There are at least a few different "build your own ram upgrade" articles on club100 and other archives of old forum posts, and in magazines too I think but those are hard to search.
Here's one that is not one of the old original ones I was thinking of, but looks ok. http://digilander.libero.it/rar2k/TRS80/Memory24k.html I have some NEC modules that work that I assume must have originally been meant for nec 8201a. They are a little pcb with a single ram chip and an additional chip probably a decoder of some sort to consume 4 chip-enable lines. I could take some photos of it and maybe it's circuit could be reverse engineered from that. https://photos.app.goo.gl/ZQle2id7AMWdX2bC3 Another option is QUAD, which is a thing that installs in the bus socket and displaces the internal ram with it's own full 32K, plus 3 more banks of 32K that you can switch between. Although you can't get a quad right now. Steven Adolph is testing his latest revision of the design and it's in between right now. He found problems with the old version and so removed it from oshpark, and th new version is not yet verified. But assuming that comes along sooner or later, that would upgrade you to 32K the same as if you had installed all 4 possible modules inside. -- bkw On Wed, Mar 14, 2018, 11:14 AM Gregory McGill <[email protected]> wrote: > ok is there a source for the 100 chips? or a pcb? > > Greg > > On Wed, Mar 14, 2018 at 12:02 AM, Fugu ME100 <[email protected]> wrote: > >> Just the 102, it uses a standard pin out. The 100 uses a special RAM >> module. >> >> From: M100 <[email protected]> on behalf of Gregory >> McGill <[email protected]> >> Reply-To: <[email protected]> >> Date: Tuesday, March 13, 2018 at 10:58 PM >> To: <[email protected]> >> Subject: Re: [M100] 8K RAM Chip >> >> oh wait these are 32x8 :) are these ones on ebay for the 100 or 102? or >> both? >> >> Greg >> >> On Fri, Mar 9, 2018 at 7:33 PM, Gregory McGill <[email protected]> >> wrote: >> >>> if you have the pinouts I have a bunch of 8x8 srams around for TI99 >>> projects >>> >>> Greg >>> >>> On Fri, Mar 9, 2018 at 6:11 PM, Ken Pettit <[email protected]> wrote: >>> >>>> Ahh, I see now the original email stated 102. So yeah, those will work. >>>> >>>> Ken >>>> >>>> >>>> On 3/9/18 6:09 PM, Fugu ME100 wrote: >>>> >>>>> More if it was R/S :) >>>>> >>>>> This is the one >>>>> >>>>> https://www.ebay.com/itm/1-TOSHIBA-TC5565PL-15-64K-8Kx8-SRAM-CMOS-STATIC-RA >>>>> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ebay.com%2Fitm%2F1-TOSHIBA-TC5565PL-15-64K-8Kx8-SRAM-CMOS-STATIC-RA&data=02%7C01%7C%7C96a3aaaefa374c53deac08d58970ab2a%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636566039350646620&sdata=TK1b2KzBAUixcShsDPDAlwUiZAgII%2BTVKFPFUHY9Qww%3D&reserved=0> >>>>> >>>>> M-5V-150NS-28-PIN-PDIP/321974484773?hash=item4af72cbf25:g:ldEAAOSwGotWlWd9 >>>>> you mean? >>>>> >>>>> >>>>> >>>>> On 9/3/18, 6:07 PM, "M100 on behalf of Peter Vollan" >>>>> <[email protected] on behalf of [email protected]> >>>>> wrote: >>>>> >>>>> Wow, a quick check reveals a 8kX8 SRAM on ebay for $3. Didn't those >>>>>> "memory modules" cost about $30? >>>>>> >>>>>> >>>>>> On 9 March 2018 at 17:57, Chris Kmiec <[email protected]> wrote: >>>>>> >>>>>>> Great, I'll go looking on the intrawebs :) >>>>>>> >>>>>>> You don't happen to have another REX, do you? :) >>>>>>> >>>>>>> Chris >>>>>>> >>>>>>> On Fri, Mar 9, 2018 at 7:01 PM, Fugu ME100 <[email protected]> >>>>>>> wrote: >>>>>>> >>>>>>>> The chips are available they are standard 8Kx8 SRAM. Should be >>>>>>>> able to >>>>>>>> find some on line. >>>>>>>> >>>>>>>> Unfortunately the QUAD