I know that VGA used analog signals and sync rather than digital signals.
On 6/7/2023 1:44 PM, Will Cooke via cctalk wrote:
On 06/07/2023 1:26 PM CDT Jonathan Katz via cctalk <cctalk@classiccmp.org>
wrote:
Hello!
I have an IBM 6152 aka IBM RT system I rescued. (It may be a 6151?)
I'm 90% sure it has colour graphics. The system does seem to POST
correctly (according to the LED on the front) but the CRT is dead. I'm
wondering if anyone has built an adapter to hook this to a VGA
monitor.
I'm a bit confused by the pinout. It has high and low bits for the RGB
(and associated grounds for each colour.) So I'm not sure how that
would work hooking to a more modern monitor.
http://bio.gsi.de/DOCS/IBM/615x/faqshard.html
Otherwise I need a crash course in fixing CRTs.
--
-Jon
+44 7792 149029
I am not familiar with any of that equipment, but from the description here
http://bio.gsi.de/DOCS/IBM/615x/faqshard.html#h33. it appears the video is two
bits of ttl level data for each color. That is how EGA did it, which I think
was about the same time frame (1985 ish.). The scan rates seem rather close to
EGA as well. It might be worthwhile to look into EGA interfacing.
Will
