Zyklus-MPS

This took a lot of tinkering and quite a bit of frustration too, but I’ve finally got Direct working with new EPROMS that I wrote myself. Going through a lot of issues with various assemblers (being on a Mac) and not knowing all the details obviously of coding ASM for Motorola which is still quite […]

Where you just can’t stop tinkering. The machine started somewhat and I did a quick check to see that the HALT line and RESET line were both ok, indicating that the CPU is in working mode. I was googleing on various 68000 related diagnostics issues when a single post caught my eye that talked about […]

A very long day of building. Today the new panel board came in, so I assembled that and the fit was perfect. I also reinstalled the powersupply in the case, along with a slight modification to make it somewhat better accesible, using some connector blocks. Also some small parts were delivered so I could finish […]

I repainted most of the case. I didn’t want to paint over the existing “direct” labels and other text, but everything else is painted. It came out ok enough, certainly a lot better than it was. To get it really good though, the whole case should have been stripped & sandblasted. Some rusty area’s really […]

While other parts of the renovation are calmly cooking, I thought I’d spend some time on actual coding. I dumped the original EPROM’s, analyzed its contents (even tried to disassemble), but they are hopelessly corrupt. No real problem, code is available so I can build new ones. I had two avenue’s to choose from. In […]

That was a really quick turnaround! Here’s the new switchboard.   I build it up with the switches, diodes, resistors and new extra long header pins.     A test fit to the front panel showed that it was nearly perfect. Only the lower row could use a nudge (less than 1 mm) up and […]

I have to replace a few components on the mainboard as well as a voltage regulator on the powersupply and some other bits & pieces. So first up is checking in detail what I need. Some of the coding on diodes etc has been worn off, so I’m using a desktop microscope to see if […]

Went to a local specialized paintsshop yesterday to have the colors scanned and mixed in machine grade paints. There will always be a color difference because the current paint is old and was subject to years of wear and stuff. But it will be better than rust. 🙂 Also included a high end primer, the […]

Thanks to Paul, who did the Zyklus boards as well, a new panel board is taking shape. I’ve been toying a bit with Kicad, but Paul is such a master in it, it takes me a day to do what he can do in a minute. With a pinch of luck, in about a week […]

Upon close inspection, the panel board suffered enough moisture damage to decide to scrap the board and create a new one. It’s not a complex board at all, thankfully. I started by removing all the switches so all the traces could be reviewed. During this process it became obvious that most switches have snuffed it […]