VOGONS


First post, by renejr902

User metadata
Rank Member
Rank
Member

Hi! since 2 or 3 years i'm searching a cga monitor for my ibm 5150, not necessary the original one, any brand, but i didnt find a deal good enough on ebay and i didnt find one in Montreal, Canada and marketplace. Right now im using my ibm 5150 with a oak vga card with a great utility for transform the vga monitor in cga mode for games and utilities. But i would like to put back the original isa cga color video card of the ibm 5150 so i need a cga to vga converter. But i remember that i need a special adapter if i remember well enough. the card works great with rca output, so i suppose the cga 9 pins should work.
Thanks for help.

( by the way in last year i just bought two 486 laptop and a pentium 1 and 2 laptop, i will show you pics soon. The P2 works great in dos because sb16 pro compatibility but its working with usbdos and jstick and i cpuld play dos games with usb controller its so cool like keen4-5-6. only jazz and doom are not compatible with usbdos and i tried a lot of games. )

Reply 1 of 28, by Trashbytes

User metadata
Rank Oldbie
Rank
Oldbie

So what you want is an adapter to convert the CGA signal from the CGA card to VGA ? If so then youll need something like this to convert the signal to a form the VGA monitor can accept.

https://www.ebay.ca/itm/155678278689

I have zero affiliation with this seller and the link is for information purposes only.

They are pretty cheap but you may need to make an enclosure for it, it could also be used for converting RCA game consoles to VGA too .. pretty useful device to have around.

The other option is to check your VGA card, quite a few of the ISA ones could actually do a CGA display mode along with an EGA one too, I have two cards myself that can do this and its pretty faithful to true CGA while looking clean on a VGA monitor.

Reply 2 of 28, by renejr902

User metadata
Rank Member
Rank
Member
Trashbytes wrote on 2024-08-21, 13:05:
So what you want is an adapter to convert the CGA signal from the CGA card to VGA ? If so then youll need something like this to […]
Show full quote

So what you want is an adapter to convert the CGA signal from the CGA card to VGA ? If so then youll need something like this to convert the signal to a form the VGA monitor can accept.

https://www.ebay.ca/itm/155678278689

I have zero affiliation with this seller and the link is for information purposes only.

They are pretty cheap but you may need to make an enclosure for it, it could also be used for converting RCA game consoles to VGA too .. pretty useful device to have around.

The other option is to check your VGA card, quite a few of the ISA ones could actually do a CGA display mode along with an EGA one too, I have two cards myself that can do this and its pretty faithful to true CGA while looking clean on a VGA monitor.

yes i have a vga card that actually do cga mode and you are right its pretty faithful to true CGA.

My topic is confusing, im sorry.

I want to put the original ibm cga video card back in my ibm 5150. So i need a converter that will take the cga signal and convert it to vga, to my vga crt monitor. i have 3 vga crt monitor, so i suppose one should be compatible. So if i understand correctly your ebay link should be ok. But would the screen be still cga 4 colors in my vga monitor with this adapter ? thanks for answer

Reply 3 of 28, by Trashbytes

User metadata
Rank Oldbie
Rank
Oldbie
renejr902 wrote on 2024-08-21, 14:57:
yes i have a vga card that actually do cga mode and you are right its pretty faithful to true CGA. […]
Show full quote
Trashbytes wrote on 2024-08-21, 13:05:
So what you want is an adapter to convert the CGA signal from the CGA card to VGA ? If so then youll need something like this to […]
Show full quote

So what you want is an adapter to convert the CGA signal from the CGA card to VGA ? If so then youll need something like this to convert the signal to a form the VGA monitor can accept.

https://www.ebay.ca/itm/155678278689

I have zero affiliation with this seller and the link is for information purposes only.

They are pretty cheap but you may need to make an enclosure for it, it could also be used for converting RCA game consoles to VGA too .. pretty useful device to have around.

