5v regulator swapped. Two main caps replaced. UHF modulator converted for Lumacode HDMI output. 16k RAM fitted internally. Ferranti ULA replaced with uLA81 chip. Keyboard replaced with Ginger Software microswitch keyboard, which has the legends for the ZXPand+ which gives the ZX81 sound, joystick and SD card functionality. This 40 year old system is set for another forty. After all this, it is only pulling 230mA, which is less than before modification, even with the ZXPand+ on the back!
See if you recognise this situation. Place an order. Get a wrong item. Have to return the item but the seller says the postage is too much and negotiates a refund for you to keep it. You thinking e-bay? Well, apparently it's now how things are done on Amazon.
When I work on a vintage machine I've never done before, I expect to make a pigs ear of it and wreck it in the course of learning. But this one somehow survived my solder butchery. Not so the case, which I bought wrongly and had to destroy the front two bolt holes in order to get the keyboard in, and then the left side panel had to be JB Welded into position because the case didn't have a retaining bar for that spacing. ZX81 with wifi, local storage, HDMI output and mechanical keyboard.
Christmas rose in snow - maybe that's how it was meant to be.
Here it is. The ZX81 with mechanical keyboard and on-board RAM pack (no more wobbles) hooked up to an RGBtoHDMI for video and a ZX-Wespi for local storage and wifi. All this pulls less than 400mA through the replacement power regulator. Sweet. Just have to finish the case and connectors now.
Work is progressing on the ZX81. The keyboard surround of the mechanical keyboard is a test of the template, in paper, before the black ABS plastic sheet arrives. The system already has on-board 16k, it has HDMI and modules are nearly here to give it internal storage and wi-fi. Yes... a ZX81 with wifi. How's that for bonkers.
Start as you mean to go on, I guess. So I've started the new year by adding extra silver buttons to four of my converted/built joysticks. The QuickShot Pro always had autofire for the trigger, but I lost it when I converted it to USB. Now, it's back, and it works for either fire button, independently, so both can be autofire at the same time :-) Start and Select are mapped to "Coin Up" and "Start 1P" so I can play MiSTer arcade games with these. The hardest part was fitting it all in the case.
The latest project is a ZX81. This is a revision 3 board from 1981. I've built the mechanical keyboard for it and have an internal 16k ram expansion (to solve the wobbly ram pack crashing issues) and the UHF module has been stripped ready for the HDMI conversion kit. The keyboard, obviously, won't fit in the case so that is a future challenge. So far all signs are that it's functioning, but the Ferranti IO chips are known for dying so once I've got the video output I shall see what it gives me.
@swetland Would it be possible to have a copy of the case files as far as you've got please? It's about time I learned to do 3d modelling.
A picture from this morning's walk. I do a short walk through the woods every workday morning (at least, when it isn't raining) and I take the camera with me.
