#c1581

In this week's episode of Why Doesn't The Bloody Thing Work we'll take a look at this thing I just threw together on a whim from parts I had lying around. Well, TBH I had planned to build it sooner or later - it's the 1581 enhanced, a floppy disk drive for Commodore 8-bit machines using the 3.5 inch floppys we all know and love. What makes it special is that it can use normal wall wart for power, it doesn't need that special Commodore PSU with a DIN plug. The drive mech is a modified PC drive, and the case is 3D printed. I'm troubleshooting the freshly soldered mainboard here. Turns there was three reasons for it's nonfunctional state. #commodore #c1581 #retrocomputing

#commodore #c1581 #retrocomputing Reason number one was that it needs a ROM chip with the right stuff on it. In my befuddeled state I burned the EPROM, put it aside and made a label for it - and then grabbed another random EPROM lying around on my desk, put on the label on that one and tried using it. No luck with that. Turns out I had tried to use this hilariously fake 27c128 (or is that what it is?) - it's blank and the wrong kind. Took me an hour or so to figure that one out. I need to clean up my messy desk, I guess.

#commodore #c1581 #retrocomputing The next reason was not on me: The drive powered up all right, but when it was connected to my C128, I would never get a blinking cursor after the READY promt on the computer. It would simply hang. The C128 checks for a bootable disk when it starts, seemed like something failed during that process. After a bit of experimenting I found that the 74LS14s from this batch was the issue. All of them causes the same error. A desoldered 74LS14 from a scrap board fixed the issue right away. The funny thing is that these 74LS14s passes the logic IC test in my MiniPro. So it seems that they are 7414s of some kind, but I guess they're not LS parts...I think Noel from Noels Retro Lab on YouTube had a similiar issue with a logic chp in one of his videos. Seriously, what's the point of faking stuff like this?