kirchner@uklirb.UUCP (Reinhard Kirchner) (05/12/89)
Hello,
recently an interesting question arised, for which I could not find
an answer in the magazines or in any book. The problem:
How can a monochrome monitor be used at a colour adapter ?
and the rationale behind: How to run programs which insist on CGA, EGA, VGA-
colour if you only can afford a mono-monitor.
Till now I see the following possibilities:
1. Buy or build some kind of 'three-colour-output-to-one-video-input-converter'
which should consist of some resistors and which transforms the colour
signals to a shade of grays. If the monitors syncs this could work.
2. Use the mono-monitor at a hercules adapter and convert by software.
I have seen such converters for CGA->hercules, but not for EGA or VGA.
Are those existing or for some ( which ) reason impossible?
3. Some intelligent graphic adapter could do the conversion by itself.
I know that VGA-adapters my drive mono-monitors, but
- does this work even if the software uses a colour mode or must the
software use the VGA-mono-mode ?
Is there any adapter known which does the conversion for CGA and EGA ?
This topic may be of interest for many readers, so please send your opinions
to this newsgroup.
Thanks to anybody who is going to respond.
R. Kirchner
Univ. of Kaiserslautern, Germanyvail@tegra.UUCP (Johnathan Vail) (05/15/89)
In article <5003@uklirb.UUCP> kirchner@uklirb.UUCP (Reinhard Kirchner) writes: How can a monochrome monitor be used at a colour adapter ? and the rationale behind: How to run programs which insist on CGA, EGA, VGA- colour if you only can afford a mono-monitor. Till now I see the following possibilities: 1. Buy or build some kind of 'three-colour-output-to-one-video-input-converter' which should consist of some resistors and which transforms the colour signals to a shade of grays. If the monitors syncs this could work. Syncing is the easy part. The cheap "mono" monitors are TTL. That means that the video signal is either on or off (yes, there is the intense signal that gives you on, intense or off). Getting one of these to do shades would be difficult. Monitors that are designed for shades are almost as much a color monitors. 2. Use the mono-monitor at a hercules adapter and convert by software. I have seen such converters for CGA->hercules, but not for EGA or VGA. Are those existing or for some ( which ) reason impossible? CGA emulation is slow and will suffer compatibility problems. Impossible for EGA/VGA since the memory is not directly accessible but fiddled with different hardware registers. These cannot be emulated in software. 3. Some intelligent graphic adapter could do the conversion by itself. I know that VGA-adapters my drive mono-monitors, but - does this work even if the software uses a colour mode or must the software use the VGA-mono-mode ? Unknown. Maybe someone else knows. Is there any adapter known which does the conversion for CGA and EGA ? R. Kirchner Univ. of Kaiserslautern, Germany I would suggest the Zenith mono-EGA. It can do 16 shades with an EGA card for about half the price of a color monitor. "Do policemen dream? ..Yes when they're fast asleep. And when policemen dream? ..It proves they're fast asleep" -- Robyn Hitchcock _____ | | Johnathan Vail | tegra!N1DXG@ulowell.edu |Tegra| (508) 663-7435 | N1DXG@145.110-,145.270-,444.2+,448.625- -----
lfk@mbio.med.upenn.edu (Lee Kolakowski) (05/16/89)
In article <503@atlas.tegra.UUCP> vail@tegra.UUCP (Johnathan Vail) writes: Path: netnews.upenn.edu!rutgers!apple!bbn!ulowell!tegra!vail From: vail@tegra.UUCP (Johnathan Vail) Newsgroups: comp.sys.ibm.pc Date: 15 May 89 15:06:39 GMT References: <5003@uklirb.UUCP> Organization: Tegra, Inc., Billerica, MA Lines: 51 In article <5003@uklirb.UUCP> kirchner@uklirb.UUCP (Reinhard Kirchner) writes: How can a monochrome monitor be used at a colour adapter ? and the rationale behind: How to run programs which insist on CGA, EGA, VGA- colour if you only can afford a mono-monitor. Till now I see the following possibilities: 1. Buy or build some kind of 'three-colour-output-to-one-video-input-converter' which should consist of some resistors and which transforms the colour signals to a shade of grays. If the monitors syncs this could work. Syncing is the easy part. The cheap "mono" monitors are TTL. That means that the video signal is either on or off (yes, there is the intense signal that gives you on, intense or off). Getting one of these to do shades would be difficult. Monitors that are designed for shades are almost as much a color monitors. 2. Use the mono-monitor at a hercules adapter and convert by software. I have seen such converters for CGA->hercules, but not for EGA or VGA. Are those existing or for some ( which ) reason impossible? CGA emulation is slow and will suffer compatibility problems. Impossible for EGA/VGA since the memory is not directly accessible but fiddled with different hardware registers. These cannot be emulated in software. 