8201A that died the first time I tried to use it has a full set of >>>> ram expansions. Are those ram expansions usable in any of the other >>>> computers from the M100 family? I imagine the NEC PC 8300 probably uses the >>>> same chips, but probably not the M100/102. >>>> -Jason >>> >>> >> >
