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itsvince725
April 14th, 2017, 05:08 PM
I just got a XT 286 today, which I understand to be a pretty uncommon find (it was mixed in with a stack of 5150s and 5160s, though I did see two PC 3270s in there). It's a bit rough on the outside and has no hard disk but the inside is clean and in pretty good shape.

However, despite looking really clean...it doesn't power on. Flipping the power switch does nothing. I'm sure the power supply is to blame somehow, but is it possible there's also something else preventing the machine from powering on?

lyonadmiral
April 14th, 2017, 05:51 PM
1. Where did you see TWO PC 3270's?
2. Take everything out of the machine; all cards and disconnect hard disk/floppy disk drives to get a minimum configuration then power it on... see what happens...

Chuck(G)
April 14th, 2017, 06:09 PM
However, despite looking really clean...it doesn't power on. Flipping the power switch does nothing. I'm sure the power supply is to blame somehow, but is it possible there's also something else preventing the machine from powering on?

Yes--it isn't uncommon for a capacitor on the motherboard to go short, which will keep the PSU from starting up.

Try running the power supply with the motherboard disconnected and only a hard drive for load.

itsvince725
April 14th, 2017, 06:16 PM
1. Where did you see TWO PC 3270's?
2. Take everything out of the machine; all cards and disconnect hard disk/floppy disk drives to get a minimum configuration then power it on... see what happens...

1. A store called Kemner's Surplus Warehouse in Pottstown, Pennsylvania. He's got all kinds of stuff. Macs, a bunch of IBM stuff including XTs/5150s, a few ATs, and stacks of PS/2s, a bunch of TRS-80s and CoCos...just tons of stuff. Some of his XTs are really rough and basically scrap, but the 286 I bought and the 3270s I saw on the one stack were still in good shape. Mind, these systems are incomplete and thus the original 3270 software is gone, though the coax cards may remain.

2. I will have to do that tomorrow. Fortunately there's only two cards in the machine so it won't take that long.

itsvince725
April 15th, 2017, 10:09 AM
I was wrong, there was three cards! A floppy/hard drive controller, a combination parallel/monochrome video card, and what I assume is a CGA card (it says COLOR GRAPHICS). The CGA card turned out to be the issue, as the machine powers up fine with the other two cards.

Can someone link me a nice service manual? I wanted to pull the floppy drive to check how the board looks underneath but couldn't figure it out...

Chuck(G)
April 15th, 2017, 10:21 AM
There were many, many manufacturers of color graphics cards (CGA); the schematic for the IBM-made version is in the IBM PC Technical reference.

But you probably don't need the tech ref; just check out all of the tantalum electrolytics on the board. They have a tendency to degrade and short with age, often giving up the ghost with a "bang!", but not always.

itsvince725
April 15th, 2017, 11:29 AM
Oh no, not a manual for the card (I want to put in like a 256KB VGA card anyway!) but a service manual for the XT itself! That will come in really handy if I have any more problems with the machine.

krebizfan
April 15th, 2017, 11:36 AM
Oh no, not a manual for the card (I want to put in like a 256KB VGA card anyway!) but a service manual for the XT itself! That will come in really handy if I have any more problems with the machine.

Do searches for the model number: 5162. Makes it easier to get results specific to the XT 286 instead of including the XT as well. Also, http://minuszerodegrees.net/5162/doco/5162_documentation.htm might help.

modem7
April 15th, 2017, 03:15 PM
Lots of IBM 5162 (XT/286) info at minuszerodegrees.net


... and what I assume is a CGA card (it says COLOR GRAPHICS).
"COLOR GRAPHICS" is seen on the IBM CGA card. Photo at [here (http://minuszerodegrees.net/5162/cards/5162_cards.htm#cga)].


The CGA card turned out to be the issue, as the machine powers up fine with the other two cards.

But you probably don't need the tech ref; just check out all of the tantalum electrolytics on the board. They have a tendency to degrade and short with age, often giving up the ghost with a "bang!", but not always.
On the IBM CGA card, C8 is the tantalum capacitor that often fails.


Can someone link me a nice service manual? I wanted to pull the floppy drive to check how the board looks underneath but couldn't figure it out...
The drive may be held in by a screw that is inserted/removed via the underside of the case.

itsvince725
April 15th, 2017, 07:43 PM
I thought that, but it's a half-height drive with an empty bay underneath. Maybe the whole assembly is screwed in?

I'm not sure yet what I'm going to use for a hard drive solution but I should put something in the gaping hole where a full height hard drive once resided. Maybe another full height drive or a 3.5 floppy and a half-height drive...

Chuck(G)
April 15th, 2017, 09:30 PM
Take a close look--often, half-height drives were accommodated by screwing them onto side-plates that slid into the full-height slot.

At this stage, I don't really trust any time-appropriate MFM drives. I marvel at how a machine that I have with a 30MB Quantum Q540 drive keeps chugging along. I've got it backed up against the day that I know is coming. You may want to consider picking up a 16-bit IDE controller (often comes with a floppy controller as well) and then just use CF card or DOM and forget about spinning rust altogether.

