21 Dec
2005
21 Dec
'05
5:48 a.m.
Ramdac? I The output of the CGA was plain RGBI digital, buffered
through an
LS244. There is a composite output, but it's sort of a simple-minded
resistor adder network fet to the base of a 2n3904 to so some level
shifting.
Do you have details on this resisternetwork ? i.e. is the CGA
schematic online somewhere ?
I need to add a composite output to a non-IBM CGA card and fit it
inside a IBM5155
Jos Dreesen