Brought an Arduino Leonardo a week back with thoughts of making USB Spectrum (then fitting Raspberry pi). Had been looking for non-fixable broken rubber key spectrum to use as USB keyboard for a year or so, but kept fixing broken ones (ok only 3 but now I have 4 working and no donors).
Various articles on using Spectrum keyboard to create a USB keyboard so I’ll link to those whilst doing this. Here is the main one : http://www.instructables.com/id/Convert-a-ZX82-Spectrum-keyboard-into-an-expandabl/?ALLSTEPS
Keyboard membrane connectors arrived today so I don’t need to butcher a working motherboard, or try and solder wires onto the keyboard membrane directly.
Here are the bits – the Arduino Leonardo and the 8 and 5 segment connectors. Various resistors etc from bits and pieces drawers.
Got this 1040 STe (4mb upgrade) a couple of years ago, very yellowed / discoloured.
Stripped down and removed all keys, motherboard etc. Keyboard in pieces. Then outside on the table and painted case and keys with bBlonde peroxide hair gel
Continually through the next few hours, applied recoats and moved the table (base was on a chair) to follow the sun and rotated 180 degrees every 30 minutes or so to ensure all sides were equally sun soaked. Wash off in the bath of the pieces and then back out for another hour. Keys not completed (still yellow in places) so will need another go next sunny day. Case and under keys element done.
OK, so had the Oric working fine, using scart adapter created on stripboard using schematic from here : Oric scart schematic , however after powering with 12v rather than 9v the ram chips appear to have blown, as per screen output and extremely hot ram chips (about 4 of them are suspect).
Step 1, replaced the power regulator in case this was faulty (checked with multimeter and was outputting about 4.7v – should be 5. Thermal compound. Ground soldered under PCB, need to tack a little on the top here as well. Testing – same RAM chips hot – 4.99V at the RAM though. Regulator heat sink very hot.
Have 2 C64c – 1 working, the other displaying black screen. Opened the non-working and ran for a few minutes to see if anything got hot. U9 – RAM chip very hot in short period of time. Removed the chip, socketed and replaced. Works great now. Cleaned case and keyboard.
Got two Gamecubes from ebay a few weeks ago for 10 including postage for the pair. No power supplies or controllers. Borrowed a power supply and both power on with video display (using snes composite cable). One reads discs, the other (purple one) doesn’t.
Plan is to strip them both down starting with the purple one, good clean etc. Change the power socket for a standard socket and possibly video out through rca sockets rather than the nintendo connector Power socket the main priority – nintendo composite cables are cheap to get.
Commodore pet dismantle and clean finished (with video ram replacement remaining). Next up is commodore 64c
I’ll be posting things here as I do them. Previous thing – converting Currah Micro Speech to work with composite mod spectrum.
Current project – clean and repair of a Commodore Pet 8032.