Jump to content
supernova777

RGB monitor

Recommended Posts

Apple Color Plus 14" Display 

Apple_Color_Plus_14_Display.png

just had a question re:using it in with a vintage PC, (im having trouble finding any old style late 1980s RGB monitors for sale)

is it an RGB/Composite type display? i know its old but im not quite sure if its EGA or VGA compatible via adapters

 

i assume it has the 15 pin connection for apple monitor

is there any adapter that i can use to attach this monitor to an EGA Wonder ATI graphics card? (9pin EGA connection on an old 386DX40 PC running DOS)

i have this 386, and this video card, and well, im trying to piece together a vintage system that has the same look/feel i remember as a 10 year old back in 1988.

 

 

just wondering if these are compatible electronically

im going to go ahead and guess YES providing i find the proper connector/adapter??????

i had one lying around for the longest time and i think it finally got pitched in the garbage 

thinking id never ever ever need it again, and now i need one ;) lol

Edited by supernova777

Share this post


Link to post
Share on other sites

For an EGA card, you really need a true EGA monitor, which has digital RGB with two intensity bits. That monitor is analog RGB, and won't support the timings an EGA monitor needs (15 and 24 kHz h-sync, 60 Hz v-sync) - it's 35 kHz h-sync, 66.7 Hz V-sync.

Share this post


Link to post
Share on other sites

Yes. For EGA you're flat out of luck for probably 99%+ of the "VGA" (IE, 15 pin plug) monitors in circulation, and a complete 100% for any monitor with an Apple label on it. That sub-1% I left out would be a few older multi-protocol "Multisync" monitors, most predominantly the NEC Multisync line, that retained the ability to do digital signaling for "a while"; I don't know exactly when they dropped support for it; I know the "Multisync 3D" could do it (and was also the first Multisync with a 15 pin VGA plug on it, earlier ones actually had a 9 pin plug and needed a special cable to do VGA) and it lasted a few years after that came out, but that only puts you into the mid-1990's. I've heard rumors that they made at least one super-premium LCD that could handle sub-VGA modes as a mostly undocumented feature but even that was 12 years ago.

Share this post


Link to post
Share on other sites

I don't think they were ever that common, honestly. EGA was really expensive when it was new and when VGA came out less than three years later the price gap between the two was pretty insignificant. In my experience it seems like most home/cost-sensitive users jumped straight from CGA to VGA.

 

Honestly, if what you have there is a 386/40 I'd say you'd be justified in swapping the EGA card for a VGA. An ISA VGA card is going to be easier to find than an EGA monitor, and considering the am386 didn't come out until 1991 it's actually probably a better fit chronologically.

Share this post


Link to post
Share on other sites

There are some converters out there (like on Ebay) that will convert CGA, EGA, video arcade, etc to VGA.  They're generally not terribly expensive.

 

I'm thinking maybe I ought to grab one just so I've got the solution around.

Share this post


Link to post
Share on other sites

yea im not interested in the converters..  the EGA/RGB monitors looked different especially in a dark room at night when your 10 years old playing DOS video games ;)

i just wanted to get that 16 color glow one more time! for nostalgia purposes, i never had a mac when i was 10 i had a tandy 1000 that was my own computer. (my dad had a tandy 3000)

 

anyways thanks for the info + replies

i thought the color plus 14" was an RGB monitor.. if its VGA my mistake

 

i actually did get a VGA ISA card for the 386.. and it works with my flatscreen just fine.. 

but i have many computers that use VGA display, i have one EGA adapter i was just 

looking to find a monitor to go with it. but they are impossible to find now

Edited by supernova777

Share this post


Link to post
Share on other sites

anyways thanks for the info + replies

i thought the color plus 14" was an RGB monitor.. if its VGA my mistake

VGA monitors are "RGB". (As are those Mac monitors) RGB just means "Red Green Blue", IE, a color monitor that uses varying intensities of those three hues to encode color information. EGA monitors are a variation of *digital* RGB monitors, IE, the RGB information is encoded as on-off signals on one or more wire per color. (Specifically EGA uses 6 bit color encoding, with two wires for each color for a maximum of 64 colors on the palette, although you can only see the full palette in the 640x350 line mode. The 200 line modes most commonly used for games use CGA-compatible RGBI encoding, IE, 1 bit per color for 8 hues and 1 intensity bit that affects all three for a total of 16 "colors" counting "light black" and "dark white".) VGA uses "Analog" RGB encoding, in which there's a single wire with a varying voltage level for each color. There are non-VGA compatible Analog RGB monitors so far as that goes, such as the monitors sold for Commodore Amigas and Atari STs, so just looking for an "RGB" monitor isn't really going to help you much.

