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View Full Version : Does a 5 1/4 HD drive work on an XT?



NicolasF
July 22nd, 2006, 09:18 AM
I have a 5 1/4 HD floppy and it doesn't work in my XT, but I have tried a 3 1/2 HD and it works. Do I have to change any jumpers in the 5 1/4 drive to make it work?

mbbrutman
July 22nd, 2006, 09:30 AM
You would have to change the jumpers on any drive to make it work.

The only thing that 5.25 vs. 3.5 means is that the mounting options in the case are different.

Jorg
July 22nd, 2006, 02:10 PM
Funny enough I tried exactly this one hour ago, and I could not get it to work.
Haven't found any tweakable jumpers on that specific HD drive- I'll see if some other one I got has them

Terry Yager
July 22nd, 2006, 02:36 PM
There have been numerous discussions in these forums about the problems associated wlth uzing DD media inna HD drive & vicey-versey. I'm about half fit-shased right now, so I don't feel like looking it up myself, but a search of this website should turn up sum'n useful.

--T

mbbrutman
July 22nd, 2006, 03:08 PM
Sorry, I misread the post - I thought the poster was talking about hard drives.

Here is everything you wanted to know about floppy drives:

http://www.brutman.com/PCjr/diskette_handling.html

NicolasF
July 22nd, 2006, 03:40 PM
So... it seems like there is no way to make a High Density drive work on a PC-XT. :( I just have to find a working 5 1/4 Double Density...

dongfeng
July 22nd, 2006, 03:50 PM
if you have a 1986-dated BIOS, you can use 3.5" DD floppy disks (720kB) too! I haven't got a suitable drive so I haven't actually tested this.

dongfeng
July 22nd, 2006, 03:51 PM
I read that you can use a HD 5.25" drive in an XT, providing you use a suitable HD controller card.

Terry Yager
July 22nd, 2006, 04:12 PM
Well, yah...sorta. Some controllerz have thier BIOs extintions have on-board.

--T

NicolasF
July 22nd, 2006, 04:44 PM
I read that you can use a HD 5.25" drive in an XT, providing you use a suitable HD controller card.

Yeah... but it's imposible to get one of those controllers here... it's easier to find a double density floppy :)

NicolasF
July 22nd, 2006, 04:58 PM
check this out: http://www.jdr.com/interact/item.asp?itemno=MCT-FDC-HD4

Terry Yager
July 22nd, 2006, 05:39 PM
So... it seems like there is no way to make a High Density drive work on a PC-XT. :( I just have to find a working 5 1/4 Double Density...
...or a 3.5" 720K DD drive. (The 1.44 drives seem to work ok, but only at double-density).

--T

modem7
July 22nd, 2006, 10:05 PM
Here's the story as I see it:

There are two factors: hardware and software

DOUBLE DENSITY

The standard IBM controller provided in an IBM XT only supports double density. That means 5.25"-360K and 3.5"-720k
If you have the 9May86 ROM BIOS in your XT, then it will happily read/write both drives.
If you have an earlier ROM BIOS, to read/write a 3.5"-720k, you need to add a suitable DRIVER.SYS line in CONFIG.SYS

HIGH DENSITY

First, you will need to have a floppy controller that supports high density (from a hardware perspective).
Most third party floppy controllers that I've seen contain a BIOS extention and a set of DIP switches.
If you have one of those, you just set the switches and off you go.

If your floppy controller isn't of that type, you should be okay if you have the 9May86 ROM BIOS.
If you have an earlier ROM BIOS, you need to add a suitable DRIVER.SYS line in CONFIG.SYS

modem7
July 22nd, 2006, 10:13 PM
According to various sources, DOS is involved as well, ie.

1983 MSDOS 2.0 (released with XT, hierarchical file system, hard drive support, 9 sectors per track floppies [eg. 360 KB])
???? MSDOS 2.01 (2.0 with international support)
1984 MSDOS 2.11 (bug fixes)
1984 MSDOS 3.0 (released with AT, includes 1.2 MB [5.25 inch] floppy support)
1984 MSDOS 3.1 (support for Microsoft Networks)
1986 MSDOS 3.2 (720 KB [3.5 inch] diskette support)
1988 MSDOS 3.3 (1.44 MB [3.5 inch] diskette support)

Jorg
July 23rd, 2006, 12:37 AM
A bit off-topic maybe, but in my search for a 360KB Floppy drive, somebody offered me a Safronic DS-60A drive- but he is unsure if this is HD or DD.
Google does not give me anything- would someone here know this?

modem7
July 23rd, 2006, 03:15 AM
If you have one of those, you just set the switches and off you go.

Some also needed a special driver to be loaded in CONFIG.SYS - a driver supplied with the card.

Jorg
July 23rd, 2006, 03:28 AM
Some also needed a special driver to be loaded in CONFIG.SYS - a driver supplied with the card.

Both that and using driver.sys is a bit nasty if you want to use that drive as bootdrive