Recent content by vrs42

Not really. The container I have is "Holloway House Quick Shine", but I suspect any mop-n=glo type product would do. Basically the idea is to get an acrylic polymer dilute enough to soak in, then dry onto all the nooks and crannies. It's also important not to use stuff (solvents) that would...

Sintered nylon parts are definitely very porous and prone to picking up all sorts of grime. I've had some luck soaking them in "floor finish" to create a finish that is less absorbent and easier to keep clean. Now, if JLPCB would just fix their input filters to take all correct STL files... Vince

It's Verilog, as extracted from a TTL schematic. I can send it to you if you're still interested. Vince

Possibly. However, doing that implies a learning curve for ModelSim, and presumes that I also fully understand how to model the Omnibus. My previous experience with ModelSim was that it was easy for me to get models to simulate, but hard to get models that actually ran on the hardware. I can...

There are three designs I need to debug, which all use the same board and CPLD pin-out. The serial is fairly simple, but the extended memory control uses all 64 of the CPLD pins. I'd like to get to a single setup with the cabling and the logic alanyzer programming the same for all three, since...

I've been trying to set up an HP1630G to look at the Omnibus. There's a fancy new memory/boot loader under there with a serial port implementation (the Atmel programmer's ribbon cable goes there). Boot and memory work fine, but not so much the serial port. Alas, I'm out of pods on the...

I had a DSD floppy with a DIP switch like that. It got stuck in "format a new floppy" mode and erased my boot disk (grumble). (Alas, I replaced the DIP switch a few years down the road, but now it has bit-rot in the control ROM and won't pass self-diagnostics.) Vince

I can see uses for such a thing, but I also think it's extremely handy to have all those RK05 images useable, and I can't see how you'd do both. Maybe a command line flag or the like, with the default partition sizes like the RK05? It's also imaginable to do "images" with more than two...

Alas, P?S8 isn't much like OS/8. Each system does come with a system device handler which typically supports up to 8 units. Non-system drivers are there, but there are only a couple of utilities that know how to use them, and those utilities are mostly meant for media/file format translation...

Eagle drawings, photographs of the board, etc. can be found here: https://svn.so-much-stuff.com/svn/trunk/Eagle/projects/DEC/TSC8-75/ The CPLD version is mostly a research idea, though. Vince

The late Charles Lasner used to lament that unit numbers were never implemented in OS/8. Then you'd only need a slot per driver, not a slot for every unit. (There is a mostly unused place for a unit number in the driver calling convention, but it was never used that way.) Vince

My Power supply side is missing the latches (and the power supply guard to keep your fingers out of there). Here's what I have for the cover bits. They sort of hook over the power supply, so that you have to spring the thing a bit to get it off. They are riveted bits of something that feels...

I receieved today prototype PCBs of my take on thiis. I've got a few AT1508 supposedly on the way, arriving end of week. I should be able to try something sometime next week. The board also has the 32K memory and boot loader on it. Last I checked, I can find chips for the memory section, but...

I've had several colleagues who've experienced top block failures, so I'd inspect the heck out of those, too. Bad solder, cracked traces, dirty or corroded connector pins, etc. Vince

I like it! It's reasonably easy to do, uses inexpensive replaceable parts, and seems unlikely to damage the delicate cups that the buttons press into. Vince