I've done both. One of my NEC units is a NiCd replacement and the other a super cap. My 200 is a NiCd while my 102 is a super cap. To my surprise I left my 102 without batteries for about 10 days and when I put batteries back into it the RAM was still intact. Not what I expected at all. The NiCd will definitely store data much longer but both will do. The one exception is that you cannot put a super cap into a 200. The power supply won't work right and the unit will not shut off.
Kurt On Wed, Jul 25, 2018, at 9:24 AM, Jeffrey Birt wrote: > Keep in mind that supercaps have a high self-discharge rate. From the > measurements I did when I put a 2.5F cap in my M100 I’m guessing it > would back up the full complement of RAM for about 2 days. The > original NiCad would last about a week will 4 option RAMs. That being > said I don’t see a huge problem with a 2 day backup incase the AA are > completely dead.> > Jeff > > *From:* M100 <[email protected]> *On Behalf Of *Josh > Malone *Sent:* Wednesday, July 25, 2018 11:17 AM *To:* > [email protected] *Subject:* Re: [M100] New User - Resurrected T102> > Welcome to the club! Congratulations and Thanks on/for restoring a > M102. I have a 102 as my "daily driver" and hope to also repair a > couple of problematic 100s in the near future. Thanks, also, for the > part numbers. I'm debating cap-vs-nimh for my restores. My recent > experience with a capped 100 is leaning me in that direction.> > -Josh > > On Wed, Jul 25, 2018 at 12:11 PM, Andy Lawrence > <[email protected]> wrote:>> Hello All, >> >> I was born in 1975, and throughout the 80s I looked forward to the >> annual Radio Shack catalogs, each year drooling over the T100/2s etc! >> Well a couple weeks ago I was cruising eBay and ran across a busted >> T102 and snatched it up cheap. Completed the following to fix it up:>> >> - Restored normal functionality by re-soldering the DC jack. >> - Burned y2k ROM, thanks to GregS for pointing out the file location. >> I was planning to burn on a stash of old 27c256s, but appears I've >> used all of those, rather than eBaying surplus I simply ordered an >> AT27C256R-70PU-ND from Digikey for $1.38. This also saved me 2mA.>> - >> Swapped the leaking NiCad for a 4F Supercap, Digikey part >> 4704PHBK-ND.>> - Swapped the original 32.768k crystal for a Digikey part >> 300-8763- >> ND, which is 4PPM part, though I didn't test the original this new >> part should help keep better time.>> - Followed the 8-Bit Guy's YouTube's >> guide to "Retro Bright" the >> yellowed plastic, which turned out great aside from slightly >> damaging the Tandy T102 black plastic emblem by getting it too >> warm. :crying: Anybody have one of these laying around? I was >> utilizing a halogen lamp to warm the solution, got it too close...>> >> Though I don't have any specific plans for the T102 (right now it's >> calculating prime numbers), I've already acquired a T200, which will >> receive similar treatment!>> >> I'm really glad to see communities like this still active, brings >> back such great memories! I might even start a retro Z80/68000/etc >> or similar build, fun times ahead.>> >> Many thanks to all and have a great day. >> Andy >> >> >> >
