In a previous video, I got the Apple-1 was up and running, but I still needed a usable keyboard and monitor before I could do much with it. I used an Apple II Plus keyboard as the donor, pulled from a very rough machine with heavy rust and water damage. Before I could adapt it to the Apple-1, I connected it to a working Apple II in the garage and found the usual mix of bad keys, repeating keys, and keys that didn’t respond at all.
The keyboard got a full teardown and cleaning. I pulled all the keycaps, soaked them in warm soapy water, cleaned the board and switch area with compressed air, Q-tips, and glass cleaner, then scrubbed the caps individually and left them to dry overnight. I also cleaned up some rusty screws with vinegar. Once it was back on the bench, I tried DeoxIT in the switches first, but that didn’t solve much by itself.
Checking the bad keys with a meter showed the trouble was in the switches, not the encoder. I desoldered a switch, opened it up, and found the internal leaf contacts needed to be cleaned directly. For the bad ones, I opened the switch, worked DeoxIT between the contact leaves, and exercised them until they made reliable continuity again. Some switches also needed the metal actuator bent back slightly to restore a bit more spring force. I marked the failures on a printed keyboard layout and worked through them one by one until all 16 problem switches were repaired.
The Apple II keyboard didn’t plug straight into the Apple-1, so I made a small adapter PCB to remap the signals. My first board had the header pins numbered wrong because I mixed up the symbol pin order with the IDC header layout, so I had to redesign it and wait for a corrected set. While I was waiting, I modified the keyboard encoder so the Repeat key acted as Clear Screen. That involved cutting traces near pins 19 and 20, then wiring one side to 5V and the other to pin 4 so the signal could be carried through the adapter board to the Apple-1 clear input.
When the revised boards arrived, I soldered one up and checked the pinout carefully with a meter before connecting anything valuable. I verified the power rails first, including +5V, -12V, and ground, then checked the rest of the mapping. With the keyboard connected to the Apple-1, the Repeat key cleared the screen, Reset worked from the keyboard, and typing mostly worked, although I still saw a little key repeat on a few keys.
For the display, I used a Sanyo VM-4512 monitor. At first it looked dead, but after letting it sit on a bit longer I got a raster, and then I was able to feed it a signal. The picture was sharp, but the front panel controls were scratchy and the image skewed as more characters were typed across the screen. The Apple-1 worked normally on an Apple IIc monitor and on a widescreen TV, and an Apple II also displayed fine on the Sanyo, so I went back to the Apple-1 video output.
I added a simple video mod to the bottom of the Apple-1 using a capacitor, transistor, and a few resistors. That improved the display, and after some further troubleshooting I removed a couple of resistors from that mod arrangement, which cleared up the problem on this monitor. I also replaced two oversized Sprague capacitors with more period-looking parts and swapped in a more appropriate heatsink. Then I opened the monitor, cleaned the front panel potentiometers with DeoxIT through the openings in the controls, and worked them until the brightness and contrast adjustments behaved normally again.
By the end, the Apple-1 was running with the repaired Apple II Plus keyboard and the Sanyo monitor, and I spent some time typing in programs and testing loading over the cassette interface.
— Aaron
Links
Timestamps
00:00 – Intro
00:51 – Keyboard
04:43 – Key Switches
08:06 – Keyboard Mods
18:35 – Monitor
25:12 – Video Mod And Repair
30:45 – Wrap Up