> it absolutely boggles the mind that an HDMI output for this thing would be taken care of by an RPi

There's a much much easier way:

https://www.bytedelight.com/?product_cat=videoaudio

The HDMI licence costs quite a lot. It's much cheaper for small runs to use a device with one onboard, and let it emit the very expensive signals.

Don't just plug them in randomly! The original power brick can get out of spec (delivering over-voltage), and the voltage regulator on the PCB commonly fails. In the worst case this can end up permanently damaging other components. There's a routine you can follow to test each part, although you'll need a multimeter and some experience, and a bench power supply will come in handy as well.

I'd recommend looking at these sites: https://retrorepairsandrefurbs.com/sinclair-computers/ https://www.retroleum.co.uk/

and Lee on Youtube: https://www.youtube.com/@MoreFunMakingIt/videos https://www.youtube.com/@morefunfixingit/videos plus Lee has a Discord where they discuss fixing old Sinclairs, linked here: https://www.morefunmakingit.co.uk/links/.

This one? https://loadzx.com/en/

If yes, they will be in very good hands.

Donate it. What use is it sitting in storage forever, unused?

Not necessarily, the higher rated packages are rated higher because they use higher quality materials that have a lower thermal coefficient (for getting the heat out), so yes the energy in Watts is the same but they’ll still probably run cooler.

If you’re interested whether this is the case you’d look for a thing called “junction thermal coefficient” on the data sheet.

Are there not 7805 replacements which internally are switch mode? (It seems almost miraculous to me that we could miniaturise a switch mode power supply into such a tiny device.)

Edit: I was thinking of: https://www.adafruit.com/product/1065

Yep, but: 2A 7805 are less likely to get damaged for the heat. The failure rate of the 7805 can be observed especially in the Commodore 64 PSUs.

Good point. I should know this.

The later real Sinclair ones like the QL. Rick Dickinson, who did these designs, was responsible for designing the recent Kickstarted ZX Spectrum Next, which is a lovely machine.

Absolutely. I have lots of fun restoring old machines; it's one of my favourite hobbies. Not only do I get a nostalgia kick from remembering systems from my younger years, but I also learn a great deal about how they worked internally and about electronics. Once they're fixed, I lose interest and move to the next project.

I still have mine, although it was my 2nd Spectrum.

I am still sad and annoyed that Sinclair Research took the technologically very conservative design from Investronica in Spain, and not the older, existing, and more ambitious design from Timex in the USA for the Timex-Sinclair 2068.

The Investronica 128 had an industry-standard sound chip, and used its I/O ports for some fairly pointless extras, like MIDI, RS232 and a numeric keypad. I have a keypad for mine, but nobody cared. It also had extra RAM and that's about it.

The American machine had the same sound chip, a ROM cartridge slot, 2 joystick ports (so, equivalent to a built-in Sinclair Interface 2), and also 2 better graphics modes, and could page out the ROM for CP/M. The same paging mechanism allowed more RAM just like the Spanish machine.

The joystick ports were far more worthwhile than a numeric keypad or a serial port.

Amstrad later copied the joystick ports, and later still CP/M, but nothing else.

:) Centro Comercial Fonte Nova em Lisboa.