3. Some intelligent graphic adapter could do the conversion by itself. I know that VGA-adapters my drive mono-monitors, but - does this work even if the software uses a colour mode or must the software use the VGA-mono-mode ? Unknown. Maybe someone else knows. Is there any adapter known which does the conversion for CGA and EGA ? R. Kirchner Univ. of Kaiserslautern, Germany I would suggest the Zenith mono-EGA. It can do 16 shades with an EGA card for about half the price of a color monitor. "Do policemen dream? ..Yes when they're fast asleep. And when policemen dream? ..It proves they're fast asleep" -- Robyn Hitchcock _____ | | Johnathan Vail | tegra!N1DXG@ulowell.edu |Tegra| (508) 663-7435 | N1DXG@145.110-,145.270-,444.2+,448.625- ----- -- Frank Kolakowski ===================================================================== |lfk@mbio.med.upenn.edu || Lee F. Kolakowski | |kolakowski@mscf.med.upenn. || Univ. of Penna. | |c/o jes@eniac.seas.upenn.edu || Dept of Chemistry | |kolakowski@c.chem.upenn.edu || 231 South 34th St. | |bcooperman.kolakowski@bionet-20.arpa || Phila, PA 19104 | |AT&T: 1-215-898-2927 ||--------------------------| |#include <litigate.h> || One-Liner Here! | =====================================================================
lfk@mbio.med.upenn.edu (Lee Kolakowski) (05/16/89)
Sorry for the previous article, I slipped and our news interface can't cancel! In article <503@atlas.tegra.UUCP> vail@tegra.UUCP (Johnathan Vail) writes: In article <5003@uklirb.UUCP> kirchner@uklirb.UUCP (Reinhard Kirchner) writes: How can a monochrome monitor be used at a colour adapter ? [...stuff deleted] Unknown. Maybe someone else knows. Is there any adapter known which does the conversion for CGA and EGA ? Paradise (a division of Western Digital) makes at least two video cards which will do what you want. The first Paradise Modular Graphics Card is old technology and did CGA/MGA with 16 shades on a mono monitor. The newer card is the Paradise AutoSwitch Monchrome EGA (I have this card and had the MG Card, if needed I'll send the model no an such, just don't have it here). This card does EGA/CGA/Herc/MGA and maybe some others. It does *not* do 640X480, but in its TMM (True Mono Mode) does 43 lines X 135 chars (but does not work with fansi-console) and in the autoswitch mode does EGA 640X360 quite well. I recommend this setup. It works even better if you get a hi-res 14" Mono-monitor. #inculde "I am not affiliated with Western Digital, just a satisfied customer" P.S. There are also other cards that do the EGA emulation on a mono-monitor, and there are even some that do this with a VGA card. -- Frank Kolakowski ===================================================================== |lfk@mbio.med.upenn.edu || Lee F. Kolakowski | |kolakowski@mscf.med.upenn. || Univ. of Penna. | |c/o jes@eniac.seas.upenn.edu || Dept of Chemistry | |kolakowski@c.chem.upenn.edu || 231 South 34th St. | |bcooperman.kolakowski@bionet-20.arpa || Phila, PA 19104 | |AT&T: 1-215-898-2927 ||--------------------------| |#include <litigate.h> || One-Liner Here! | =====================================================================
mcmiller@uokmax.UUCP (Michael C Miller) (05/16/89)
> > How can a monochrome monitor be used at a colour adapter ? > 1. Buy or build some kind of 'three-colour-output-to-one-video-input-converter' > which should consist of some resistors and which transforms the colour > signals to a shade of grays. If the monitors syncs this could work. I think you should try something called a 'Grey-Scaler' (sp?). I saw this thing in a recent issue of Computer Shopper. The review was pretty favorable. It is designed to meet your exact needs so you might look in some back issues. ( sorry, mine is gone so I don't know the issue or the manufacturer ). Also I've never actually used this so I cant personally vouch for the product. As I remember, it cost only $30.00 or so . Another option you have (a quick fix but not the best ) is to wire a simple connector to send the sync and *one* of the color signals. The chosen color signal will be used to drive the vidio input of your monitor. This has worked for me in all the times I have needed it ( usually when the mono monitor is the only thing running ). I used the green vidio signal, I'm not sure why... The major drawback is that any vidio that has no green in it will not be displayed. This is bad for some games and provides no real grey scale. You will have to run things like procomm in mono mode or some of the menus will not appear when summoned. I hope this helps. BTW, I am associated in no way with the company or products mentioned above nor am I affiliated in any way with any South American cartel. bye... ...sans -- < sans => mcmiller@uokmax.UUCP or mcmiller@uokmax.ecn.uoknor.edu > < '..this one goes up to eleven. Its ONE louder.' >
