PDA

View Full Version : IBM PC 5150.... leave as standard or 'upgrade' to VGA?



paul.brett
April 5th, 2016, 07:16 AM
I have an IBM PC 5150, and admittedly, I've already been giving it some upgrades, like an XT-IDE card, but I'm wondering about replacing the Color Graphics adapter with VGA, so that I can use a (larger) modern display.

It seems that getting a compatible (8bit) VGA card is fraught with issues, not the least of which are cost.

Thoughts?

Stone
April 5th, 2016, 07:58 AM
There are some 16-bit VGA cards that work fine on my XT but none of them works on my PC. :-)

An EGA card will work fine on the PC and gives a wonderful VGA-like display on a Multisync monitor. I referenced the Multisync because I believe that they are currently cheaper and also easier to source than straight EGAs.

SomeGuy
April 5th, 2016, 08:30 AM
If you do or not is up to you and depends on what you are using it for.

I would not quite say that plugging in an 8-bit card is "fraught with issues", generally a card either will work or not. Since it was never well documented which cards were 8-bit and PC/XT compatible, it can be crap shoot if a model (or even sub-revision of a model) will work. Keep in mind many cards that have 16-bit connectors will work in 8-bit slots.

There are a couple of partial list here:
http://www.vcfed.org/forum/showthread.php?26432-8bit-Friendly-ISA-VGA-cards
http://minuszerodegrees.net/5150/vga/5150_vga.htm

Cost certainly is a headache. Most of the eBay supply from old surplus has long since dried up, it looks like most of what is out there these days is probably coming from collectors. I'm wishing I had picked up some more specific parts ages ago.

framer
April 5th, 2016, 08:38 AM
I've had little trouble getting 16bit card to work on 5150 and 5160 computers. Set the switch to "no display" and most of the cards have a jumper that let you use them in 8bit mode. They all work nice using most modern LCD monitors.

I prefer the old RGB and mono monitors for originality but monitors are getting very hard to come by that work without problems. About 1/2 the monitors that I've purchased were destroyed when shipped to me. I got 1 5153, a Zenith RGB and 2-5151 mono monitors. I baby them. I got two old perfect condition VGA monitors that I picked up free that were being thrown out.

Good Luck
framer

Stone
April 5th, 2016, 09:08 AM
I've had little trouble getting 16bit card to work on 5150 and 5160 computers.What 16-bit VGA card did you get to work on a 5150? Like I mentioned above, I've had success with the XT but not the PC.

vwestlife
April 5th, 2016, 09:24 AM
A plain, generic 16-bit VGA card with the Oak Technology Inc. OTI067/077 chipset works fine in my 5150 PC. I don't even need to change any jumpers; I just plug it in and it works. :) Like this:

http://www.ebay.com/itm/331764936918

Generally, the fancier the card is (Super VGA, high color, Windows acceleration, etc.) the less likely it is to work in an 8-bit ISA PC/XT system.

SomeGuy
April 5th, 2016, 09:36 AM
Like I mentioned above, I've had success with the XT but not the PC.
Interesting, from a software and expansion perspective there is very little different between the two.

What ROM BIOS version does your have? The very first ROM BIOS revision did not support ROM extensions like those used with VGA.

The only other difference I am aware of is a small range of I/O ports that aren't forwarded to the ISA bus that prevents use of a genuine IDE adaptor (hacked for 8-bit mode).

While I haven't tried it myself, my Headland Video 7 VGA 1024i card claims to be compatible with both the IBM PC and IBM XT.

Stone
April 5th, 2016, 10:02 AM
It's not the first ROM... I think it's the last version.

offensive_Jerk
April 5th, 2016, 10:05 AM
I had a couple 16-bit cards that work fine.
Modem7 has some cards documented here.
http://www.minuszerodegrees.net/5150/vga/5150_vga.htm

SpidersWeb
April 5th, 2016, 11:09 AM
I also found that replacing the 8088 CPU with a V20 CPU made many previously not comparable 16 bit VGA cards work just fine.

As for an opinion - personally I like to leave them as is, and if I wanted a larger screen for games/applications - I'd get a cheap clone and make that VGA.

Chuck(G)
April 5th, 2016, 11:17 AM
Doing anything that's reversible would seem to be harmless. Arming yourself with hacksaw and drill, however, maybe not so much.

Malc
April 5th, 2016, 11:30 AM
I use a 16-bit VGA card in my 5150 and it works fine, My vintage eyes prefer it to CGA.

Xacalite
April 5th, 2016, 04:28 PM
Keep in mind that 5150 may be too slow for VGA software, so you will probably keep using CGA graphics.
Standard VGA only offers limited compatibility with CGA, but many (S)VGA cards also offer special register-level CGA compatibility mode - make sure you use one of these cards.

KC9UDX
April 5th, 2016, 06:03 PM
Doing anything that's reversible would seem to be harmless. Arming yourself with hacksaw and drill, however, maybe not so much.

Even then there are times when I consider that okay. If it's something someone would have done at the time, I might consider it. But not too add a modern component, especially an ATX motherboard or the likes.

I sawed a hole in my C64 to attach a period correct numeric keypad for example. In 1986, I wouldn't have thought twice about it. And I'm not normally one to deface things like that.

Caluser2000
April 5th, 2016, 06:47 PM
I'd personally go vga if a suitable monitor isn't available for the isn't available.

Trixter
April 6th, 2016, 11:19 AM
I'm wondering about replacing the Color Graphics adapter with VGA, so that I can use a (larger) modern display.

If you all you need a larger display, and won't be doing anything crazy with CGA-specific graphics, then this will certainly work.

If you want to take advantage of VGA, keep in mind that most VGA graphics software may run quite slowly. Games that use EGA and VGA graphics have to update between 2x - 8x more video memory than CGA games. Text applications, however, will run quite nicely, and you'll have more rows and columns to play with.

There are ways to keep your authentic CGA card but connect it to a larger screen through CGA-to-VGA conversion (http://www.vcfed.org/forum/showthread.php?50569-IBM-C128-CGA-conversation-capture-and-VGA-display-success-stories).

paul.brett
April 8th, 2016, 08:34 AM
30533

A nice picture of the IBM pair to feast your eyes upon.