I see no practical (compatibility) reason, personally .

If I was in your shoes, I would consider an XT class machine instead, ideally with CGA, to take advantage of CGA composite video . A 286 has just too much overlap with a 386, IMHO .

EDIT: And for all the directly bootable games that probably won't run on even a 286 .

That's an interesting thought... to be honest, I have little interest in CGA era games personally. There are a few that I remember, but my world started in the EGA realm.

I was partly thinking collectability and partly having a real EGA card and real EGA monitor. And honestly, partly because I think that combo looks cool.

I can't think of what I'd run on a XT machine, however your suggestion is a fair one, thank you 😀

Agree with darry ! If you are looking to buy one for later resale that is one thing but to buy one to play with you will be disappointed. The real IBM AT's were not like the later 12Mhz or 16Mhz clone 286's because they only ran at 6 or 8 Mhz and typically had limited original equipment. If you could find a complete IBM 5170 it would be great as collectors item but suck for actually using compared to even a late model clone Turbo XT.
For some reference:
https://en.wikipedia.org/wiki/IBM_Personal_Computer/AT

There's nothing particularly "practical" about owning vintage PCs anyway. You can just run all the games in DOSbox pretty nicely.
I'm not sure about you guys, but I build the PCs because I like the experience of playing with real hardware.
If you want an authentic 80s experience (even if there is overlap), then the AT would be a great choice...especially with the 84-key keyboard and EGA display.

I own a 5150 and a 5160, but neither of them are equipped with CGA. I have always hated 4 colour graphics. I would rather play games in hercules monochrome. I understand why it might have nostalgic value to a person who grew up with that, but I grew up with an Amiga 500 so I got to play the same games with better graphics and sound.
The composite mode of CGA is something I never got into, but if you want that then the Apple ][ would be a better choice.

I don't think even the best turbo XT can hold a candle to an AT.

If your only interest is vintage gaming, a turbo AT or 386 is probably your best starting point.

maxtherabbit wrote on 2020-08-17, 02:11:

I don't think even the best turbo XT can hold a candle to an AT.

If your only interest is vintage gaming, a turbo AT or 386 is probably your best starting point.

Are you kidding? I have both Turbo XT and a old 6MHZ 286 (like the original IBM AT) and the Turbo XT runs circles around it....
not sure how a Turbo AT would compare but the original IBM AT were horrible, and that was the OP question.

I do totally agree with Anonymous Coward !

TechDeals wrote on 2020-08-16, 20:36:

Yet I kinda want a real 286 for some strange reason.

You want to be able to lift your nose into the air at the table and say "I have a real AT..."

Horun wrote on 2020-08-17, 02:30:

Are you kidding? I have both Turbo XT and a old 6MHZ 286 (like the original IBM AT) and the Turbo XT runs circles around it.... […]
Show full quote

maxtherabbit wrote on 2020-08-17, 02:11:

I don't think even the best turbo XT can hold a candle to an AT.

If your only interest is vintage gaming, a turbo AT or 386 is probably your best starting point.

Are you kidding? I have both Turbo XT and a old 6MHZ 286 (like the original IBM AT) and the Turbo XT runs circles around it....
not sure how a Turbo AT would compare but the original IBM AT were horrible, and that was the OP question.

I do totally agree with Anonymous Coward !

Is your v20 clocked at 20MHz or something? Otherwise I don't see how that's really possible

maxtherabbit wrote on 2020-08-17, 03:31:

Horun wrote on 2020-08-17, 02:30:

Are you kidding? I have both Turbo XT and a old 6MHZ 286 (like the original IBM AT) and the Turbo XT runs circles around it.... […]
Show full quote

maxtherabbit wrote on 2020-08-17, 02:11:

I don't think even the best turbo XT can hold a candle to an AT.

If your only interest is vintage gaming, a turbo AT or 386 is probably your best starting point.

Are you kidding? I have both Turbo XT and a old 6MHZ 286 (like the original IBM AT) and the Turbo XT runs circles around it....
not sure how a Turbo AT would compare but the original IBM AT were horrible, and that was the OP question.

I do totally agree with Anonymous Coward !

Is your v20 clocked at 20MHz or something? Otherwise I don't see how that's really possible

I also have doubts. Maybe both the Turbo XT's memory and mainboard are faster, but the 286 CPU in itself is much more advanced than the 808x.

