IBM 5162 XT-286
These are some notes on an IBM XT-286 PC that I have been refurbishing.
When I got this PC it had an old MFM hard drive in it and I could not get it to work. I took it out and set this system up with two 5-¼” floppy drives and DOS 3.3. But since it is an XT class machine (I later learned it is an AT) I wanted it set up with a hard disk. I had another PC class machine in my basement that had a Seagate RLL drive and controller in it so I thought I would try to move this over to the XT-286 to see if this could become the hard drive for this old IBM PC.
This old IBM PC also had a multi-I/O card in it and I had to figure out how to disable the hard drive on that controller so that the Seagate controller could be in control of the hard drives. The floppy drives remain on this Multi-I/O controller.
I installed the Seagate controller and the hard drive. At first I got nothing but errors. I tried swapping the card to another ISA slot. Eventually I got the Seagate controller to be recognized and the Seagate BIOS reported to the screen. I ended up installing the card in the slot closest to the power supply.
The hard disk was recognized as drive C by the Seagate BIOS but I could not at first figure out how to format it. I tried using the format routine on the Check-it disk. That didn’t work. I used the IBM AT Setup program and added the first drive to the setup. But I could not get FDISK to recognize the disk.
I did some reading on Google and found out that most MFM/RLL drives from the era of this XT-286 needed to be low-level formatted using the DEBUG routine. I had never done this before so I struggled to understand what needed to be done. Finally, I found the instruction sheet for the Seagate ST11M/ST11R controller, which is the controller I have. Those instructions said the drive came pre-formatted and had the setup program already installed on the disk. Well, that might have been the case when new but this disk was no longer in that same condition. The instructions also included how to use the DEBUG routine to format the drive. So, I read and re-read the instructions and gave it a try. Here’s what I did:
Made sure CMOS was set to “No Hard Drive”
Booted DOS 3.3 diskette
Started DEBUG (which was found on second DOS floppy)
At the “-” prompt I typed: G=C800:5
The Seagate controller routine took over and stepped me through the setup and format process. I entered correct drive parameters and the bad sectors from the disk label.
On the first attempt I got an error message of “Bad Drive !!!”. I rebooted, and this time the Seagate Format routine started on it’s own. I did not need to type Debug. Again, I entered the drive parameters and the bad sectors. The format started again, and again it ended in an error of “Bad Drive !!!” I again rebooted and I ran the format routine once again. This time it finished with success! The low-level format was completed and I was asked to reboot and run FDISK and FORMAT.
I rebooted with the floppy. I ran FDISK and this time FDISK found the drive and I was able to partition it as a single DOS drive. Next, I rebooted and ran FORMAT, using the command:
Format C: /s
This formatted the hard disk for DOS and added the DOS 3.3 command file to the root partition of the hard disk. I then rebooted again, this time without the floppy disk. The DOS system booted correctly to the C: drive. Success! I now have a hard drive on the XT-286.
To review:
These old PC’s that use MFM/RLL drives require that the drive be low-level formatted on the PC that the hard disk is installed in.
A controller card is installed in the 8-bit ISA slot. I used the slot closest to the power supply but I’m not sure it matters which slot. Make sure to disable any other hard disk controller cards.
Use DEBUG to start the formatting routine from the controller card. This is usually done by entering the “G=C800:5” command at the DEBUG prompt. But the address of the controller card could vary. C800 is the default for these old PC’s.
Once the low-level format is completed you use FDISK and FORMAT to set the drive up for use with DOS.
[Now that I have completed this exercise I think I can try to get the original MFM hard drive working using these same techniques. That drive may still work I just didn’t know how to format it.]
After I had the hard drive working I decided to reset the Multi-I/O card to use only the inputs I needed. This card is used for the floppy, LPT2, COM1, and the Game Port. There was also a second I/O card that I removed because I really didn’t need more than one or two serial and parallel ports.
I struggled to get the jumpers setup correctly since the instructions were rather cryptic. I decided to try different jumper settings and test the card to find out what the settings should be. After a few tries I was able to set up the card to work with one COM port, one additional LPT port (the PC already had one LPT port on the video card next to the Mono port), and the game port and floppy controller. I disabled the hard drive controller.
This PC is now working normally, with the C: drive, the A: 5-¼ 1.2M floppy drive, a serial port, two parallel ports, a game port, and the keyboard and CGA monitor. I have it connected to a 486 computer using Laplink on the COM2 port. It is running IBM DOS 3.3.
