MaxSpeed VGA MaxStation

John Ames commodorejohn at gmail.com
Wed Mar 24 22:41:12 CDT 2021


So, some months ago, I was in an electronics surplus store and picked
up what was obviously an X terminal - tiny metal slab with a VGA
connector, serial & parallel, AT keyboard, and RJ45 "communication"
port. I got it bare, without the external PSU that would've gone with
it, and I've since been unable to determine just what the heck I'm
supposed to feed this thing. It's a standard barrel jack, but there's
no markings on the case or the PCB to give any clue as to what
voltage/amperage or polarity it expects, and Google has been no help
at all. Does anyone have any recollection of these things? Any idea
what they want for juice?

To throw an extra mysterious wrinkle into this, when I popped open the
case to get a look at the PCB, I found that, apart from the CPU, DART,
and ROM, the only non-glue ICs on the board were an 8K SRAM and a
W82C476 RAMDAC - but 8K isn't even remotely enough for a VGA screen,
not even a monochrome one at VGA resolution! Am I missing something on
how these things operated? Given this, my only guess would be some
kind of insane networked-framebuffer scheme where the host would blast
video data in on the fly, but there's no way this was even 100Mbps
Ethernet, and 10Mbps isn't nearly fast enough to transfer 150KB at
60FPS, and there's no memory to buffer it for a slower refresh. What
in the heck is going on here?


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