Artemis Mog 🌸 @[email protected]

Paper, rotated image

Today I got a spam text message addressed to my deadname. I just wrote back, "Sorry, wrong number, there's no one by that name here!"

I also may have fried my SID chip 😬 I'd removed it to do some troubleshooting related to that weird mod, and I accidentally replaced it backwards and powered on the machine before I'd noticed. Won't know for sure if it's dead or not until I get the machine booting though. Really hope it's okay, but I'm definitely not holding my breath…

Okay, some updates after a few more nights working on the C128:

The suspicious logic chip was actually fine; I just had a bad connection on the scope probe.

I decided to finally take the bottom shield off the board and found a really weird mod: a 68 Ω resistor between the 1 MHz clock and the output of a NAND gate. It was preventing the output signals from reaching full TTL level. I removed it, which fixed that. The data bus is still tied up, though, so something else is still going on.

(Very much hoping I'm correct, because you can still get new modern replacements for these discrete logic chips. Just about everything else on the board, not so much!)

Okay, it looks like the Z80 is not resetting the bus properly for some reason. I'm suspicious of a particular logic chip, but I need to test some more to verify.

Not right now though, it is _entirely_ too late! I'm going home.

Aha! From the service manual it looks like this is the intended behaviour for an I/O operation. A bit more poking around confirms that the computer appears to be stuck in some sort of I/O operation. Very interesting.

Oscilloscope get! And I think I may have found my problem.

This is supposed to be a 2 MHz clock. As you can see, it, ah, isn't.

Service manual says this means there's one of three chips that could be bad, but I don't buy it. Perfectly halving the clock signal would be a really weird failure mode. I think there must be something else going on, and that this is just a red herring.

Okay. All chips removed, voltage regulator tested good, chips replaced. Plugging it into the TV, I'm getting a signal out, but it's just a blank screen. So the rest of this adventure may have to wait until I can get it to an oscilloscope to check that it's functioning properly.

The solder blob was on one of the screw holes. I guess the previous owner lost a screw!

. @[email protected] joins the party so that I can borrow her soldering iron to remove the RF shield/heat sync! There's a big blob of solder on one side holding it to the mainboard for some reason

Decided to test the voltages again anyway before I actually cracked the power supply all the way open though, and I'm actually getting fine readings now??? So I guess I'll power up the computer and see if it works!

Gonna open it up first though to pull out the important chips (if they're socketed) and test the voltage regulators.

The power supply had these annoying screw covers preventing me from getting into it. I didn't have much luck trying to pry them out with a screwdriver, so I just drilled them out! Worked like a charm

I got the computer and disk drive for $10 total about ten years ago at my church at the time's rummage sale. This was before retro YouTube had taken off, of course.

Last time I tried to use it a few years ago, I couldn't get it to power on and read no voltages on the power supply outputs, so I'll probably have some repair work to do.

Parents brought up my Commodore 128 that was in storage at their house today :D

(Excuse the mess haha)

Time for another project thread!

I think I dreamt that we started daylight savings time last night, and I went most of the morning thinking that was true before finally realizing that it didn't make any sense…

I think this is the first place my name has been used anywhere "official," and it's a really really good feeling

Got my name updated on the band roster :D

I didn't even have to talk to anyone, I just meticulously corrected every roll sheet that I signed until they changed it. Persistence pays off :P

The result of a conversation with my roommate tonight

Got some cinnamon rolls from the bakery yesterday…ngl they were a big motivating factor in getting me out of bed this morning lol