pjh@mccc.UUCP (Pete Holsberg) (04/21/89)
A friend would like to be able to run CGA graphics programs on his monochrome
PC by adding a CGA board to the system. Is it possible to do this? Can a
monochrome monitor handle both monochrome and RGB signals? How?
If he needs a CGA monitor, how is the switching between mono and CGA
implemented?
Thanks,
Pete
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In article <680@mccc.UUCP>, pjh@mccc.UUCP (Pete Holsberg) writes: > A friend would like to be able to run CGA graphics programs on his monochrome > PC by adding a CGA board to the system. Is it possible to do this? Can a > monochrome monitor handle both monochrome and RGB signals? How? For at least the vast majority of PCs, this is pretty easy. (There may be a FEW odd models out there whose BIOS is unable to handle this sort of thing, but I've never encountered any). All you have to do is to put in both the cards. There are no conflicts on either of the cards with other common non-video cards. (NOTE: It is not possible to mix Hercules with monochrome [why would you want to, anyway?], nor is it possible to mix EGA in a monochrome mode with a monochrome or a Hercules adapter [again, why would you want to?], and VGA doesn't mix well with other adapters. Other than this, you can pretty much mix-and-match: EGA with mono, CGA with mono, EGA with Hercules, CGA with Hercules. In fact, I'm writing this on a PC which has an EGA and a Hercules monochrome card). You will have to use the DIP switches on the motherboard to select the default display adapter -- if you want to keep the monochrome as the default display, you don't have to do anything. Switching between the two displays is quite easy: Just issue a "MODE CO80" to go to the CGA monitor, and "MODE MONO" to go to the monochrome monitor. Monochrome monitors can't handle RGB-type signals unless they are multisync-type monitors (a little odd for a monochrome monitor, but they do exist). It is possible to convert RGB to a monochrome signal, but if you don't know how to do this you probably shouldn't try - you can destroy the monitor and/or the adapter if you get it wrong. By the way, if all you are interested in is monochrome graphics, and aren't very interested in the color modes of the CGA, you will probably find that a Hercules monochrome card will be a better solution - you get MUCH better resolution than with a CGA, and save the cost of a color monitor. To install this you would just remove the old monochrome adapter and put in the Hercules. There is software to allow many programs to use the Hercules modes (including BASIC). Good luck. Bruce C. Wright
dalew@casper.UUCP (Dale Weber) (04/24/89)
In an article of <20 Apr 89 21:14:42 GMT>, pjh@mccc.UUCP (Pete Holsberg) writes:
->A friend would like to be able to run CGA graphics programs on his
->monochrome PC by adding a CGA board to the system. Is it possible to do
->this? Can a monochrome monitor handle both monochrome and RGB signals?
Yes, you can a lot of the software, including many games that require CGA
if you use an emulator like HGCIBM. This is the one I use when I need to
emulate CGA on my Hercules compatible display system.
->If he needs a CGA monitor, how is the switching between mono and CGA
->implemented?
It's not done in hardware unless you have a special EGA or VGA adapter
that allows emulation of CGA on a monochrome monitor. I will just stick to
using HGCIBM until I can afford to step up to VGA color. The software
emulation works very well in most cases, if a bit slow at times.
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