abcscnge@csuna.csun.edu (Scott "The Pseudo-Hacker" Neugroschl) (05/17/89)
In article <LFK.89May15133138@mbio.med.upenn.edu> lfk@mbio.med.upenn.edu (Lee Kolakowski) writes: ]In article <503@atlas.tegra.UUCP> vail@tegra.UUCP (Johnathan Vail) writes: ] In article <5003@uklirb.UUCP> kirchner@uklirb.UUCP (Reinhard Kirchner) writes: ] How can a monochrome monitor be used at a colour adapter ? ] [deleted] ] 3. Some intelligent graphic adapter could do the conversion by itself. ] I know that VGA-adapters my drive mono-monitors, but ] - does this work even if the software uses a colour mode or must the ] software use the VGA-mono-mode ? ] ] Unknown. Maybe someone else knows. ] ] Is there any adapter known which does the conversion for CGA and EGA ? ] ] [deleted] ] I would suggest the Zenith mono-EGA. It can do 16 shades with an EGA ] card for about half the price of a color monitor. I recommend the ATI VGAWonder or ATI EGAWonder. It will interlace EGA/VGA on a colour monitor, display EGA/CGA in (dithered) grayscale on a mono monitor, and PC Mag said the the "VGA mode looked surprisingly good on a standard monochrome monitor". The EGAWonder is the same, but without VGA. These boards do extended EGA and/or VGA (800x600) too. -- Scott "The Pseudo-Hacker" Neugroschl UUCP: ...!sm.unisys.com!csun!csuna.csun.edu!abcscnge -- Beat me, Whip me, make me code in Ada -- Disclaimers? We don't need no stinking disclaimers!!!
cb@cci632.UUCP (Just another hired gun (n2hkd)) (05/18/89)
[ words about wiring... deleted ] I have hooked up CGA cards to mono monitors, However it's been a while. If you take the 3 color video signals and attach a 10K resistor to each pin on the connecter ( the values may vary to get the a better contrast ) and wire that to pin 7 ( mono video ) it should work fine. I haven't done this in a while, but AS fate would have it I need one for the week end. I'll post if the values are indeed much different... -- my signature file just got squashed...................... email: cb@cci632 or !rochester!kodak!n2hkd!curtis Curtis Braun, Computronics, PO Box 1002 Fairport NY, 14450
stephen@ziebmef.uucp (Stephen M. Dunn) (05/20/89)
In article <5003@uklirb.UUCP> kirchner@uklirb.UUCP (Reinhard Kirchner) writes:
$How can a monochrome monitor be used at a colour adapter ?
Well, there must be a very easy way, because at the university I attend,
we have room after room of IBMs and clones with mono monitors attached to
CGA cards. I don't know how it works (I have a Herc-clone in my AT-clone),
but it's probably something as simple as there being a monochrome output on
the CGA card, or a monochrome monitor just ignoring the chroma signal and
relying solely on the luma signal.
$and the rationale behind: How to run programs which insist on CGA, EGA, VGA-
$ colour if you only can afford a mono-monitor.
If you only need CGA compatibility, try getting SIMCGA (or similar) ...
many BBSs have it, and so do most of the PD/shareware distribution houses.
It looks kinda weird sometimes, but it works. What it does, in case you
don't know, is simulates a CGA on a Herc-compatible monochrome board. It
seems to be able to handle both BIOS calls and direct memory writes somehow.
$2. Use the mono-monitor at a hercules adapter and convert by software.
$ I have seen such converters for CGA->hercules, but not for EGA or VGA.
$ Are those existing or for some ( which ) reason impossible?
A full VGA simulator on a Herc would be impossible, as the VGA allows for
higher resolution than the Herc does. However, an EGA emulator should be
possible, as the Herc has better resolution than the EGA and could therefore
display EGA output. The problem is that you would have to decide which out
of the EGA's colours would appear as a dot on the screen and which would
appear as a space. This is not a problem in CGA simulation. In the CGA, you
either have four colours with 320 pixels across the screen (which can
be represented on a Herc by using two adjacent pixels for each dot, as the
resolution is more than twice this), or two colours with 640 pixels (which is
really kinda monochrome, anyway).
$3. Some intelligent graphic adapter could do the conversion by itself.
$ I know that VGA-adapters my drive mono-monitors, but
$ - does this work even if the software uses a colour mode or must the
$ software use the VGA-mono-mode ?
Well, EGA is a superset of CGA and VGA is a superset of EGA, so anything
that runs on a lower adapter will run on a higher one. Also, some VGAs
will run Herc softwaare (maybe it's part of the VGA standard; I don't know).
As for connecting them to monochrome monitors, ask a computer dealer or two.
--
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! Stephen M. Dunn stephen@ziebmef.UUCP ! DISCLAIMER: Who'd ever !
! Take off to the Great White North eh, ya hosehead ! claim such dumb ideas? !
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