Also: The PC/XT bus is much slower than AT-Bus. Same for VGA/EGA vs CGA/Hercules.
The latter use the old Motorola CRTC and have a higher overhead than VGA.

Yes, VGA in 320x200@256c on a no-name VGA card causes less overhead than IBM CGA in 320x200@4c.
It's related to the different memory layouts (bit planes) and the CRTCs somehow.

Reminds me of an older thread, by the way. 😁
How fast is the nec v20 compared to a 286?

Actually the XT/3 uses a 8086-10 and most benchmarks never compare that to a 286-6. Maybe you can guess why 😀

Horun wrote on 2020-08-17, 01:29:

Agree with darry ! If you are looking to buy one for later resale that is one thing but to buy one to play with you will be disappointed. The real IBM AT's were not like the later 12Mhz or 16Mhz clone 286's because they only ran at 6 or 8 Mhz and typically had limited original equipment. If you could find a complete IBM 5170 it would be great as collectors item but suck for actually using compared to even a late model clone Turbo XT.
For some reference:
https://en.wikipedia.org/wiki/IBM_Personal_Computer/AT

It is not for resale, if I buy one, it'll be to keep.

In terms of the system itself, I'm assuming that I'd end up upgrading the internals to whatever "the best" they would support, within reason. For some reason I have it in my mind that I could replace the 8Mhz 286 chip with a 12 or 16Mhz CPU, but that might not be possible. Does it matter for EGA games? I don't know.

Anonymous Coward wrote on 2020-08-17, 01:53:

There's nothing particularly "practical" about owning vintage PCs anyway. You can just run all the games in DOSbox pretty nicely.

^ That right there... Of course most of this runs fine that way, but it isn't as much fun. I take pleasure in looking at the real deal.

Anonymous Coward wrote on 2020-08-17, 01:53:

I'm not sure about you guys, but I build the PCs because I like the experience of playing with real hardware. If you want an au […]
Show full quote

I'm not sure about you guys, but I build the PCs because I like the experience of playing with real hardware.
If you want an authentic 80s experience (even if there is overlap), then the AT would be a great choice...especially with the 84-key keyboard and EGA display.

I own a 5150 and a 5160, but neither of them are equipped with CGA. I have always hated 4 colour graphics. I would rather play games in hercules monochrome. I understand why it might have nostalgic value to a person who grew up with that, but I grew up with an Amiga 500 so I got to play the same games with better graphics and sound.
The composite mode of CGA is something I never got into, but if you want that then the Apple ][ would be a better choice.

Maybe what I need is an IBM 5170 case, but all new internals and put a 286/16 in there with late 80s hardware. I suspect everything was a bit too custom back then for that to work however.

maxtherabbit wrote on 2020-08-17, 02:11:

I don't think even the best turbo XT can hold a candle to an AT.

If your only interest is vintage gaming, a turbo AT or 386 is probably your best starting point.

I think if I'm being honest... I just like the look of the IBM AT and IBM EGA monitor on the desk. It just "feels" 1980s to me.

The only games that I'd run on it would be stuff from the late 80s that never got a VGA release.

I'd almost like a Tandy 1000 if it weren't a Tandy. 😀 (yea, I know, ouch, maybe I'll get one at some point!)

hwh wrote on 2020-08-17, 03:03:

TechDeals wrote on 2020-08-16, 20:36:

Yet I kinda want a real 286 for some strange reason.

You want to be able to lift your nose into the air at the table and say "I have a real AT..."

If I'm being 100% honest... that's probably 1/3 of it right there. Without the nose lifting part... I'd mostly say it to myself when I look at it.

The 80286 isn’t *that* advanced. It’s main claim to fame is that it has a seldom used protected mode. Most of the extra speed comes from the 16-bit memory. An 8086 should be 80% as fast as a 286 at the same clock speed.

darry wrote on 2020-08-16, 20:46:

I see no practical (compatibility) reason, personally .

If I was in your shoes, I would consider an XT class machine instead, ideally with CGA, to take advantage of CGA composite video . A 286 has just too much overlap with a 386, IMHO .

EDIT: And for all the directly bootable games that probably won't run on even a 286 .

Even if I dislike the basic 4 colour CGA RGB mode (even if using it for some years growing up), I would strongly suggest to stay away from the composite version of it. Really poorly supported, and the games that do support it, is often quite buggy and with wrong colour palettes. I agree with C&T to go for Apple II if you would like to have great games with composite video support.

