Zyklus-MPS

A lot has been happening. Since the hardware restoration was pretty much done, it was time to start focusing on getting the OS to work. There were quite a few hurdles to take. These were the options so far: Use the MCL68+ CPU emulator.  This wouldn’t work out of the box, for the simple reason […]

Have a few days off for the holidays which allows me to get some of the more tedious work done. I mapped out the complete MIDI EDAC connector to the main board. It includes signals for an RS232 port and two foot switches. I also rebuild the Metronome level pot. It was jerry-rigged with a […]

Here’s some imagery of where it is at now. Focus for the next few weeks will be on refurbishing the audio section, creating the MIDI breakout box, which includes tracing all the midi connections to the mainboard and further and mapping these out in the EDAC connector. And finally, we’re mapping out the IDC40 connector […]

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 […]