Search results

The photos mostly confirm my earlier post. However, I’m now thinking that the really short d-sub 9 to din 8 is an adapter that allows you to plug in Mac 128/512 cables into a Mac Plus or higher; and would not be wired as a null-modem cable.

Probably obvious; but: make sure you have an anti-static mat, wriststrap, and a good grounding point. My kit is grounded thru a built-in safety resistor (1 Megaohm - keeps you from getting badly shocked if you happen to brush up against something electrically energized) and attached to the...

Hmm… should be obvious, but if you do a GUI for class creation, it would be nice if it could be exported/imported from some text-based format like XML, or even just having it’s “native” format be a script kinda like what I suggested earlier. This would allow one to use tools like BBEdit to do...

Also; there’s pin numbering on the PCB. However, they may have flipped the header around in the PCB CAD software that they used when making the board; I’d double check with a multimeter against the pin outs to be sure.

My board doesn’t have SCSI. When the machine was in daily use way back when, we had a serial-port attached 20MB hard drive called a PCPC MacBottom (I swear, was this thing made by twelve year old boys?). Eventually, that drive died, along about the same time as the PCPC company did, so I don’t...

The other thing about HyperCard that really bugged me is that it didn't have layers or snap-to guides. Everything was on a single bitmap either on the card or the background; and getting graphics like custom buttons and frames and stuff aligned was a pain. It would be nice if editing a stack...

The thing with HyperCard is that it only allowed you to use the object classes that it had built in: cards, buttons, etc. What I was thinking is something like this: protocol MyGeometryStuff can area end MyGeometryStuff class MyBox is an object that can do MyGeometryStuff and has...

1) Yes, probably is setup as a null modem cable for connecting to PCs. 2) Likely another null modem cable. 3) Probbably a Mac 128k or 512k to Imagewriter 1 cable; or a modem cable. 4) How different? That sounds like a Plus or higher Imagewriter 1 cable. 5) Probably LocalTalk cables. Photos...

In order of probability: bad connection, short, bad or incompatible capacitor, bad trimpot, bad transistor, bad resistor, or bad inductor. Specifically I'd be looking at everything in the horizontal sweep circuit first.

I don't think that's unfixable. The pattern on the screen is an indicator of the processor either not running, or being unable to perform writes to RAM. That checkerboard pattern is what RAM chips tend to look like when power is first applied, but nothing has been written yet (one block tends...

Hmm… is the language going to have a proper class & inheritance mechanism? Also, the runtime engine is an interpreter, and not a JIT that targets only x86? In principle at least, if there’s no x86 dependencies, it should just compile for M1 processors by switching the build target to all...

I'm not sure but the lower bodge wire on the back side of the board near R84 might be going to the wrong place?

We're certain that there's no shorts on the trace rework, and no traces got missed?

The machine must initialize and access the SCSI interface chip in order to scan for a bootable system disc on the SCSI bus. Because it's freezing after that process, I'm suspicious that it's not the SCSI interface chip itself; and this is compounded by the fact that it freezes when booting from...

The other issue is that eventually, even if new flyback transformers could be sourced, the CRT itself is going to expire… in the old days (50’s, 60’s) there were companies that would re-manufacture CRTs, by cutting off the old neck, and putting a new one on. I think they also washed out the old...

Well, if the machine in question is capable of running Darwin, I suppose at least some of that information should be in the kernel source code?

Hmm… you could probably grab the pixel clock off the video output shift register with a wire lead that has a mini-grabber hook on the end. Might make capturing the video signal easier; and still wouldn’t be a permanent modification to the logic board…

Mmmm... pizza. Now I'm hungry. See what you did? 😜🍕🍕🍕

Looks like an Altera logo on the FPGA dev board? Just curious, what's your resource utilization report from the FPGA compiler say? (just trying to get a guess on how big of an FPGA would be needed for a production board). :unsure:

Eventually I think we're going to have to come up with a CRT & analog board replacement plan... perhaps a board that adapts an ATX power supply and the logic board's video output to drive a small LCD; and a 3D printable adapter & plexiglass lens to make it look kinda-sorta right. A small FPGA...