I offered more than I wanted to...$200 for both computers including the two external drives. As of this morning my offer was accepted. It's now a matter of picking them up. I'll post photos of them once I have them.

Quote from: JKnightandKARR on Apr 26, 2026, 10:43 PMWall adapter is 9v@1A, so shouldn't be a problem...  lol

The great thing about a switching regulator is that there's a LOT less waste in heat when your input voltage is higher. On the LM7805, as your input voltage goes up, the regulator has to dissipate more heat to regulate.

Quote from: granz on Apr 27, 2026, 06:52 AMIs Zappman all right? This General Error on his site for over ten days, and I haven't seen any comments here, on S///C, since then. Can anyone contact him off-board to make sure that he is okay?

He logged into the forums yesterday, so it would seem he is okay. I will send him a PM. He's a valued member.

Is Zappman all right? This General Error on his site for over ten days, and I haven't seen any comments here, on S///C, since then. Can anyone contact him off-board to make sure that he is okay?

Quote from: JKnightandKARR on Apr 26, 2026, 10:43 PM

Quote from: granz on Apr 26, 2026, 12:53 PMI seem to recall that the heat sink on my Sinclair ZX-81 was pretty big, and that it had a "spring" that transferred heat to the metal paint on the inside of the case. Maybe if you put that large of a heat sink on the voltage regulator (7805 IIRC) it will keep it cool enough.

Maybe, IDK.... might have large enough heatsinks, even something from an old motherboard.

Again, if I remember correctly, the heat sink on my ZX-81 was simply a flat square of aluminum - maybe 2" by 2". That should be simple enough to make, and being flat, it fit inside the case with no trouble.

Quote from: granz on Apr 26, 2026, 12:53 PMI seem to recall that the heat sink on my Sinclair ZX-81 was pretty big, and that it had a "spring" that transferred heat to the metal paint on the inside of the case. Maybe if you put that large of a heat sink on the voltage regulator (7805 IIRC) it will keep it cool enough.

Maybe, IDK.... might have large enough heatsinks, even something from an old motherboard.

Quote from: Chris Savage on Apr 26, 2026, 03:30 PM

Quote from: JKnightandKARR on Apr 26, 2026, 12:39 PMWill find one of these to replace the 5v regulator.... the one in there gets REALLY hot, so better be safe than sorry, I'd get it on there but $6.99 + like $8.xx shipping is ridiculous....https://www.ebay.com/itm/305400148473

It's so funny you mentioning the Traco TSR 1-2450. I get mine from Digikey. They're a great replacement for the LM7805, which does dissipate a LOT of heat, since it's a linear regulator. Just be aware that the minimum input voltage is 6.5V@1A.

Wall adapter is 9v@1A, so shouldn't be a problem...  lol

Good luck Chris. I have to go to the Salvation Army Store in town more often. The only thing I ever found was a portable 7" black and white Radio Shack tv from 1970 for $3. It works perfectly with the ZX81 I have.

Cat Pen Holder



I thought this was cute in a kind of ironic way. I had to print it.

Quote from: granz on Apr 26, 2026, 10:08 AMPut in the offer, the worst that can happen is that they refuse the offer; and they might just accept. I've accept two "extremely low" offers on antique computers because I was willing to let them go for low to get them to the right person.

I had Valerie send her my "offer" earlier. We haven't yet heard back. I think she's not interested. Valerie thinks she's waiting for the sale to be over before considering it, in case they can get more. Most people out here wouldn't even have recognized either of those computers. They're so old and stored in the basement.

When I lived in CA I used to see several people from Savage///Circuits mentioning how they found a C=64 or Apple II at Goodwill or Salvation Army, and I thought to myself how I had never seen anything like that in my trips to these places. Some people are just lucky, I guess. Right place, right time.

Quote from: JKnightandKARR on Apr 26, 2026, 12:39 PMWill find one of these to replace the 5v regulator.... the one in there gets REALLY hot, so better be safe than sorry, I'd get it on there but $6.99 + like $8.xx shipping is ridiculous....https://www.ebay.com/itm/305400148473

It's so funny you mentioning the Traco TSR 1-2450. I get mine from Digikey. They're a great replacement for the LM7805, which does dissipate a LOT of heat, since it's a linear regulator. Just be aware that the minimum input voltage is 6.5V@1A.