Sinclair ZX81 Spruce Up (Composite, 16K, Keyboard & More!)

Thanks to PCBWay for sponsoring this video!
Check out their KiCad Open Source Design Contest!
https://www.pcbway.com/activity/kicad...

In this video I finally get a chance to play around with the ZX81 I picked up back in September 2023 at VCFMidwest. In my younger days I may have chuckled at this thing but as I've gotten older I understand and appreciate the role this little computer had in computing history. I think for many folks this was their first computing experience just as mine was with a hand me down VIC-20.

I didn't even know if this thing worked when I bought it. Watch and see how things go!

Huge thanks to Lee from More Fun Making It! Check out his channels!
‪@MoreFunMakingIt‬
‪@morefunmakingit2‬

Resources
Wave conversion software:
https://www.zx81stuff.org.uk/zx81/tap...

Tetris (click show all files to see the .p file)
https://archive.org/details/ZX-81_Tet...

3D Monster Maze
https://www.zx81stuff.org.uk/zx81/tap...)

MP3 Player I used
https://en.wikipedia.org/wiki/Sansa_Fuze

3.5mm stereo to RCA male breakout cable similar to mine.
https://www.amazon.com/Monoprice-1006...

Ram related stuff
ZX81-Internal-16K-Expansion 'No Wobbly Edition' (project page)
https://github.com/redhawk668/ZX81-In...

The one I got from ebay is no longer listed but here is a Tindie seller link.
https://www.tindie.com/products/redha...

First 32K SOPs
https://www.ebay.com/itm/372247259274
Second 32K SOPs
https://www.ebay.com/itm/121113915913
32K DIP-28 that worked
https://www.ebay.com/itm/263959049103

Blog post with the DIP chip mod that ended up working for me.
http://blog.tynemouthsoftware.co.uk/2...

Keyboard Membrane I bought
https://www.ebay.com/itm/304989279583

Composite Mod I bought
https://www.ebay.com/itm/124844441452

As I always say, if you've not already, go check out my awesome neighbor-in-retro, ‪@retroCombs‬! He's got good stuff!

If you have actually read this far down and would like a HackShack sticker, figure out a way to get in touch with me and I'll see what I can do to get one to you! :-D

Music: ‪@WhiteBatAudio‬ Thanks for the tunes!

00:00 Intro
00:52 Surprise Special Guest!
04:42 PCBWay Spot
05:07 Initial ZX81 Testing
06:55 Replacements/Upgrades Planned
07:46 Power Supply
08:26 Open Sesame
08:50 Composite Mod
09:44 Internal 16K Upgrade
14:47 Loading Games
16:43 Keyboard Membrane Replacement
20:00 Reassembly & Final Test
21:48 Wrap-up