The only CGA modes I like is the PCjr enhanced CGA. But I would recommend a nice Tandy 1000 series machine instead of the IBM PCjr. That is (IMO) the absolutely pinnacle of DOS gaming on 8088/86. Additional benefit is that you also get the PCjr/Tandy sound support as an option in many games instead of PC speaker sound.

Otherwise I really prefer EGA way over CGA. EGA makes for a nice addition to playing many old DOS games!

I really love the clean design and the looks of the original IBM AT (the best looking IBM machine in history IMHO), but for me personally I would skip it. For me it is too big and bulky.

My dream scenario would be to have to be an IBM 5170 upgraded with a full-sized AT 386 or 486 motherboard... if only there were a VGA monitor in the "classic" IBM PC series. There is IBM 5175, but it's not exactly VGA. Maybe it would be possible to find a similarly designed VGA screen from Amdek or something like that?

I really like classic IBM PCs, but I wouldn't know what to do with a pre-386 computer. And yeah, I don't think it's sacrilege to upgrade a motherboard in a classic IBM — after all, the 3rd party motherboards were made to be compatible for a reason 😀

martinot wrote on 2020-08-17, 10:03:

Even if I dislike the basic 4 colour CGA RGB mode (even if using it for some years growing up), I would strongly suggest to stay away from the composite version of it. Really poorly supported, and the games that do support it, is often quite buggy and with wrong colour palettes. I agree with C&T to go for Apple II if you would like to have great games with composite video support.

I have an original Apple IIgs that I've owned since 1989, so I'm covered for composite!

martinot wrote on 2020-08-17, 10:03:

The only CGA modes I like is the PCjr enhanced CGA. But I would recommend a nice Tandy 1000 series machine instead of the IBM PCjr. That is (IMO) the absolutely pinnacle of DOS gaming on 8088/86. Additional benefit is that you also get the PCjr/Tandy sound support as an option in many games instead of PC speaker sound.

Darn it, now you want me to get a Tandy 1000? Grumble...

You know, I should be more keen on those, I'm an avid fan of The 8-bit guy and his Tandy videos. Time go to watch those again!

martinot wrote on 2020-08-17, 10:03:

I really love the clean design and the looks of the original IBM AT (the best looking IBM machine in history IMHO), but for me personally I would skip it. For me it is too big and bulky.

I'm in the happy space that... well... space isn't a huge issue. They are big, but I agree with you, they look like a million bucks! The PS/2 was ugly IMHO.

Anonymous Coward wrote on 2020-08-17, 07:52:

The 80286 isn’t *that* advanced. It’s main claim to fame is that it has a seldom used protected mode. Most of the extra speed comes from the 16-bit memory. An 8086 should be 80% as fast as a 286 at the same clock speed.

"The 80286's performance was more than twice that of its predecessors (the Intel 8086 and Intel 8088) per clock cycle. In fact, the performance increase per clock cycle of the 80286 over its immediate predecessor may be the largest among the generations of x86 processors. Calculation of the more complex addressing modes (such as base+index) had less clock penalty because it was performed by a special circuit in the 286; the 8086, its predecessor, had to perform effective address calculation in the general ALU, taking many cycles. Also, complex mathematical operations (such as MUL/DIV) took fewer clock cycles compared to the 8086."

Source : http://www.computinghistory.org.uk/det/6187/I … 00-transistors/

Edit: Comparing is difficult here. It's like comparing a 6502 and an 68010.? 😁
The 80186 and V30 are closer to the 286, I believe. The V20/30 is a real CPU, also.

It reminds me a lot of the Z80, which used hard-wired instructions instead of microcode,
and was more advanced than the 808x, also, despite being from a previous generation.
Ironically, the Z80 could work with 16-Bit values, despite having an 8-Bit adress-space (64KB) only.
In some way or another, this is like the old i8080 vs Z80 rivalry.

Anyway, I try my best to be open-minded in this case.
Would be interesting to find out the"truth".
Maybe that's a case for the Mythbusters? 😉

Edit: There's something else that comes to mind: BIOS performance.
The original IBM AT had a very limited BIOS, which wasn't optimized really and lacked a ROM Setup.
Back in the 80s it was not uncommon to use an alternate BIOS, like the one from Quadtel.
This makes me wonder how much performance was bottlenecked because of the BIOS in general. We're the ROM chips interleaved? Was access time 70ns or 250ns?
Did the Turbo XTs use Shadow Memory (BIOS copied to RAM)? Did Turbo XTs use waistates?