The other option is to check your VGA card, quite a few of the ISA ones could actually do a CGA display mode along with an EGA one too, I have two cards myself that can do this and its pretty faithful to true CGA while looking clean on a VGA monitor.

yes i have a vga card that actually do cga mode and you are right its pretty faithful to true CGA.

My topic is confusing, im sorry.

I want to put the original ibm cga video card back in my ibm 5150. So i need a converter that will take the cga signal and convert it to vga, to my vga crt monitor. i have 3 vga crt monitor, so i suppose one should be compatible. So if i understand correctly your ebay link should be ok. But would the screen be still cga 4 colors in my vga monitor with this adapter ? thanks for answer

The adapter simply takes the CGA signal from your CGA card and converts it into a VGA signal the VGA monitor can display correctly, it shouldnt look any different from a CGA CRT but since its a VGA CRT it might be sharper/cleaner if anything.

Reply 4 of 28, by renejr902

User metadata
Rank Member
Rank
Member
Trashbytes wrote on 2024-08-21, 15:06:
renejr902 wrote on 2024-08-21, 14:57:
yes i have a vga card that actually do cga mode and you are right its pretty faithful to true CGA. […]
Show full quote
Trashbytes wrote on 2024-08-21, 13:05:
So what you want is an adapter to convert the CGA signal from the CGA card to VGA ? If so then youll need something like this to […]
Show full quote

So what you want is an adapter to convert the CGA signal from the CGA card to VGA ? If so then youll need something like this to convert the signal to a form the VGA monitor can accept.

https://www.ebay.ca/itm/155678278689

I have zero affiliation with this seller and the link is for information purposes only.

They are pretty cheap but you may need to make an enclosure for it, it could also be used for converting RCA game consoles to VGA too .. pretty useful device to have around.

The other option is to check your VGA card, quite a few of the ISA ones could actually do a CGA display mode along with an EGA one too, I have two cards myself that can do this and its pretty faithful to true CGA while looking clean on a VGA monitor.

yes i have a vga card that actually do cga mode and you are right its pretty faithful to true CGA.

My topic is confusing, im sorry.

I want to put the original ibm cga video card back in my ibm 5150. So i need a converter that will take the cga signal and convert it to vga, to my vga crt monitor. i have 3 vga crt monitor, so i suppose one should be compatible. So if i understand correctly your ebay link should be ok. But would the screen be still cga 4 colors in my vga monitor with this adapter ? thanks for answer

The adapter simply takes the CGA signal from your CGA card and converts it into a VGA signal the VGA monitor can display correctly, it shouldnt look any different from a CGA CRT but since its a VGA CRT it might be sharper/cleaner if anything.

ok thanks a lot. Last thing, i think i dont see a 9 pin cga port on the adapter. How do i connect it ? or what cable do i need ? thanks a lot again

Reply 5 of 28, by mkarcher

User metadata
Rank l33t
Rank
l33t
Trashbytes wrote on 2024-08-21, 15:06:
renejr902 wrote on 2024-08-21, 14:57:

I want to put the original ibm cga video card back in my ibm 5150. So i need a converter that will take the cga signal and convert it to vga, to my vga crt monitor. i have 3 vga crt monitor, so i suppose one should be compatible. So if i understand correctly your ebay link should be ok. But would the screen be still cga 4 colors in my vga monitor with this adapter ? thanks for answer

The adapter simply takes the CGA signal from your CGA card and converts it into a VGA signal the VGA monitor can display correctly, it shouldnt look any different from a CGA CRT but since its a VGA CRT it might be sharper/cleaner if anything.

"It shouldn't look any different" is debatable, although I guess in this thread, this is the correct way to explain it. Any adapter converting from CGA to VGA needs to include a scan doubler, so the 200 visible lines of the CGA image are displayed as 400 lines on a VGA-type monitor. The result of the double-scanning process is that pixels tend to look blockier on the VGA monitor, while you might be able to discern black lines between the individual 200 lines on a CGA monitor. This creates a different general impression of image softness/sharpness, which is why there is so much discussion about using shaders in DOSbox to emulate different kind of video systems.

