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The X protocol is extensible, and evidently RandR refers to an extension. X programs can ask about or request these extensions from the display server (in this case MacX), which can either supply what the program needs (if it can) or confess that it doesn't have that capability (as seems is the...

See the section in [0] called "NON PHYSICAL FILE NAMES". The "display names" (my term, not Apple's) that you see in the Office System (which is a graphical environment that runs on top of the Lisa OS) are not the real names of files on the disk: those are all given names in curly braces like...

The advice to clean the pots on the video board is very good advice. You can still buy those pots new if that doesn't work, but I bet it will. @maceffects , I don't mean to rain on your sale, and @nickpunt , the X/ProFile is a very dependable, proven emulator worth considering. But there is a...

The PSU problem is almost surely RIFAs. Other PSU caps may be in decent shape, but recapping isn't a terrible idea. The rest of the Lisa will probably be fine --- well, the Widget hard drive probably doesn't work, but that's not the fault of the RIFAs letting go. I had never heard of a Lisa/Mac...

Signetics by the look of it. Per wikipedia:

To be fair, so will the PPC 601-powered Mac ⌛;)

Harsh! I found the post interesting, and I've never really used an Amiga or been especially interested in them. Because I am the way that I am, the various games and demos never captured my attention, and instead it's things like the fact that AmigaDOS was originally based on TRIPOS and the...

Fire up your TIFF viewer: http://www.bitsavers.org/pdf/apple/lisa/hardware/Lisa_2_10_IO_Board/ Or view well-made but reverse-engineered (so maybe less reliable) schematics at https://lisaem.sunder.net/cgi-bin/bookview2.cgi?zoom=0?page=5?book=6?Go=Go

Do the mouse and keyboard work? How are you with schematics? The Lisa boot ROM talks to the COPS through VIA 1, U7C. There is a direct connection between the two. It sounds like you've swapped all the chips there are to swap. Perhaps then look at the connections between the COPS and the VIA on...

Yes, sorry about that. As you probably found, the most recent firmware image is https://drive.google.com/file/d/1waF7hGPlwwuyyrnJ1nzStDPk1nCIjJqG/view?usp=drive_link

The parallel port inside a 2/10 runs faster than the external port on a 2/5, or something like that. (I forget the details even though I knew them fairly well at one point; only around two computers can fit in my head at the same time.) However Alex claims that experimental 2/10 support "appears...

Yes, the PocketBeagle is EOL unfortunately. It was a fun project... IDEfile is a fine and capable emulator that you build yourself. I've had one for over a decade and it works dependably. Since you have a 2/5, you can use ArduinoFile if you feel like building one. One advantage of ArduinoFile...

Fascinating, please carry out more experiments. Hold it from a different part of the board. Prop it up on something or suspend it from something (non-conductive and not statically charged) instead of holding it. Flex the board as you hold it. Press gently on connectors or ICs as you hold it or...

Shifted and repeated video suggests address bits to me. The fact that it's in large chunks suggests high-order address bits (more like A7 or A8 than A1 or A2 or whatever). At this point I'd look at schematics/read the theory of operation document and try to imagine what kind of failure could...

Do you have an oscilloscope? I would give some serious thought to getting your hands on one. Maybe a friend has one you could borrow? There are some relatively cheap options out there now. I naively give that ROM a 50% chance of fixing the issue. We know that the corruption is affected by the...

A tangent: This example isn't as contrived as you might think... The first-gen IBM 1620 computer didn't have arithmetic hardware: it kept tables for addition, subtraction, and multiplication in RAM (not ROM). The IBM development code name for the computer was "CADET", which people joked stood...

Looks like this chip is shown on the left side of the schematic here: https://www.apple3.org/Documents/Schematics/Video%20Logic.jpg When people say "video ROM" for 8-bit Apple-y machines, they are probably thinking of something like a character ROM: memory that stores the bitmap "font" data for...

That's good news about the system booting! Here's a trick you might be able to try now. The ///'s video RAM occupies two chips: 2114 SRAMs that together offer a kilobyte of memory. Are they in sockets? Try swapping them and seeing if the display changes. If the problem moves along with the...

It's good to change out old RIFAs, but they don't cause this kind of problem you see on the screen. RIFAs sit on the input ("primary") side of the power supply and help the computer be a good citizen on the power grid. A power supply has two sides, usually: the side that takes in the AC mains...

In the Portable, the keyboard and mouse are interchangeable: you can swap their locations. Each one plugs into a large header connector over a ribbon cable. Open your Portable's case (carefully!) and swap the locations of your KB and mouse and see if the problem is the same. If it isn't, then...