 

If you just want to run games you can try finding a CGA monitor, they're far more common, and set up your EGA card's DIP switches appropriately. This was actually a pretty common configuration and it will let you run most EGA games, which ran mostly in the 320x200 and 640x200 modes.

Edited by Gorgonops

Share this post


Link to post
Share on other sites

There are some converters out there (like on Ebay) that will convert CGA, EGA, video arcade, etc to VGA.  They're generally not terribly expensive.

 

I'm thinking maybe I ought to grab one just so I've got the solution around.

So those won't do what the OP wants either.

 

In the arcade world, "CGA" is what people use to refer to 15 kHz h-sync, 60 Hz v-sync (TV timings) analog RGB, and "EGA" is what people use to refer to 24 kHz h-sync.

 

Those converters sample the 15 kHz or 24 kHz analog RGB signal, and output a VGA signal. They don't support actual CGA or actual EGA's digital color standard.

Share this post


Link to post
Share on other sites

And, actually, EGA timings aren't actually 24 kHz, they're 21.85 kHz.

 

(Oh, and for the sake of completeness, while I've been saying "15 kHz" for CGA h-sync, it's really 15.734 kHz.)

 

Now, one of those cheap CGA/EGA/YUV to VGA boards will get a CGA (or 320x200/640x200 EGA signal, but not 640x350 or EGA text mode - the actual EGA scanrate isn't within the allowable range for these boards) signal up on a VGA monitor, but only with 8 colors. You could also build a color decoder circuit to convert the TTL colors to analog, and that would get you the full 64 color palette.

Edited by bhtooefr

Share this post


Link to post
Share on other sites

... but only with 8 colors. You could also build a color decoder circuit to convert the TTL colors to analog, and that would get you the full 64 color palette.

 

Quick minor correction: EGA only has the 16 color CGA-compatible RGBI palette in the 200 line modes compatible with those arcade scalers. It's basically non-negotiable outside of performing hardware modifications to both the card and the monitor. It is of course possible to build RGBI converters that work with those boards to get the full 16 colors, there are plans floating around that can be found with a simple Google. A simple, not entirely-accurate-to-the-original can be built with completely passive components (IE, resistors), but standard CGA/EGA monitors contained a hardware hack to turn the muddy "dark yellow" color that's produced by the unweighted RGBI algorithm into a more eye-pleasing brown, to replicate that you need a logic gate.

Share this post


Link to post
Share on other sites

If you were willing to settle for CGA resolution here's one for $35:

 

http://www.ebay.com/itm/Vintage-High-Resolution-RGB-14-Color-Monitor-Parco-RGB-640-14-Fine-Tune-Cntrls-/122198205195?hash=item1c7394a30b:g:VnYAAOSwNRdYBnL4

 

It's actually sort of shocking to me how rare digital RGB monitors are on eBay and what they're going for. I guess they *have* all hit the recyclers at this point.

One more note on the combination of an EGA card and a CGA monitor: it was a pretty common combination (I had an IBM 5150 PC with a Paradise EGA card and a CGA monitor myself for a while) and if it's the retro look you want when playing things like the original Duke Nukem, Commander Keen, or whatever these will all look the same on a CGA monitor connected to an EGA card as they'd look on an EGA capable monitor. The only thing you lose is the 350 line mode... and if you're willing to go blind that might not even be true if you do indeed have an ATI EGA Wonder card. The EGA Wonder is a positively magical card and can display 350 line EGA modes on a CGA monitor using some dark dithering magic and interlacing. It'll flicker like an Amiga doing so but you can do it. You can even hook up an original IBM MDA/Hercules monochrome monitor and display color software in shades of gray using its dark sorcery.

(Honestly a mono monitor might be more period correct with a 386/40, because while EGA was long dead by 1992 skinflints were still buying mono monitors at that late date.)

Share this post


Link to post
Share on other sites

You could also build a color decoder circuit to convert the TTL colors to analog, and that would get you the full 64 color palette.

 

How difficult would it be to do a converter from 9-pin TTL video cards that output FPD and TPD resolutions back in the day to VGA? There are lots of VidCards from the dawn of DTP floating around with no monitors to hang off them. B&W and Grayscale ought to be easier than color I would think.

Edited by Trash80toHP_Mini

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×