Reply 6 of 28, by Trashbytes

User metadata
Rank Oldbie
Rank
Oldbie
renejr902 wrote on 2024-08-21, 15:12:
Trashbytes wrote on 2024-08-21, 15:06:
renejr902 wrote on 2024-08-21, 14:57:

yes i have a vga card that actually do cga mode and you are right its pretty faithful to true CGA.

My topic is confusing, im sorry.

I want to put the original ibm cga video card back in my ibm 5150. So i need a converter that will take the cga signal and convert it to vga, to my vga crt monitor. i have 3 vga crt monitor, so i suppose one should be compatible. So if i understand correctly your ebay link should be ok. But would the screen be still cga 4 colors in my vga monitor with this adapter ? thanks for answer

The adapter simply takes the CGA signal from your CGA card and converts it into a VGA signal the VGA monitor can display correctly, it shouldnt look any different from a CGA CRT but since its a VGA CRT it might be sharper/cleaner if anything.

ok thanks a lot. Last thing, i think i dont see a 9 pin cga port on the adapter. How do i connect it ? or what cable do i need ? thanks a lot again

The attachment s-l1600.jpg is no longer available
The attachment GBS-8200.gif is no longer available

Looks like it needs a separate break out cable to accept 5 pin CGA signals, it should be pretty easy to make up a cable for this. Second Image is the same design but with different labels for the ports .. CGA can be sent over component cables which is another way to do it. Because these are DIY boards you will have to do a little leg work to get it working.

Reply 7 of 28, by renejr902

User metadata
Rank Member
Rank
Member
Trashbytes wrote on 2024-08-21, 15:26:
Looks like it needs a separate break out cable to accept 5 pin CGA signals, it should be pretty easy to make up a cable for this […]
Show full quote
renejr902 wrote on 2024-08-21, 15:12:
Trashbytes wrote on 2024-08-21, 15:06:

The adapter simply takes the CGA signal from your CGA card and converts it into a VGA signal the VGA monitor can display correctly, it shouldnt look any different from a CGA CRT but since its a VGA CRT it might be sharper/cleaner if anything.

ok thanks a lot. Last thing, i think i dont see a 9 pin cga port on the adapter. How do i connect it ? or what cable do i need ? thanks a lot again

The attachment s-l1600.jpg is no longer available
The attachment GBS-8200.gif is no longer available

Looks like it needs a separate break out cable to accept 5 pin CGA signals, it should be pretty easy to make up a cable for this. Second Image is the same design but with different labels for the ports .. CGA can be sent over component cables which is another way to do it. Because these are DIY boards you will have to do a little leg work to get it working.

Can this do the job for the cable ? thanks

https://www.ebay.ca/itm/374551183373?_nkw=vga … %3ABFBM_sHr3K5k

or this:

https://www.ebay.ca/itm/372641239437?_nkw=con … ysAAOSwfw5f1~S5

or

https://www.amazon.ca/-/fr/gp/product/B09BQKX … 59N8WD0QT&psc=1

Reply 8 of 28, by wbahnassi

User metadata
Rank Oldbie
Rank
Oldbie

Sorry to say those devices are not going to work.
The GBS is not compatible with PC CGA. It is made for arcades. You can repurpose it to work for PC CGA, but you will need more circuitry around it.

rasteri covered such circuitry for the GBS on his YT channel. A similar device was also built by necroware. The GBS can be entirely bypassed if you have an LCD that supports 15KHz horizontal sync. Many upscalers can handle the sync for you, but GBS is probably the cheapest.. MCE2HDMI is a one-for-all solution combining all the above too.

And yes, Montreal is very dry and boring wrt finding retro PC stuff. I had much more luck in Toronto GTA. Unlucky you though, I sold a working CGA monitor last year. It could have been yours.