Malc
April 16th, 2017, 12:19 AM
I thought that, but it's a half-height drive with an empty bay underneath. Maybe the whole assembly is screwed in?

On my XT 286 the HH floppy drive is secured on a HH frame with blanking plate on the front with plates like [ These (http://www.minuszerodegrees.net/images3/ibm_side_plate_2.jpg) ], Remove the 2 screws 1 on the inside and 1 underneath in the recessed hole and the whole assembly can be withdrawn from inside the case.

Stone
April 16th, 2017, 03:05 AM
I'm not sure yet what I'm going to use for a hard drive solution but I should put something in the gaping hole where a full height hard drive once resided. Maybe another full height drive or a 3.5 floppy and a half-height drive...I've got an IBM 0665-38 30MB drive that runs well if that's of interest. It's originally from a 5170. It hasn't seen any use in the last 25 or so years other than to occasionally test it.

I'm not that all far from you so it might not need to be shipped.

clh333
April 16th, 2017, 04:00 AM
The drive is carried in a sub-assembly that is held in the chassis by a screw underneath, in a small well or indentation.

-CH-

itsvince725
April 16th, 2017, 07:34 AM
On my XT 286 the HH floppy drive is secured on a HH frame with blanking plate on the front with plates like [ These (http://www.minuszerodegrees.net/images3/ibm_side_plate_2.jpg) ], Remove the 2 screws 1 on the inside and 1 underneath in the recessed hole and the whole assembly can be withdrawn from inside the case.

Thanks!

I should probably grease up the rails on the floppy drive before I try putting disks in, and being able to get the drive out of the machine would make that a lot easier!

Wait...since this is an AT-class machine on the inside, can't I use a conventional IDE controller card instead of an XT-IDE?

Chuck(G)
April 16th, 2017, 07:42 AM
Yes, that's just what I was saying.

Malc
April 16th, 2017, 08:33 AM
As Chuck said, Yes, But note: When you remove the original MFM/Floppy controller from the XT 286 and replace it with a IDE controller, On boot up the IBM XT 286 bios throws a 601 error because it expects to find the original controller ( Like the 5170 does ), Then you got to press F1 to continue. I found this annoying So I swapped out the original IBM Bios for an AWARD one and problem solved. Also note, I found that the XUB is incompatible with the IBM XT 286 bios ( Like the 5170 ).

itsvince725
April 16th, 2017, 09:24 AM
What is the XUB? And I assume the BIOS chip is a socketed DIP?

Malc
April 16th, 2017, 09:49 AM
XUB = XTIDE Universal Bios

Yes BIOS chips are socketed at locations U34 and U35 on the XT 286 Motherboard.

itsvince725
April 16th, 2017, 10:54 AM
I guess that means I'll need two BIOS chips then.

First, I'll have to get a hard disk and OS for this thing. I was thinking maybe version 4.01 as it fixes the problems with IBM DOS 4.0 and supports both 1.44MB floppy drives and >32MiB hard drive partitions, but maybe I should just do MS-DOS 5.0.

Stone
April 16th, 2017, 11:09 AM
First, I'll have to get a hard disk and OS for this thing. I was thinking maybe version 4.01 as it fixes the problems with IBM DOS 4.0 and supports both 1.44MB floppy drives and >32MiB hard drive partitions...I have this... the box says 4.00 but the disks inside are 4.01:

http://www.vcfed.org/forum/attachment.php?attachmentid=37859&stc=1

http://www.vcfed.org/forum/attachment.php?attachmentid=37860&stc=1

37860


37859

Malc
April 16th, 2017, 11:21 AM
Yup 27C256 EPROMS with a speed rating of 150ns or faster will do, Or if you don't care just erase the originals and use them. Modem7 has bios images for the 5162 on his website (http://www.minuszerodegrees.net/index.htm). I use DOS 6.22 on mine, Down to personal choice really.

Chuck(G)
April 16th, 2017, 11:39 AM
I have this... the box says 4.00 but the disks inside are 4.01:

I've got the box with 4.00. You wouldn't like it--buggy as heck. I've got a pile of CSDs for it to make it usable.

itsvince725
April 16th, 2017, 01:23 PM
Yup 27C256 EPROMS with a speed rating of 150ns or faster will do, Or if you don't care just erase the originals and use them. Modem7 has bios images for the 5162 on his website (http://www.minuszerodegrees.net/index.htm). I use DOS 6.22 on mine, Down to personal choice really.

I don't own an EPROM programmer so maybe I can get someone to make me some. I'll also presumably need some kind of drive cage for the second full height 5.25 bay to add a 3.5 floppy and hard disk.

modem7
April 16th, 2017, 10:24 PM
As Chuck said, Yes, But note: When you remove the original MFM/Floppy controller from the XT 286 and replace it with a IDE controller, On boot up the IBM XT 286 bios throws a 601 error because it expects to find the original controller ( Like the 5170 does ), Then you got to press F1 to continue. I found this annoying So I swapped out the original IBM Bios for an AWARD one and problem solved. Also note, I found that the XUB is incompatible with the IBM XT 286 bios ( Like the 5170 ).
Thanks for this information (I do not own a 5162). I have updated minuszerodegrees.net accordingly.

