⚳ rapid unscheduled assembly ⚳

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/* five errata and a couple of appnotes in a trenchcoat
* profile picture generated by a machine, I do not look exactly like this
* very queer
* permanently attached to @abbynormative and she can't get rid of me
* firmware hax, filks and bikes of various kinds
* abuse of very, very old computers a speciality
* creative photon abuse 30mm - 5mm, 700nm - 350nm
*/
pronounsthat's classified
locationeither SVC mode or EL3 depending on how wide I'm feeling
wat do?code and technical melting
Show thread⚳ rapid unscheduled assembly ⚳Dec 10
I was curious so
⚳ rapid unscheduled assembly ⚳Dec 10
so I saw this
Show thread⚳ rapid unscheduled assembly ⚳Mar 17, 2024
In case you're interested, here's the pinout for the AMS40464 as used in the Amstrad 6128 Plus, 464 Plus and GX4000. (They're all the same machine, really.)
Show thread⚳ rapid unscheduled assembly ⚳Mar 17, 2024

Okay, one last one. Mode 0 has never looked so good!

This turned out to be a bit involved; the Plus has a 12-bit video DAC which looks to be a custom part (and also, not very good). I figured out what the pinout was and attached to its pins from underneath; I extracted CSYNC from the eastern end of R87.

The Retrotink 2X SCART did its best, but this is clearly better in every respect. As of course it ought to be, given that I'm pulling the digital pixel data out of the DAC directly.

Show thread⚳ rapid unscheduled assembly ⚳Mar 17, 2024
It's so crispy!
Show thread⚳ rapid unscheduled assembly ⚳Mar 17, 2024
Oh yeah, also it seems to work with most demoscene CRTC hax. The Batman Forever demo uses overscan throughout, and seems to be fine. The Plus jail bars are gone too, of course.
Show thread⚳ rapid unscheduled assembly ⚳Mar 17, 2024
I managed to find space to fit it inside.
⚳ rapid unscheduled assembly ⚳Mar 17, 2024
I regret to inform you that I am back on my bullshit.
⚳ rapid unscheduled assembly ⚳Feb 17, 2024
My wife is so hot.
Show thread⚳ rapid unscheduled assembly ⚳Feb 11, 2024

So let's go back to the video output circuitry, because it's super weird. The only video output it has is TTL-level, PAL-resolution, RGBI. And the I isn't working right now. There are a total of zero monitors that will accept this, except maybe whatever Commodore Germany shipped with their C128s. I guarantee that Amstrad did not plan on selling those with this thing.

And then the video electronics are just kind of weird.