Turbo XT 12MHz, 8-bit VGA, Dual 360K drives
Intel 386 DX-33, TSeng ET3000, SB 1.5, 1x CD
Intel 486 DX2-66, CL5428 VLB, SBPro 2, 2x CD
Intel Pentium 90, Matrox Millenium 2, SB16, 4x CD
HP Z400, Xeon 3.46GHz, YMF-744, Voodoo3, RTX2080Ti

Reply 9 of 28, by BitWrangler

User metadata
Rank l33t++
Rank
l33t++

Bitwranglers secret search code "kitchen monitor"

Also these ICs do almost everything to convert to composite video https://www.worldofsam.org/products/motorola-mc1377p

Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.

Reply 10 of 28, by jtchip

User metadata
Rank Member
Rank
Member

See also the previous discussion on using the GBS-8200 to convert CGA.

Reply 11 of 28, by renejr902

User metadata
Rank Member
Rank
Member

thanks guys for all this information. if its too difficult or expensive to convert it, i will still trying to buy a cga monitor instead. yeah i missed yours, i was busy last 2 years. Thanks again guys

Reply 12 of 28, by Trashbytes

User metadata
Rank Oldbie
Rank
Oldbie

Sorry mate, I didn't know this little board cant do PC CGA without modding it .. which is rather odd considering it looks like it can do a lot of other things, a CGA monitor sounds like a good option and its nice to have one around. I wish I still had my 5162 a lovely 286 monster with a nice 5153 CGA monitor and whopping 20Mb MFM HDD, that old girl got some serious punishment from me playing Moraffs Dungeons of the Unforgiven and a shootem up called Overkill.

Fun times so I really hope you can find a nice CGA monitor for your machine and it doesnt cost you a kidney.

Reply 13 of 28, by renejr902

User metadata
Rank Member
Rank
Member

thanks 😀

Reply 14 of 28, by douglar

User metadata
Rank l33t
Rank
l33t

** oops, off topic, deleted ****

Last edited by douglar on 2024-08-26, 03:29. Edited 1 time in total.

Reply 15 of 28, by lti

User metadata
Rank Member
Rank
Member

For some reason, the arcade community calls 15kHz analog RGB "CGA" and 25kHz analog RGB "EGA." It really confuses the PC community like us.

Reply 16 of 28, by zb10948

User metadata
Rank Member
Rank
Member

Just buy MCE2HDMI if you need to upscale CGA.
Btw. I never saw VGA that's not basically compatible with CGA, but I never saw one that's 100% compatible either.

Reply 17 of 28, by dionb

User metadata
Rank l33t++
Rank
l33t++

We're all talking digital CGA from the DE-9 connector here, but the original IBM CGA also output analog composite, which was admittedly slightly fuzzy, but a ) is far better supported by newer devices (I have TFT screens with native composite in as well as any old CRT TV able to take NTSC composite input) and b ) quite a few games made use of the 'features' of NTSC composite to generate more colours than natively supported by CGA. Unless you intend to do serious work requiring you to spend long times looking at text on the screen, I'd recommend going down the composite route rather than the digital one.

Reply 18 of 28, by maxtherabbit

User metadata
Rank l33t
Rank
l33t

"slightly fuzzy" more like "looks like dog shit smeared on a screen"

Reply 19 of 28, by renejr902

User metadata
Rank Member
Rank
Member
dionb wrote on 2024-08-26, 12:05:

We're all talking digital CGA from the DE-9 connector here, but the original IBM CGA also output analog composite, which was admittedly slightly fuzzy, but a ) is far better supported by newer devices (I have TFT screens with native composite in as well as any old CRT TV able to take NTSC composite input) and b ) quite a few games made use of the 'features' of NTSC composite to generate more colours than natively supported by CGA. Unless you intend to do serious work requiring you to spend long times looking at text on the screen, I'd recommend going down the composite route rather than the digital one.

i tried the composite one, i dont like it at all for text and i have high quality crt tv. but some games like buggertime show 16 colors instead of 4 for pure cga. But i want a real digital cga monitor, like my 7-12 years old 😉