OK, I have the manual here. I will try to use the correct English terms, because it is the Spanish version. Anyway, I think some parts are not well translated, and there is (possibly) an important error.
Rear panel switches:
5 4 3 2 1
on off off on aie ---- EGA + CGA emulation
off on on off aie ---- EGA
off off off on aie ---- CGA
on off on off aie ---- MDA + Hercules emulation
off off on off aie ---- MDA
aie: Automatic intelligent emulation
That's what is shown in the table. But the paragraph below the table says: "Switch 5 is used to enable/disable the automatic intelligent emulation."
So, aie is set by switch 5 or switch 1??? Well, as the paragraph says, switch 5 in the table shows "on" for the 2 modes with emulation...
Some pages before, it's written "Using an additional video card, you can use simultaneously two screens, and use the rear panel video switch in the main unit to choose which screen will be activated at system boot, and which mode will they use."
But... what is the switch to choose the screen active at boot?
Putting all together, I think the paragraphs are OK, and there is a mistake on the table, 2 possibilites here:
1 - The table headers are OK, so switch 5 is aie (according to paragraph below table), and what about switch 1? It could be the switch to choose the screen.
2 - The table headers are reversed, it should show "1 2 3 4 5" instead if "5 4 3 2 1", so the table values and the paragraph below the table are OK, but there's no switch to choose screen.
Could you write your switches settings, and screen type? (to confirm one or other possibility) (I don't have the ABC here, so I can't look it now)
There's also a jumper on the mainboard related to the video: JP8, 1-2: EGA screen, 2-3: color/monochrome screen. I think it only enables or disables one of the signals in the integrated video connector.
By the way: If you are just interested in connecting a VGA screen to the integrated video (EGA) connector, it could possibly be done without installing an VGA card, just adapting the integrated connector to the screen VGA cable. I'm not sure because I'm not an expert on this matter, but if somebody is, here are the EGA connector pinouts (but please, confirm it somewhere else before trying anything!):
1 - Ground
2 - Secondary red (this is the signal controlled by JP8)
3 - Primary red
4 - Primary green
5 - Primary blue
6 - Secondary green / intensity
7 - Secondary blue / monochrome
8 - Horizontal synch
9 - Vertical synch
Edited by Rauli, Mon Jul 16, 2012 1:24 AM.