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Erik
March 19th, 2004, 08:00 PM
I just got finished playing with my newest machine.

It was delivered a few hours ago.

A pristine (and I do mean that literally) IBM PC AT.

This is a 6 MHz, 512K machine with the 256/512K motherboard and the "stacked" RAM chips.

It's so early it has a CGA card and monitor rather then an EGA card.

It came with everything it shipped with, except the box. The Guide to Operations, Setup manual, DOS and BASIC manuals, the cover plate for the back of the unit and the IBM logo keys.

It also came with a very early Microsoft Mouse (the old two-button beast, but not the green button style) with the manuals and software for that and a Hayes Smartmodem card, complete with docs and software. I'm 99% sure this is a 300 baud modem. I'll have to check the manual to be sure.

An IBM ProPrinter with manual was also included.

But here's the real kicker. . . It still has the original 20 MB CMI hard drive - and it works!

The beast booted straight up into DOS 3.10. A Chkdsk yielded a few "lost clusters" but nothing serious.

I'm very impressed that a machine this original, complete and functional still existed in the wild. . .

Now, where is my copy of Windows 286?

Erik

Terry Yager
March 20th, 2004, 07:09 AM
Congratulations, Erik! Sounds like a nice score. (Hope it didn't set ya back too much, but it's probably worth every penny).

--T

mbbrutman
March 20th, 2004, 10:55 AM
Ah, another owner of a working CMI drive. Now I know of 2. We need to start a club.

An AT could be configured with CGA instead of CGA from the factory. Many of them where I work were only equiped with monochrome display adapters.


Mike

Super-Slasher
March 20th, 2004, 11:10 AM
Lucky! Especially having an original Mouse Systems mouse... manuals, too.

You going to scan those manuals? hehe :lol:

I still have the name and place of that company that repairs Winchester drives; I still want to get my original Seagate/IBM 20MB drive repaired sometime in the future for my PC AT. Should your CMI ever start to go, these would be the people to call:

http://www.directrepairlabs.com/prods_servs/disk_drives/disk_drives.htm

Toll-free number can be found somewhere on their webpage.

CP/M User
March 20th, 2004, 12:34 PM
"Erik" wrote:

> It's so early it has a CGA card and
> monitor rather then an EGA card.

AFAIK, those machines don't support
anything higher than a CGA card.

Now you can go and explore the world
of CGA, compile some programs I
posted here (130Colours) & see what
other handy little routines are out there
to help improve things like Text Blinking
(if you don't like it!).

> It came with everything it shipped
> with, except the box. The Guide to
> Operations, Setup manual, DOS and
> BASIC manuals, the cover plate for
> the back of the unit and the IBM logo
> keys.

What do you mean it came with
everything except the Box, oh the
original box the machine came in! ;-)

> But here's the real kicker. . . It
> still has the original 20 MB CMI
> hard drive - and it "works!"

I think you should persurve that,
because I think once they go, that's
it, their worth nothing.

Cheers,
CP/M User.

Erik
March 20th, 2004, 01:46 PM
AFAIK, those machines don't support
anything higher than a CGA card.

Now you can go and explore the world
of CGA, compile some programs I
posted here (130Colours) & see what
other handy little routines are out there
to help improve things like Text Blinking
(if you don't like it!).

The EGA and PGA adaptors were introduced around the time of the AT. They were more expensive than CGA (in the case of PGA, much more) but they were typically used in the higher end machines.

Since I've already got CGA on one of my 5150 PCs as well as my 5155 PC Portable I'll probably look for an EGA card and display for this machine. . .

Erik

Terry Yager
March 20th, 2004, 02:25 PM
Since I've already got CGA on one of my 5150 PCs as well as my 5155 PC Portable I'll probably look for an EGA card and display for this machine. . .

Erik

Try and locate an EGA Wonder card from ATI. It has the proper (internal) connector for your IBM Portable PC, and will allow you to run EGA resolution on the internal monitor (or any CGA). It interlaces the display in EGA mode, but it's not too hard on the eyes, a little flickery, but not too bad. (I had one in my PPC, till I sold it).

--T

Super-Slasher
March 20th, 2004, 02:40 PM
Try and locate an EGA Wonder card from ATI.

I think I may have one or two floating around. I'll check if you want me to, Erik. Got tons of old vid cards.

mbbrutman
March 20th, 2004, 05:15 PM
CPM User:

ATs definitely support EGA cards, and the EGA card was introduced at the same time as the AT. Heck, at AT will even support SVGA if you give it a 16 bit ISA card.

