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Xacalite
August 17th, 2017, 12:23 AM
In IBM 5160, the BIOS dated 01/10/86 adds support for 720KB floppy drives.

I installed a 1.44MB FDD (for use with DD media, of course) in some late XT clone, one with that highly-integrated Faraday chipset.
It would be reasonable to assume that such a late clone has a BIOS with all the features of IBM's 01/10/86.

But there's a problem: by default DOS treats that FDD as a 360KB one, attempts to format a 720KB diskette (format /f:720) result with "Parameters not compatible..." error.
DRIVPARM solves the problem.

Does it mean that my BIOS lacks support for 720KB drives?
IBM 5160 with a late BIOS doesn't need DRIVPARM here, does it?

Using PC DOS 2000, if that matters.

DDS
August 17th, 2017, 01:46 AM
In IBM 5160, the BIOS dated 01/10/86 adds support for 720KB floppy drives.

I installed a 1.44MB FDD (for use with DD media, of course) in some late XT clone, one with that highly-integrated Faraday chipset.
It would be reasonable to assume that such a late clone has a BIOS with all the features of IBM's 01/10/86.

But there's a problem: by default DOS treats that FDD as a 360KB one, attempts to format a 720KB diskette (format /f:720) result with "Parameters not compatible..." error.
DRIVPARM solves the problem.

Does it mean that my BIOS lacks support for 720KB drives?
IBM 5160 with a late BIOS doesn't need DRIVPARM here, does it?

Using PC DOS 2000, if that matters.

IIRC, I needed the DRIVPARM command to get what you're doing to work in a late version IBM 5160. In fact, I was unable to use PCDOS 3.x or FREEDOS 7.x because they don't include the DRIVPARM command. One FREEDOS site mentioned deliberately leaving the command out because no one would actually ever use it. MSDOS 4.x, 5.x, and 6.x all work fine at this point.

It's been a while since I touched it, but I seem to recall having some trouble formatting 720k floppies and needing to sneaker-net them to an older machine running Windows 98. Be advised that some newer machines that have 1.44m floppies will not recognize a 720k floppy no matter what flags you specify. Some newer versions of Windows seem to alter the boot block of any floppy inserted into the drive. Then you get the mysterious "invalid media" or some such when you take your known good disk back to your antique system.

What you're trying to do is very workable. But there are a few bumps in the road. I think there's a how to on Modem7's minuszerodegrees.net site that I looked at as well. I'll look at my system a bit later today and verify what I did to get it to work and update this post accordingly.

-----------------

I wanted to check what I have currently running on my 5160 for a quick answer but instead found only another riddle. I'm pretty sure I used something like:

drivparm=/d:0 /c /h:2 /s:9 /t:80

in config.sys to get the system to treat a 1.44m drive as a 720k. But upon checking the MSDOS 6.22 boot floppy currently in the 1.44m drive hooked up as drive A:, and the root directory of the CF card acting as drive C: I find no config.sys on either one. Yet the system will boot up off of either and the A: drive will read a 720k floppy. But I do recall moving up from PCDOS 3.x that came with the machine specifically because that system didn't have the DRIVPARM command. I tried but didn't stay with the DRIVER= command because IIRC it assigned the 720k drive a different drive letter. All I had at that time was MSDOS 5.x on 360k floppies, MSDOS 4.x on 720k floppies, and an MSDOS 6.22 upgrade set on 1.44m floppies. I had managed to get bootable 720k floppies built of all three versions, and the system booting off of a CF card resident version of each before life pushed the project, not to the back burner, but completely off of the stove. Logic tells me what I have should not be working but it is. The only variable I can't quickly account for is, could the system now be happy with an A: drive that's a Sony 1.44m masquerading as as 720k due to the addition of an XT-IDE card? The XT-IDE in the system is a Glitch Works rev3 card (which works like a champ by the way). Upon restart, the system comes up into the BIOS resident on the XT-IDE card and allows you to select the boot device. So I'm not using a plain vanilla IBM 5160 boot process at the current time.

