So this keeps coming up a few times a year, almost like people completely forget about how to use Google every now and then.
Someone has a Williams 6809 hardware game like Defender, Stargate, Joust, etc. They install a switcher instead of repairing the existing linear supply (which is OK, people have their reasons), and everything works great, except for the fact that they occasionally get CMOS corruption and lose things like settings, bookeeping, and scores.
Is something wrong with the switcher? No, something is just wrong with the CPU.
So it came to pass that I ended up with three cabinets for $100 each. A Great Golf in a Midway cabaret, some Toaplan run-n-gun in a Taito Qix cabinet, and… A Joust(!) in its original cabinet.
I agreed to purchase all three sight-unseen. When I get them all home, the golf game worked except for a rolling screen, the run-n-gun has an board issue where some sprites are being displayed at the wrong horizontal locations, and the Joust?
Well, the Joust was dead. Simple static video (monitor needs a cap kit, too), watchdog barking, no response to inputs, nothing on the LED on the ROM board.
[This was extracted from a large article about getting a dead Joust operational. I thought it made sense to put this part in its own post to help anyone else with a similar issue. This post may reference content from an earlier post, so keep that in mind when reading.]
So at this point the Joust will run through its self-tests, show 1 3 5 on the LED, and will eventually enter attract mode and can even be coined up and it will play for a few seconds before crashing again. While the screen is AFU, you can actually read text on it if you look carefully (just turn the audio off). Pay attention to how the left 1/3 screen is being drawn differently than the rest – this becomes important later:
[This was extracted from a large article about getting a dead Joust operational. I thought it made sense to put this part in its own post to help anyone else with a similar issue. It may reference content from the previous two posts here and here.]
…So now I have a Joust that boots correctly and comes up into its attract mode normally. However, after coining it up and starting a game, I still have some issues – player 1 starts running to the left non-stop!
Opening the control panel shows the switch is not stuck, and disconnecting its harness did not change the behavior, so I have another board-level issue to resolve. The input board multiplexes two sets of switches into a 6821 PIA, and the switches come in through one of two header connectors on the board.