is only for the Model 100, it will not fit >>>>>>>> the >>>>>>>> 102. >>>>>>>> >>>>>>>> Congratulations on your new addition :) >>>>>>>> >>>>>>>> From: M100 <[email protected]> on behalf of Chris >>>>>>>> Kmiec >>>>>>>> <[email protected]> >>>>>>>> Reply-To: <[email protected]> >>>>>>>> Date: Friday, March 9, 2018 at 4:33 PM >>>>>>>> To: <[email protected]> >>>>>>>> Subject: [M100] 8K RAM Chip >>>>>>>> >>>>>>>> Are these available anywhere, or do I have to find a donor system? >>>>>>>> Just >>>>>>>> got a like-new 102, but no memory expansion. >>>>>>>> >>>>>>>> I'm assuming QUAD is no longer being made/sold? >>>>>>>> >>>>>>>> Thanks! >>>>>>>> >>>>>>> >>>>>>> >>>>> >>>> >>> >> > On Mar 14, 2018 11:14 AM, "Gregory McGill" <[email protected]> wrote: ok is there a source for the 100 chips? or a pcb? Greg On Wed, Mar 14, 2018 at 12:02 AM, Fugu ME100 <[email protected]> wrote: > Just the 102, it uses a standard pin out. The 100 uses a special RAM > module. > > From: M100 <[email protected]> on behalf of Gregory > McGill <[email protected]> > Reply-To: <[email protected]> > Date: Tuesday, March 13, 2018 at 10:58 PM > To: <[email protected]> > Subject: Re: [M100] 8K RAM Chip > > oh wait these are 32x8 :) are these ones on ebay for the 100 or 102? or > both? > > Greg > > On Fri, Mar 9, 2018 at 7:33 PM, Gregory McGill <[email protected]> > wrote: > >> if you have the pinouts I have a bunch of 8x8 srams around for TI99 >> projects >> >> Greg >> >> On Fri, Mar 9, 2018 at 6:11 PM, Ken Pettit <[email protected]> wrote: >> >>> Ahh, I see now the original email stated 102. So yeah, those will work. >>> >>> Ken >>> >>> >>> On 3/9/18 6:09 PM, Fugu ME100 wrote: >>> >>>> More if it was R/S :) >>>> >>>> This is the one >>>> >>>> https://www.ebay.com/itm/1-TOSHIBA-TC5565PL-15-64K-8Kx8-SRAM-CMOS-STATIC-RA >>>> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ebay.com%2Fitm%2F1-TOSHIBA-TC5565PL-15-64K-8Kx8-SRAM-CMOS-STATIC-RA&data=02%7C01%7C%7C96a3aaaefa374c53deac08d58970ab2a%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636566039350646620&sdata=TK1b2KzBAUixcShsDPDAlwUiZAgII%2BTVKFPFUHY9Qww%3D&reserved=0> >>>> >>>> M-5V-150NS-28-PIN-PDIP/321974484773?hash=item4af72cbf25:g:ldEAAOSwGotWlWd9 >>>> you mean? >>>> >>>> >>>> >>>> On 9/3/18, 6:07 PM, "M100 on behalf of Peter Vollan" >>>> <[email protected] on behalf of [email protected]> >>>> wrote: >>>> >>>> Wow, a quick check reveals a 8kX8 SRAM on ebay for $3. Didn't those >>>>> "memory modules" cost about $30? >>>>> >>>>> >>>>> On 9 March 2018 at 17:57, Chris Kmiec <[email protected]> wrote: >>>>> >>>>>> Great, I'll go looking on the intrawebs :) >>>>>> >>>>>> You don't happen to have another REX, do you? :) >>>>>> >>>>>> Chris >>>>>> >>>>>> On Fri, Mar 9, 2018 at 7:01 PM, Fugu ME100 <[email protected]> >>>>>> wrote: >>>>>> >>>>>>> The chips are available they are standard 8Kx8 SRAM. Should be able >>>>>>> to >>>>>>> find some on line. >>>>>>> >>>>>>> Unfortunately the QUAD is only for the Model 100, it will not fit the >>>>>>> 102. >>>>>>> >>>>>>> Congratulations on your new addition :) >>>>>>> >>>>>>> From: M100 <[email protected]> on behalf of Chris >>>>>>> Kmiec >>>>>>> <[email protected]> >>>>>>> Reply-To: <[email protected]> >>>>>>> Date: Friday, March 9, 2018 at 4:33 PM >>>>>>> To: <[email protected]> >>>>>>> Subject: [M100] 8K RAM Chip >>>>>>> >>>>>>> Are these available anywhere, or do I have to find a donor system? >>>>>>> Just >>>>>>> got a like-new 102, but no memory expansion. >>>>>>> >>>>>>> I'm assuming QUAD is no longer being made/sold? >>>>>>> >>>>>>> Thanks! >>>>>>> >>>>>> >>>>>> >>>> >>> >> >