CGA was the cheaper option that allowed you to use your existing monitor.

EGA can use a CGA monitor, but not all of the modes are available if you do that. The 320x200 and 640x200 modes are available in more colors than CGA (16 at a time out of a palette of 4096). There was an extended mode that was 640x350 that you needed a real EGA monitor for.

Interesting side note - not all PCs can run EGA or VGA cards. I have an oldie with a BIOS from 10/81, and it doesn't scan the BIOS for extensions. As a result, I can't put a hard disk, EGA, VGA or any other card that has a BIOS extension on it - the BIOS extension won't be seen. PCs with a later BIOS scan the ROM areas for BIOS extensions, and thus can use those types of cards.

Erik
March 20th, 2004, 07:32 PM
Try and locate an EGA Wonder card from ATI. It has the proper (internal) connector for your IBM Portable PC, and will allow you to run EGA resolution on the internal monitor (or any CGA). It interlaces the display in EGA mode, but it's not too hard on the eyes, a little flickery, but not too bad. (I had one in my PPC, till I sold it).

I may look for one for tooling around, but I'm a bit of a purist and would prefer an IBM tagged EGA card and display (5154? I can't remember which designation they gave that one).

Maybe someday I'll put this AT in a VCF booth. . . :)


Interesting side note - not all PCs can run EGA or VGA cards. I have an oldie with a BIOS from 10/81, and it doesn't scan the BIOS for extensions. As a result, I can't put a hard disk, EGA, VGA or any other card that has a BIOS extension on it - the BIOS extension won't be seen.

I've got one of those too. If it boots to BASIC 1.00 then you can't do any of the things you mentioned. It's also limited to something less then 640K of RAM (I want to say 576K)

Erik

Terry Yager
March 20th, 2004, 07:42 PM
I may look for one for tooling around, but I'm a bit of a purist and would prefer an IBM tagged EGA card and display (5154? I can't remember which designation they gave that one).

Oh, OK...just make sure you get the 64K daughterboard with it, for a total of 128K.


Maybe someday I'll put this AT in a VCF booth. . . :)


Erik
That should make a nice display, especially if you do find an IBM EGA monitor to go with it.

--T

Super-Slasher
March 20th, 2004, 07:55 PM
just make sure you get the 64K daughterboard with it, for a total of 128K.

Where would one find this type of daughterboard, curiously? never heard of it before. I'm still holding out for a PGA monitor and vid card for my AT, though, hehe.

Terry Yager
March 20th, 2004, 09:20 PM
just make sure you get the 64K daughterboard with it, for a total of 128K.

Where would one find this type of daughterboard, curiously? never heard of it before. I'm still holding out for a PGA monitor and vid card for my AT, though, hehe.

EBay, of course. (Where else)? Good luck trying to find a PGA adaptor, they're very rare. (Wasn't that one of those double cards, that take up two slots)? I've only ever even seen one of them, and that was many years ago. I did useta have another vid card that looked a lot like the IBM PGA in my "wierd card" collection, but it was made by another company whose name eludes me just now. It was also a two-in-one card. I never did figger out how to make it work tho, even as CGA.

IBM EGA cards came with 64K on-board, but they have two multi-pin connectors, one on either side of the RAM chips. That is where you plug in the daughterboard for the extra memory (another 64K). I don't recall exactly what the limitations of the 64K configuration are, but it shouldn't be hard to look up on the net. The fully configured card shouldn't be too hard to find, they used to be fairly common. The ratio is probably about 2:1, as about half of the buyers went for the extra memory option. (At least in my experience, about every other one I've seen had it installed).

--T

CP/M User
March 20th, 2004, 10:50 PM
"Erik" wrote:

>> AFAIK, those machines don't support
>> anything higher than a CGA card.

>> Now you can go and explore the world
>> of CGA, compile some programs I
>> posted here (130Colours) & see what
>> other handy little routines are out there
>> to help improve things like Text Blinking
>> (if you don't like it!).

> The EGA and PGA adaptors were
> introduced around the time of the AT.

Oh sorry, I'm getting the AT mixed up
with the Personal Computer! :-(
I'm not very good when it comes to
those two machines.
Reason why I thought that was cause
you were talking about the 512k
motherboard, which would make
that a heavily expanded PC.

> They were more expensive than CGA
> (in the case of PGA, much more) but
> they were typically used in the higher
> end machines.

> Since I've already got CGA on one of
> my 5150 PCs as well as my 5155 PC
> Portable I'll probably look for an EGA
> card and display for this machine. . .

