• Please review our updated Terms and Rules here
  • Exhibitor application for VCF West 2022 is now open! If you are interested in exhibiting, please fill out the form here.

Finally got an XT-286!

Maverick1978

Veteran Member
Joined
Mar 29, 2010
Messages
1,966
Location
Florida, USA
Honestly, I never knew that there was an XT-286 until I read this forum. With that said.. I checked out my area's Craigslist this afternoon on a whim. Found an IBM XT-286 with an IBM Hercules Monochrome monitor, and an IBM clicky keyboard for $100 and less than an hour away. Spoke to the owner this evening. He's the sole owner of it, and upgraded the RAM on it in the early 1990's as he used it to work from home. While he doesn't remember the specs on the machine, he did say that it has no expansion cards, and while the machine has been in storage for the last 3 years, the hard drive was removed from the machine and kept in his office. It'll be interesting to see what kind of shape it's in; I'll be going to see it later this week.

Crossing my fingers that it works and that the battery hasn't leaked all over the place - then again, if it doesn't work and is damaged, it might be free - and fixable :) We'll see!
 

strollin

Experienced Member
Joined
Apr 16, 2008
Messages
344
Location
N. California, USA
One question that comes to my mind is, was the IBM XT-286 the world's first "Baby AT" system, or did aftermarket manufacturers already come up with a 286 motherboard designed to fit into an XT-type case?
I honestly don't know if the XT-286 was the first baby AT but I do remember that when the XT-286 came out, it was crucified by the reviewers because it couldn't accept full height AT cards. Within a short time pretty much all full height AT cards had disappeared from the market and everyone was producing baby ATs.
 

strollin

Experienced Member
Joined
Apr 16, 2008
Messages
344
Location
N. California, USA
What is interesting about the XT-286 is that it runs at 6Mhz with 0 (zero) wait states for memory access while the AT has something like 1 or 2 wait states. This puts the performance of the XT-286 right between the 6Mhz and 8Mhz ATs. When I had my 5162 back in 1986, I changed out the 12Mhz crystal on mine to 18Mhz so I ended up with a 9Mhz machine which was faster than the 8Mhz AT for both a faster clock and faster memory access. IBM didn't want you to be able to do that so they had put some kind of speed check in the BIOS so the machine wouldn't boot if it was running faster than 6Mhz. I found a BIOS patch that jumped over the check, had to pull the BIOS, read contents to a file, edit the binary file to apply the patch then burn new BIOS with an EPROM burner. At the time, it was about as fast a 286 as you could get. Of course the clone mfrs came out with faster machines, I'm not sure what the fastest 286 clock speed ever was.
 

aitotat

Experienced Member
Joined
Aug 13, 2009
Messages
351
Location
Finland
Why is the IBM 5162 considered as an XT? Since it has 16-bit ISA slots, it must have two interrupt and two DMA controllers. I would consider it an AT if it also has RTC and keyboard controller on the motherboard. Does the 5162 support AT BIOS functions or only XT functions?
 

strollin

Experienced Member
Joined
Apr 16, 2008
Messages
344
Location
N. California, USA
I believe it was basically an AT motherboard designed to be shoehorned into an XT case. It had 16-bit slots, RTC and keyboard controller. The setup utility that came with the 5162 supported both the 5170 AT and the 5162 XT-286 for setting the CMOS options. It certainly had more in common with the AT than the XT.
 

modem7

Veteran Member
Joined
May 29, 2006
Messages
7,858
Location
Melbourne, Australia
From Scott Mueller's 'Upgrading and Repairing PCs' book,
"IBM introduced a new AT type of system disguised under the premise that it was IBM's fastest, most powerful PC XT."
"This model may look like an XT, but under the skin, it's all AT."
 

vwestlife

Veteran Member
Joined
May 2, 2008
Messages
5,131
Location
central NJ
IBM played the name-game tricks before, with the 5155 Portable PC. Despite the name, it was actually a Portable XT, minus the hard drive, and not based on the 5-slot 5150 PC motherboard, as many people were led to believe. I guess in IBM's thinking, they could not call it a Portable XT since it lacked a hard drive, although later (after the 5155 had already been cancelled) I believe they did offer floppy-only versions of the XT.
 

mikey99

Veteran Member
Joined
Jun 15, 2006
Messages
1,132
Location
NC , USA
Which floppy controller does your XT-286 use ?

From the pictures looks like its a floppy/hard drive combined card.
 

mikey99

Veteran Member
Joined
Jun 15, 2006
Messages
1,132
Location
NC , USA
Mine has a 16-bit combo floppy/hard controller.

I wonder if thats the original controller that came with the XT286. Yours has a 3.5 drive
so I think the original controller may not work for that 3.5 drive. Can you see any model
number on the card ? Maybe thats a Western Digital card.
 

strollin

Experienced Member
Joined
Apr 16, 2008
Messages
344
Location
N. California, USA
On the back of the card, "IBM 68X3815" and "WDC 60-000110-04 REV X4". I think it's the original controller and was made for IBM by Western Digital. My 3.5" drive is 720k, the controller may not have supported 1.44M though I'm not sure about that.
 

modem7

Veteran Member
Joined
May 29, 2006
Messages
7,858
Location
Melbourne, Australia
On the back of the card, "IBM 68X3815" and "WDC 60-000110-04 REV X4". I think it's the original controller and was made for IBM by Western Digital. My 3.5" drive is 720k, the controller may not have supported 1.44M though I'm not sure about that.
That controller is the same as the one supplied in the later 5170's.

It will handle 1.44 MB drives, and I'm sure that the 5162 BIOS supports 1.44 MB drives as well, because:
1. The (one and only one) BIOS for the 5162 is dated 04/21/86;
2. In 1985, IBM included 1.44 MB support in the BIOS for the 5170.
 

strollin

Experienced Member
Joined
Apr 16, 2008
Messages
344
Location
N. California, USA
XT-286 PCs show up several times a year - its just a matter of patience.
I bought one off eBay last year from a US seller - can't remember price but it was fairly cheap.
Airfreight to Australia was a much bigger cost :(
My XT-286 arrived in good shape and seems to be fairly original - single 1.2Mb FDD and 20Mb HDD.
Obtaining a GTO took more patience - they do seem to be rare.
You may be interested in some info re XT-286 keyboard:
I believe one correct part# is 1390120 - but there may also be others.
Look for silver IBM logo with black text plus removable cable with AT*connector
Additional comment; 1390120 differ from 1390131 IBM keyboards in that they do*NOT have the three LEDs in upper-right position for Num Lock, Caps Lock, Scroll Lock.
Cheers.
I dug thru some keyboards I have out in my barn and found one of the 1390120 keyboards.
 
Top