heh


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cathoderaydude
@cathoderaydude

I believe I have completely worked out the internal functioning of the video toaster, a device which nobody has ever been able to explain to me in any detail, and which should not have been able to exist at the time it did and for the price it cost. I did this by thinking about it real hard, and reading six vague sentences from its designer.

The shame is that there's absolutely nobody I could run this by for confirmation other than the guy who designed it, because anyone else who thinks they know would either be completely guessing (but incredibly certain they're right) or would be a crotchety old fuck who would be so rude about what I got wrong that I would delete his email.

anyway i'm pretty convinced it contains nothing more than an analog mixer, two framebuffers and a pair of RAMDACs, and literally everything else is done through extremely clever ways of mapping prebaked bitmaps and lookup tables into values to drive those devices.


cathoderaydude
@cathoderaydude

I'm going to be expanding on this in the (at this point 28,000 word) video I'm composing on the subject, but I just keep thinking about what I've learned and being staggered by it

the Video Toaster, an addon card for the Amiga which integrates deeply with a piece of software that runs under AmigaOS, has no ability to talk to the Amiga at all. it plugs into the machine's video slot, which is - very literally - equivalent to a VGA port, or perhaps a DVI port. there are no address or data lines. there's nothing at all except sync signals and RGB values. all commands have to be encoded into pixel data. fucking madmen.



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in reply to @cathoderaydude's post:

My guess based on the fact that it wound up being even remotely affordable is... that you are exactly correct. Does the Video Toaster have a burst sync input? Ir not, I suspect it still has genlock internally to make all the magic work.

The Panasonic WJ-MX12 I have which I think is from vaaaaaguely the same era works the same way internally, it just has a frame buffer and ramdac in line with one of the two inputs and then feeds the video split into Y and C channels into analog mixers and cmos switches

The other possibility is he is a very nice (and maybe also crotchety) old fuck (eg. my friend Dave who loves nothing more than to talk about how he designed shit in the 80s and what kind of equipment they were using and how to make a PDP-11 keep running in a steel mill etc)

in reply to @cathoderaydude's post:

Oh interesting, the doc I looked at only listed the pinout for the front half! Dang, I should have counted the pins. At any rate, I'm going off a statement by Tim Jenison (toaster designer) that the card can't talk to the CPU in any way; I'll get the link for that later

Hey, I want to thank you so much for pointing this out; I DID visit this website, but I didn't realize there was technical info here, and the doc I linked below confirms EVERYTHING. I got the whole thing right. I'm blown away. I... I have to rewrite a lot of my script now...

This just improved the quality of my video by about 50%.

I'm looking forward to the video!

With any luck, you might be able to tap those digital RGB signals off the monitor port - apparently the original plan for those was to support TTL RGB monitors like CGA/EGA did.

I 100% believe you, but I am having trouble braining together what "transitions specifically intended for porn" entail

.... but the "slime splat" program wipe from '90s Nickelodeon comes to mind, and now my entire childhood is in ruins