Oh okay, I wouldn't recommend running
those CGA programs then, it may
destroy that EGA card of yours!

Cheers,
CP/M User.

CP/M User
March 20th, 2004, 11:00 PM
"mbbrutman" wrote:

> ATs definitely support EGA cards,
> and the EGA card was introduced
> at the same time as the AT. Heck,
> at AT will even support SVGA if
> you give it a 16 bit ISA card.

Okay, I'll just point you to the message
I posted to Erik. I get muddled with
Personal Computers (from '81) & ATs
(about '84 they came out didn't they?).

Anyway the AT I once saw looked like
an PC (though that was IBM for you
putting different machines in simular
boxes - look at the XT!) ;-)

> CGA was the cheaper option that
> allowed you to use your existing monitor.

Sorry, did I forget to mention that I had a
CGA myself & have written numerious
programs with it! ;-)

> EGA can use a CGA monitor, but not
> all of the modes are available if you
> do that.

That's interesting to know, I've got a
perfectly good monitor with my CGA,
but my EGA one is a dud. Could I plug
my monitor I use for my CGA into that
EGA (I know the connections are the
same - 9 pin).

> The 320x200 and 640x200 modes
> are available in more colors than
> CGA (16 at a time out of a palette
> of 4096). There was an extended
> mode that was 640x350 that you
> needed a real EGA monitor for.

Oh okay, I'd better just find an EGA
monitor then.

> Interesting side note - not all PCs
> can run EGA or VGA cards. I have
> an oldie with a BIOS from 10/81,
> and it doesn't scan the BIOS for
> extensions. As a result, I can't
> put a hard disk, EGA, VGA or any
> other card that has a BIOS extension
> on it - the BIOS extension won't
> be seen. PCs with a later BIOS
> scan the ROM areas for BIOS
> extensions, and thus can use
> those types of cards.

That's why is sometimes handy to
expand the BIOS! ;-)

Cheers,
CP/M User.

Super-Slasher
March 21st, 2004, 05:42 AM
http://incolor.inebraska.com/bill_r/ibm_pga_graphics_adapter.htm The massive brute known as the IBM PGA adapter.

If I can remember correctly, the IBM PGA vid card had it's own 8088 GPU and 384KB of memory, displaying in resolutions of 640x480 and 256 colors out of a pallette of millions.

Terry Yager
March 21st, 2004, 07:14 AM
.

Anyway the AT I once saw looked like
an PC (though that was IBM for you
putting different machines in simular
boxes - look at the XT!) ;-)
[
Let's not forget the XT-286 (a strange & wonderous beast). It's a 286 mobo stuffed into an XT-type case. I would guess that they are rather rare today, tho.


That's interesting to know, I've got a
perfectly good monitor with my CGA,
but my EGA one is a dud. Could I plug
my monitor I use for my CGA into that
EGA (I know the connections are the
same - 9 pin).


Cheers,
CP/M User.

Some EGA cards (not IBM, IIRC) support TTL monochrome monitors too (with graphics). Some even have RCA jacks to use a composite color monitor.

--T

CP/M User
March 21st, 2004, 12:32 PM
"Terry Yager" wrote:

> Some EGA cards (not IBM, IIRC)
> support TTL monochrome monitors
> too (with graphics). Some even
> have RCA jacks to use a
> composite color monitor.

Some people I've heard from say
that they have seen a true graphical
program on a MDA being done. While
they do believe it's not possible to
easily access this, with some complex
code, it's possible. I believe the
program they saw was a Fractal
demostration, which was written in C.

But I've been trying to see if there's
other programs out there.
Unfortunately, I don't have a real Mono
card, I dohave a green screen here
which has a rounded connection on it,
could this be the same as the IBM's
monitor?

Cheers,
CP/M User.

Terry Yager
March 22nd, 2004, 04:20 AM
http://incolor.inebraska.com/bill_r/ibm_pga_graphics_adapter.htm The massive brute known as the IBM PGA adapter.

If I can remember correctly, the IBM PGA vid card had it's own 8088 GPU and 384KB of memory, displaying in resolutions of 640x480 and 256 colors out of a pallette of millions.

Nice link, TNX. So it's 3 boards and 2 slots? I wasn't aware that it needed a special monitor tho. Do you know what kind? Analog? TTL?

--T

Super-Slasher
March 22nd, 2004, 05:00 AM
The PGA card required a special PGA monitor to operate; as far as I know, different types of monitors were not interchangable with this card (CGA, EGA, etc.).

