That's fancy, I just use my fingers

Great video - thanks for going to the trouble to post it. Those vertical bars are definitely not data line issues - that's the so-called "every other 16 pixels background" problem which manifests as a blank bar of 16 pixels every 80 pixels in mono. It's purely to do with the timing of when data is l...

Another question (which is not as easily answered): if you had an original shifter installed, would it still fail the blitter short test?

That's very interesting and strange, because the blitter doesn't interact with the shifter. And surely nothing here can tell where the mouse pointer is... right!? Unless moving the mouse to a certain spot causes the ST or its associated wires to move. Question: does it still happen when you use the ...

Adding it to EmuTOS should be relatively straightforward, without any hardware changes. ...I say "relatively" by comparison with real TOS.

I think a modified TOS would be necessary because I'm sure TOS would be checking the mono-detect pin immediately after boot to determine which video parameters it should use. It'd have to be modified to figure it out some other way. I've simply wired a physical switch into my machine that grounds th...

Woohoo! Thanks man. I love it when a plan comes together!

Very possibly!

I mean a minimally-small program that can generate scanlines shifted by each of the possible amounts. Then I can experiment with code changes and see the result. With a demo, the screen is constantly moving, so you can't keep track of what's going on - and the shifter's so busy that you can't be sur...

Unfortunately it doesn't yet work with sync-scrolling effects. I haven't worked on it yet because my 68000 programming skills aren't up to the task of making a test-case.