Trixter
August 17th, 2017, 10:33 AM
I had to use format /t:80 /n:9 to get formatting to work, and "DEVICE = DRIVER.SYS /D:1" in config.sys, to get a 720K drive working in my 6300.

Malc
August 17th, 2017, 09:50 PM
Search archive.org for " setdrive " and try that.

alecv
August 18th, 2017, 12:08 AM
Try floppy drive TSR like
800.COM
http://cd.textfiles.com/pcmedic/utils/floppies/800ii140.zip
or PU_1700
http://nostalgy.net.ru/disk/1700full.zip

vwestlife
August 18th, 2017, 04:54 AM
Just use SETBPB35 -- it's easier and doesn't take up any RAM:

ftp://ftp.oldskool.org/pub/tvdog/tandy1000/misc/setbpb.zip


This program will set the device characteristics for the A or the B diskette drive to indicate that the drive is a 720K drive instead of a 360K drive. It requires DOS 3.2 or later.

The only command line parameter is the drive letter (A or B).

For example, to indicate that your B drive is a 720K 3.5" diskette drive:

SETBPB35 B

Xacalite
August 18th, 2017, 05:15 AM
OK, but I don't need all those solutions - as I already stated, DRIVPARM solves my problem and doesn't take up any RAM.
I just want to know if this problem means that my BIOS is retarded compared to IBM's 01/10/86.
Anybody has a 5160 with BIOS dated 01/10/86 or later, with a 720KB (or 1.44MB connected to the standard, non-HD controller) drive? Please see if formatting 720KB floppies just works, without the need for DRIVPARM/DRIVER.SYS/other such tools.

Chuck(G)
August 18th, 2017, 08:12 AM
As long as you don't need to format disks in your system, it doesn't matter. The BPB from the boot sector is used for reading and writing.

Formatting can be done with a third-party formatter without any CONFIG.SYS changes.

Stone
August 18th, 2017, 08:34 AM
Formatting can be done with a third-party formatter without any CONFIG.SYS changes.Like FormatQM? :-)

Chuck(G)
August 18th, 2017, 09:02 AM
Or, if you want to go more retro, ConFormat... :)

Stone
August 18th, 2017, 10:14 AM
Silly me... I forgot that one. My bad. :-)

Malc
August 18th, 2017, 10:22 AM
...Anybody has a 5160 with BIOS dated 01/10/86 or later, with a 720KB (or 1.44MB connected to the standard, non-HD controller) drive? Please see if formatting 720KB floppies just works, without the need for DRIVPARM/DRIVER.SYS/other such tools.

Yes formatting a 720K in my IBM XT with the 01/10/86 bios works fine, Using original IBM XT floppy controller with 1.44Mb drive attached, No 3rd party tools required.
The 11/08/82 IBM Bios see's the drive as a 360K so needs 3rd party tools to format properly, I use Setdrive.

Xacalite
August 19th, 2017, 09:55 AM
OK, so the conclusion is:
The BIOS in this clone, dated 11/15/88, of unknown origin (the only string in ROM that can be maker's ID reads "Star H."), is inferior compared to IBM's 01/10/86, in the floppy support area.
Oh well, I can live with this. EOT.

arteq
July 29th, 2018, 09:31 AM
OK, so the conclusion is:
The BIOS in this clone, dated 11/15/88, of unknown origin (the only string in ROM that can be maker's ID reads "Star H."), is inferior compared to IBM's 01/10/86, in the floppy support area.
Oh well, I can live with this. EOT.

do you have picture of mentioned mobo ?

SpidersWeb
August 1st, 2018, 05:22 PM
When you add an 80 track drive to an IBM PC XT with the 86 BIOS... does it do a seek test to identify the drive type (or another test), or does it just assume it's 360KB like every other XT BIOS out there?

Mine doesn't seem to do anything special to identify drives, so I wondered what the "720KB support" actually was.