When IBM offered PGA for its line of computers before S/VGA become the standard, from 1984 to 1987, the monitor and video card together cost almost $6000 - almost the same price as a PC AT with an EGA monitor.

-EDIT- Also I made a mistake: the pallette for the PGA card was not millions, but infact 4096 colors. Still might impressive at the time, when most color monitors and video cards only had a pallette of up to 256.

Barry
March 22nd, 2004, 07:17 AM
Some people I've heard from say
that they have seen a true graphical
program on a MDA being done. While
they do believe it's not possible to
easily access this, with some complex
code, it's possible. I believe the
program they saw was a Fractal
demostration, which was written in C.

I suspect this was a Hercules card and not a true MDA card. Hercules made a card that was an MDA clone and included the ability to do graphics. If I remember correctly it was 768x348 graphics or something like that.

There was no BIOS interrupt to put it into graphics mode. That required accessing the cards ports to set the mode. And if you did it wrong the monitor burned up. Most people, me included, just "borrowed" some known good code to set the modes rather than risk the monitor till you got it right.

When it wasn't in graphics mode it was just like a normal MDA card.

I had one for a long time. They were kind of a de-facto standard on PC clones. I did my first PC graphics programming on one. Just some sprite graphics.

Barry

CP/M User
March 22nd, 2004, 12:12 PM
"Super-Slasher" wrote:

> -EDIT- Also I made a mistake: the pallette
> for the PGA card was not millions, but
> infact 4096 colors. Still might impressive at
> the time, when most color monitors and
> video cards only had a pallette of up to
> 256.

4096 colours cerainally has some significance
between machines. When the Amstrad CPC
Plus was introduced around 1990, it came out
with support for 4096, this was Amstrads way
of trying to compete with the Amiga. While
it worked well, I have no idea why it flopped,
perhaps the Amiga had become to established,
however Amstrad never marketed this CPC
Plus to Australia (not that it might of made a
difference! ;-)
As a conserquence, many of us with regular
Amstrads kept them.

Cheers,
CP/M User.

CP/M User
March 22nd, 2004, 12:23 PM
"Barry" wrote:

> I suspect this was a Hercules card and
> not a true MDA card. Hercules made a
> card that was an MDA clone and
> included the ability to do graphics. If I
> remember correctly it was 768x348
> graphics or something like that.

I'll have to get back to you on this, however
I do know about the Hercules card & it's
graphical abilities (even though it's just
mono).

I'm pretty sure that the person I was
talking to about this certainally knows about
the Hercules card. The code they were
describing to me (while it was in C), looked
far more complicated than anything they
have ever seen & they simply couldn't
explain it to me. I'll see if I can get this
code, so that I can have a look.
Anyway, I should imagine that it wouldn't be
too difficult to do some graphics on a Herc.

> There was no BIOS interrupt to put it into
> graphics mode. That required accessing
> the cards ports to set the mode. And if
> you did it wrong the monitor burned up.

That's basically the deal when you get your
ports all messed up.

> Most people, me included, just "borrowed"
> some known good code to set the modes
> rather than risk the monitor till you got it
> right.

> When it wasn't in graphics mode it was
> just like a normal MDA card.

> I had one for a long time. They were
> kind of a de-facto standard on PC clones.
> I did my first PC graphics programming
> on one. Just some sprite graphics.

Oh well, I'll see if I can get this so-called
code for doing graphics on a MDA &
perhaps post it here, I wouldn't recommend
trying to run it on anything else though,
otherwise it may do what you said & burn
up.

Cheers,
CP/M User.

mbbrutman
March 23rd, 2004, 10:25 AM
The XT-286 is supposed to be even faster than the AT, even though they use the same processor. The XT-286 uses zero wait-state RAM, which is what makes the difference. (Wait states kill performance.) It's a newer design the AT, and they were able to take advantage of slightly better parts to do that.

Terry Yager
March 23rd, 2004, 10:40 AM
The XT-286 is supposed to be even faster than the AT, even though they use the same processor. The XT-286 uses zero wait-state RAM, which is what makes the difference. (Wait states kill performance.) It's a newer design the AT, and they were able to take advantage of slightly better parts to do that.

Yeah, I just read that the other day. The XT-286 came out in 1986. I always thought they came out at the same time as the AT, in 1984 (and that IBM just made 'em to get rid of a bunch of ol' XT cases they had layin' around).

--T

CP/M User
March 23rd, 2004, 02:01 PM
"Terry Yager" wrote:

> ...(and that IBM just made 'em to get rid
> of a bunch of ol' XT cases they had layin'
> around).

Who knows! :-)

Cheers,
CP/M User.