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Routes to get my XT an OS

S

sqpat

Experienced Member
Joined
Mar 21, 2009
Messages
168
Location
Seattle, WA
Well, I'm in a bit of a predicament with my XT. I believe I've finally got a working hard drive and it's runs its POST checks and gets no errors, but it's got the old BIOS, I'm lacking a 5.25" floppy that I can use to boot or install an OS from (or any other computers to write 5.25" media)... so basically by XT is as useful as it was when i first got it - just a BASIC interpreter!

There are several routes i can take with trying to get my XT bootable into DOS or something, and I was wondering if anybody could think of any others, or maybe save me some pain and let me know which way might be most worth my time.

1. Just buy some early version of DOS online and install dos.

2. Get another older, working machine that i can use to create some 5.25" floppies

3. Get some soldering tools, a ROM programmer, a chip, and replace the BIOS with the newer revision so that I can use 3.5" floppies instead (which are more readily available to me)

4. Get a high density 5.25" floppy drive that might make life a little easier

5. Same as above, but with a serial external floppy drive. Can a serial port drive boot in an XT, and can I use it in a modern PC with a serial port if it might not have BIOS support?

It's been a long 3 months and I'm slowly getting this thing into working order, but it seems this last hurdle is the most irritating one.
 
any chance you can fit the MFM controller + HDD in something like a, say, 486?
 
sqpat said:
There are several routes i can take with trying to get my XT bootable into DOS or something, and I was wondering if anybody could think of any others, or maybe save me some pain and let me know which way might be most worth my time.

1. Just buy some early version of DOS online and install dos.

2. Get another older, working machine that i can use to create some 5.25" floppies.
Click to expand...

The first two options would be the easiest. In response to your other post about DOS 3.30, it certainly was distributed on DD disks.
 
In you case I'd buy some blank 360k (NOT 1.2mb) disks and hook your XT's drive up to a system with OS/BIOS support for 360kb drives. Copy all the critical things to your XT in this way. Then I'd get an NIC with an RJ45 port that works in an 8-bit slot. After you get file sharing going you won't need to steal the 360k drive anymore.
 
A 1.44MB or 720K 3.5" drive will work fine at 720K in a 5150. You can even image-copy a 360K disk to a 720K and it will boot in an XT fitted with a 3.5" drive. After you get DOS installed, you can use DRIVPARM in your CONFIG.SYS file to tell DOS to treat the drive as a 720K instead of 360K.

The principal difference in format between a 360K 5.25" adn 720K 3.5" drive is the number of tracks--a 720K has twice the number that a 360K does.
 
I'm about 60 miles south of you. If you're game, you could bring your XT over to my place and we could hook up a working 5.25" drive and get an OS installed on your system. Send me a PM if you're interested.
 
Jorg - regardless, if the drive ends up actually not working (who knows at this point!) that might end up being a good solution

strollin - i'll consider that offer if nothing else looks promising. The only real problem is that it'd leave me pretty inflexible with my current setup. That is, if just about anything broke (floppy drive, HDD, etc) i'd be pretty much unable to fix it myself since i'd be reliant on the working XT for everything.
 
If you got a more recent ISA floppy drive controller (don't matter if it's a 16-bit card), you can actually use a 720Kb disk and a HD drive to boot your system. However, in order to use 1.44Mb disks, you'll have to either replace the BIOS (as you suggest in your post) or find a driver that'll configure the drive.

It won't really matter since you'll be able to boot anyways.
 
per said:
If you got a more recent ISA floppy drive controller (don't matter if it's a 16-bit card), you can actually use a 720Kb disk and a HD drive to boot your system. However, in order to use 1.44Mb disks, you'll have to either replace the BIOS (as you suggest in your post) or find a driver that'll configure the drive.

It won't really matter since you'll be able to boot anyways.
Click to expand...

Recent, nothing. I can show you a 720K drive working on the original 5150 controller. What's the basis for saying "recent" ISA floppy controller?
 
Chuck(G) said:
Recent, nothing. I can show you a 720K drive working on the original 5150 controller. What's the basis for saying "recent" ISA floppy controller?
Click to expand...

Because then you can use a 1.44Mb drive and 1.44Mb disks formated as 720Kb disks. You will also be able to use a 1.44Mb drive to write the disks.

By using the original controller and a 720Kb drive, you MUST use a 720Kb drive to write the disks.
 
per said:
Because then you can use a 1.44Mb drive and 1.44Mb disks formated as 720Kb disks. You will also be able to use a 1.44Mb drive to write the disks.
Click to expand...

I think what we're getting at is the fact that the original IBM controller uses disk drives with an edge connector. You couldn't simply use a common 1.44MB floppy with a pin connector.