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04/25/20
The computer has been running fine and I usually just boot from the hard drive and run DOS. But I’ve been playing with CP/M-86 recently and I wanted to see if I could boot CP/M-86 on this computer. It won’t boot from the floppy drive A: - a 1.2M 5-¼ “ drive. I have been able to boot from this disk in the past as indicated in the text above. But now it won’t boot anything from A:. I get two beeps after the memory check and then I can hit F1 to boot. The floppy drive spins and the light comes on but it won’t boot from a floppy. I’ve tried several floppies that I know are bootable.
If I take the floppy disk out and reboot it works from the hard drive.
I wonder if I have a CMOS problem. But I can’t figure out how to run the CMOS Setup program without booting the Setup and Diagnostic Disk from floppy. I did run Gsetup from the hard drive and took a look but there does not appear to be any way to change boot parameters.
I was thinking maybe I will swap in a 3.5” floppy. But I still have to run setup.
I put in a floppy then power on, after the memory test, I hear two beeps. Then I touch F1 and I hear another beep and the floppy drive is accessed and the light is on, then it times out and I hear another, higher tone beep. The computer hangs and there is a single blinking line in upper left corner. If I hit the enter key I hear another of the higher tone beeps. I cannot continue to boot unless I use Ctrl-Alt-Del or power down. If I take the floppy disk out of the floppy drive, then reboot, then I still get the two beeps, then I hit F1 and hear another beep, then the floppy is accessed and the light comes on, then the hard drive light comes on and the system boots off the hard drive to the C:\> prompt.
I read in a service manual that the 5162 supports 3.5” drives but it may not work for booting, supporting only the 5.25” as drive A: and 3.5” as drive B:.
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10/3/21
I recently acquired a Tandy 1000HD that I would like to use with my only CGA monitor (The Goldstar 1410 Plus). So, I want to put this XT/286 back into Mono mode and use it with a Mono monitor. I have an IBM 5151 monitor and was hopeful that I could get it to work since that would keep it all “IBM”.
I opened the case but I could not remember what the cards were. I could see the CGA card that I had the Goldstar hooked up to. But I wasn’t sure if I had the Mono port I needed. There was a card with a label that said “Beltron” but I could not find any information about it. I read enough on the internet to guess that it was the Mono card, with a built-in Parallel port. It may be a Hercules also? Anyway, I put it back in and hooked up the 5151. The computer booted and the screen came alive, but it was not readable. Just a green blur and no readable text. I also tried this 5153 on the Tandy 1000HD with the same result. (Although the Tandy is set for CGA and I’m not sure this monitor will respond to that}. Anyway, it seems this screen is bad.
I hooked up another mono screen, from my Leading Edge PC, and rebooted the XT/286. It worked. But after the boot I noticed that I have the autoexec.bat set to CO80 to support the CGA monitor. I will need to change that. I also noticed that the SW1 switch on the motherboard is set to the rear, which is Mono mode, even though I have been using the CGA monitor. Maybe it doesn’t matter. But I will leave it set to the rear and then change the autoexec.bat to remove the color support.
I put in the Diagnostic and Setup disk and rebooted. I got errors and was asked to Hit F1 to continue. I hit F1 and booted from the floppy. I ran the Setup program and set everything up including setting to Mono. I rebooted and got a Floppy drive error. I ran diagnostics and the program seemed to find everything fine and everything looked ok. I quit the diagnostics and removed the floppy and rebooted. I again got a floppy drive error but I put the DOS 3.3 floppy disk into the drive and hit F1. It booted to DOS. I edited the autoexec.bat file on the hard drive and then took out the DOS floppy and rebooted with Ctrl-Alt-Del. I again got a floppy error but I hit F1 and it booted to the C: drive and this time the video mode is set correctly to Mono.
I shut down and took out the CGA card and then closed up and rebooted. Everything seems to be working fine except I still get the floppy error at startup. When I hit F1 it boots fine. So, I just have to use F1 to boot. It’s probably a missing termination on the floppy. But unlike when I was setting up CP/M-86 it is booting from floppy. This floppy is a 1.2M and it is supported in the IBM BIOS. But maybe it has trouble with 360k diskettes or other low-density formats. I’ll need to experiment more.
So, as of today (10/03/21) this is a working system with a Monochrome monitor.
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