Malc
April 17th, 2017, 01:51 AM
I don't own an EPROM programmer so maybe I can get someone to make me some. I'll also presumably need some kind of drive cage for the second full height 5.25 bay to add a 3.5 floppy and hard disk.

I suppose you could add a 3.5 floppy in a 5 1/4 to 3.5 adapter to the 1.2 Mb floppy using the fixing plates (if you have them), That's what i did until my 1.2 Mb died on me half way through writing to a floppy, Now i just have a 3.5" 1.44 Mb floppy in an adapter secured to the original HH frame. As for the second bay i removed the non-working MFM drive from the frame and have the frame secured in the bay with the drive activity LED wired up to the IDE controller. I currently have CF in mine with the XUB homed in a boot rom socket of a nic.

Malc
April 17th, 2017, 02:36 AM
Thanks for this information (I do not own a 5162). I have updated minuszerodegrees.net accordingly.

You're welcome, Just a small correction, I have the AMI bios (http://www.minuszerodegrees.net/bios/bios.htm) in my 5170 and 5162 and not the AWARD bios as i said previously, I tried the AWARD but then changed to the AMI bios a short time after.

itsvince725
April 17th, 2017, 07:51 AM
I suppose you could add a 3.5 floppy in a 5 1/4 to 3.5 adapter to the 1.2 Mb floppy using the fixing plates (if you have them), That's what i did until my 1.2 Mb died on me half way through writing to a floppy, Now i just have a 3.5" 1.44 Mb floppy in an adapter secured to the original HH frame. As for the second bay i removed the non-working MFM drive from the frame and have the frame secured in the bay with the drive activity LED wired up to the IDE controller. I currently have CF in mine with the XUB homed in a boot rom socket of a nic.

I have one plate on the frame holding the 1.2MB floppy drive, but I don't have a second plate or the frame that originally held the MFM drive.

Malc
April 17th, 2017, 10:42 PM
Worth posting in the wanted section on here, I'm sure somebody on your side of the pond must have a few doorstops they are willing to part with, Might get lucky and get fixing plates for the floppy drives too.

ibmapc
April 17th, 2017, 10:48 PM
...But note: When you remove the original MFM/Floppy controller from the XT 286 and replace it with a IDE controller, On boot up the IBM XT 286 bios throws a 601 error because it expects to find the original controller ...( Like the 5170 ).
I think it depends on the IDE controller. My 5162 has no issues at all with Kouwell model KW-557B.

Malc
April 17th, 2017, 11:41 PM
That's interesting, So you have the original IBM Bios, Are you using the XTIDE Universal Bios as well ?

ibmapc
April 18th, 2017, 06:47 AM
That's interesting, So you have the original IBM Bios, Are you using the XTIDE Universal Bios as well ?
Yes and Yes. I removed the original controller, installed the new one, ran GSETUP and set hard drive type to NONE. Then I installed an old rev 1 XTIDE just to use the EEPROM. I tried putting the EEPROM in the NIC but found it could not be written to there(had to pull the EEPROM and write to it in my Programmer) , hence the XTIDE R1, make updates to the XUB much easier at the expense of an 8bit slot. Works like a charm, using XUB R591.

Malc
April 18th, 2017, 08:08 AM
That's very strange, I tried all the controllers i had spare and got the 601 error every time and total corruption using the XUB, I swapped out the BIOS and no problems now, I wonder what the original IBM Bios looks for on the controller then ? :confused:

Have you got a 5170 with original IBM Bios and using the XUB ?

Edit: I just googled your multi i/o card and it seem's to be an EIDE card, I think i've got an EIDE card in another machine, I've got to find it now and try it, Dangit!!!

itsvince725
April 18th, 2017, 09:03 AM
Worth posting in the wanted section on here, I'm sure somebody on your side of the pond must have a few doorstops they are willing to part with, Might get lucky and get fixing plates for the floppy drives too.

Thanks for the suggestion, I did just that!

ibmapc
April 18th, 2017, 09:03 AM
AFIK It's just plain IDE not EIDE. Only thing I can think of is the IO ports for HD and FD need to be the same as Original IBM controller.

EDIT:
Did you have a floppy connected to your card or just the IDE. I seem to remember that mine thew that 601 error when the floppy was not connected.

Malc
April 18th, 2017, 10:37 PM
I had the floppy connected, Though the original 1.2 Mb floppy drive died on me when i borrowed it whilst the 5162 was waiting for rebuild, So i now have a 1.44 Mb 3 1/2" in there. I found that multi i/o controller i was thinking about but still got the 601 error, My 5162 works very well with the other bios and the XUB so i'll leave as is now.

modem7
April 19th, 2017, 01:11 AM
... I wonder what the original IBM Bios looks for on the controller then ? :confused:
Refer to [here (http://minuszerodegrees.net/temp/3/temp_864151976127264678541.png)]. When it came to detection of the 'IBM Fixed Disk and Diskette Drive Adapter' ("combo"), the BIOS code changed significantly after the first revision of 5170 BIOS.