Real 720k drives with edge connectors are hard to find, and every one I've seen on Ebay is outrageously priced. Or you could get an external drive like this 4865:

http://cgi.ebay.com/IBM-4865-EXTERN...66:2|39:1|72:1205|240:1318|301:1|293:1|294:50

This one is the version for the XT with the square power plug. I've wanted one myself, but I've never been able to find out how to connect the plug (some kind of adapter?). Google turns up almost nothing.
 
The only time you'll run into problems using a 1.44M drive on a legacy 5150 controller is if it's one that uses pin 2 for a density select. This is definitely not the case with almost all 1.44M drives (some PS/2-style drives ignored the aperture)--they use the media aperture to determine density.

Of course, to use one, if all you have are 1.44M floppies, you'll have to cover over the density aperture. No big thing.

As far as cable, find one of the 80's era cables that still had edge connectors for 5.25" drives, but a 34-pin header for the controller connection (my hellbox is full of them). Put the edge connector with the "twist" on the controller and stick the header onto the 3.5" drive. You'll need an adapter for the power connection, but that's not a big thing either.
 
EDIT: Okay, I misread. I'm going to try some of that with my multifunction card or the standard ibm floppy card, then.
 
in the midst of trying my 3rd separate 1.44 MB floppy drive right now, connected to the multifunction card with a standard floppy cable... covering the density hole on some 1.44 MB floppies, and both trying "FORMAT A: /T:80 /N:9" or winimage's 720 KB floppy format methods. I can see the disk as a 720 KB formatted floppy in win XP. I can hear seeking noises from the floppy on the XT at startup, but thats all i get out of it. It never manages to actually boot. Any idea if there's something I might be forgetting?

ADDITION: I actually tried a straight up 720 KB disk as well. No luck.
 
sqpat said:
in the midst of trying my 3rd separate 1.44 MB floppy drive right now, connected to the multifunction card with a standard floppy cable... covering the density hole on some 1.44 MB floppies, and both trying "FORMAT A: /T:80 /N:9" or winimage's 720 KB floppy format methods. I can see the disk as a 720 KB formatted floppy in win XP. I can hear seeking noises from the floppy on the XT at startup, but thats all i get out of it. It never manages to actually boot. Any idea if there's something I might be forgetting?

ADDITION: I actually tried a straight up 720 KB disk as well. No luck.
Click to expand...

No, no, no!

You can't use the version of DOS supplied within Windows XP's format command. It's to new and it uses 286 or 386 codes. You'll want to make a startup disk of a version of DOS before 6.22.

What image are you trying to write to it by using WinImage?
 
per said:
No, no, no!

You can't use the version of DOS supplied within Windows XP's format command. It's to new and it uses 286 or 386 codes. You'll want to make a startup disk of a version of DOS before 6.22.

What image are you trying to write to it by using WinImage?
Click to expand...

No no,. Im using a pc dos 3.30 disk, not the win XP boot image. Im just formatting a blank disc from within XP, from the command line with the FORMAT command. I copy files to it afterward, or with WinImage. Diskettes i was formatting under linux in "ms-dos format" seemed not to show up as 720 KB under windows.


One thing i've noticed is some of the pins are different. Of these 3 drives, one has all the pins, one is missing pin 2, the other is missing all but 4 on the first row. Might one of these be more likely to work than the others?
 
Well, I really think I've exhausted the 720 KB floppy route, at least with 1.44 MB drives. The XT has beaten me into the ground once again, and I'm beginning to consider the BIOS upgrade. If I ask someone to send me one and get a small soldering set, that'd be a fun little project. The other alternative is the 60 mile drive.
 
If I have been following you correctly, you are trying to read/write a 720kb disk on an XT with a 1983 BIOS? This isn't going to work unless you run DRIVER.SYS or DRIVPARM

You'll need a line like this in your config.sys
device=driver.sys /d:1

Otherwise your 720kb drive will only be able to read/write 360kb disks.
 
Thanks to some help from Chuck(G) i was able to get a 720 KB floppy to boot! Unfortunately, the good news ends soon after as I can't get fdisk to to format the MFM drive; there's an error reading the fixed disk.

I don't know that this necessarily means a problem with the drive itself; i had an original XT drive in here first which caused some kind of POST error, so I sent for this one, which is 30 MB and came from an AT. This one doesn't throw any POST errors, but I don't know that it necessarily means the drive works. I was thinking that perhaps the original IBM XT hard drive controller doesn't recognize the AT hard drive... i don't see any jumpers on the card, and I don't think the xt motherboard has anything related to the disk... hmph. If i can't get this working then maybe I'll be waiting for the 8-bit IDE card.
 
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