5150/5151 Video Card??

COURYHOUSE at aol.com COURYHOUSE at aol.com
Mon Aug 15 02:45:49 CDT 2016

sad when you  think of all the  cards that have been scrapped  over the 
last  20 years  for early PC
In a message dated 8/14/2016 10:55:54 P.M. Pacific Daylight Time,  
cclist at sydex.com writes:

On  08/14/2016 10:15 PM, Fred Cisin wrote:

> why the unnecessary  switches? (CGA does mode switching in software,
> and enables  simultaneous composite and RGB, hence the IBM vetsion
> dorsn't need  switches)

I think that the switches mostly relate to output  configurations; that
is, they don't change the basic operation.  For  example, the "monochrome
composite" is probably  just luminance, blank  and sync (VBS), whereas
the "color composite" is the complete CVBS  signal.

I suspect that setting either of the two composite modes  probably
disables the output at the DE-9.

It would be interesting to  see what other combinations of switches
produce something useful.

Of  course, this is all wild-hare speculation on my part, as I don't  have
anything like this card sitting in my  hellbox.


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