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JT64
November 11th, 2008, 10:35 PM
1. I do not recall if the 3.5 floppyreader in my XT did support formating both 360 and 720, does anyone know. Does it suppot DD(720?)

2. Is there any modern USB floppy reader that support formating older formats like 360 and 720?

3. Is there support for formating 720 and 360 disks in bios on modern computers, or is it solely dependent on software?

I know HD discs could be used if you pluged the right wing. (But they would not hold data for long.
I see no separate controller for the floppy i guess it is onboard motherboard.

JT

Terry Yager
November 11th, 2008, 10:54 PM
:confused:...???

--T

JT64
November 11th, 2008, 11:26 PM
Maybe strange question i have the XT but no floppies, i have a new computer but no floppy reader. Leaves me in shadowland, have not bought that CF memory yet.

JT

JT64
November 11th, 2008, 11:29 PM
When i finally get the CF i have to download img, since there is no emulation of Floppy in DOS i need to copy them to a floppy. Would be nice to know what *HARDWARE* formats of images my XT handles.

Could be SS DS DD.

JT

Terry Yager
November 11th, 2008, 11:42 PM
Still don't get it. What is your question?

--T

JT64
November 12th, 2008, 12:27 AM
Still don't get it. What is your question?

--T

1. Is there a modern 3.5 floppyreader/writer (preferably USB) that support formating of 360 and 720 kb (DD) disc?

"I guess it is related to the reading writing hardware as well as bios and software"

2. I am not sure what type of 3.5 floppyreader reside in my original XT, i have not floppies to check. I only know that it is an original ITT Xtra professional, i think it support both 320 kb and 720 kb formatted floppies.
It will not support 1.44 MB formated floppies.

Do anyone know what floppy formats supported?

JT

BG101
November 12th, 2008, 12:44 AM
Formatting is done by software, the actual drive type is set in the BIOS. AFAIK all 1.44Mb drives will format at 720K, USB drives should be no different. Not heard of a 3" drive supporting 360K though! This is DD 5" format.

The XT drive will almost certainly be 720K.



BG

JT64
November 12th, 2008, 12:57 AM
Formatting is done by software, the actual drive type is set in the BIOS. AFAIK all 1.44Mb drives will format at 720K, USB drives should be no different. Not heard of a 3" drive supporting 360K though! This is DD 5" format.

The XT drive will almost certainly be 720K.



BG

Well on my ATARI they shure did, i think it was called SS single sided and DS double sided. So pc only have the DD double density and HD high density formats?

JT

BG101
November 12th, 2008, 01:33 AM
DD and HD for the 3" disks, as far as I'm aware, and DD, QD and HD for 5" (360K, 720K and 1.2Mb)

.. plus a few others which may or may not be supported, depending on the drive itself, the floppy drivers and the software.

It's worth experimenting with different formats to see what works but you'll need to use DD disks.

The drivers I have installed on my main (XP PRO) PC support all manner of formats (141 different ones for 3" and 131 for 5") :D

I formatted a few disks with various capacities as an experiment and my other machine (Win ME) wouldn't read the single-sided disks, though haven't checked yet whether that's down to the OS (drivers) or the FDD controller. This does suggest that SS disks weren't supported, at least with later versions of Windows.


BG

dr.ido
November 12th, 2008, 04:33 AM
The 3.5" FDD in your ITT XT is most probably a 720KB DSDD drive. If a DSDD 3.5" floppy is formatted 360KB it usually means the machine isn't set up correctly and is treating the 3.5" floppy drive as if it was 5.25" 360KB drive. I do remember having more than one XT setup where if the approriate DRIVPARM line wasn't present in CONFIG.SYS it wouldn't recognise the 3.5" floppy drive correctly. Even my IBM JX (equipped with 3.5" DSDD drives from the factor) required DRIVPARM/DRIVER.SYS depending on which version of DOS it was.

Single sided 3.5" floppy drives exist, but I don't think they were ever used in a PC-XT system.

Some controller cards will run a 1.44MB DSHD 3.5"" floppy drive in a XT, but if you had one you would probably already know it.

I assume that you are looking for a USB floppy drive that can read/write 720KB DSDD disks.

Not all USB floppy drives can read/write 720KB DSDD discs. I've only ever owned one USB floppy drive, so I can't offer many suggestions.

The one USB floppy drive I did have was an Imation LS Superfloppy drive. If you used the Windows supplied drivers it only supports 120MB LS-120 discs and 1.44MB DSHD discs. If you used the older Imation drivers it also supported 240MB LS discs, 1.2MB Mode 3 DSHD discs and 720KB DSDD discs.

It also had a weird option to format a standard 1.44MB DSHD to 32MB, but such discs could only be read/writen with Imations software, not directly.

Chuck(G)
November 12th, 2008, 08:52 AM
The one USB floppy drive I did have was an Imation LS Superfloppy drive. If you used the Windows supplied drivers it only supports 120MB LS-120 discs and 1.44MB DSHD discs. If you used the older Imation drivers it also supported 240MB LS discs, 1.2MB Mode 3 DSHD discs and 720KB DSDD discs.

The Imation drive is a special case, and as you note, was made primarily to handle the special high-capacity diskettes. (I've got the drive in IDE and SCSI variants).

But if we're talking about generic inexpensive USB floppies, almost all will handle 720K DSDD; many will not handle 360K SSDD. And all require that the information be written using normally-IDed 512 byte sectors.

A benefit of most USB floppy drives is that they will read and write (but not format) 1.23MB "DOS-V" 1024-byte sector diskettes also--something that your average legacy 1.44MB drive will not do.

To understand why this is, consider that the protocol used to talk to the drive resembles the SCSI command set. In other words, relative block (not CHS) addressing is used. The USB drive which is a bit limited in smarts, must be able to compute the physical address of any sector simply by reading the first track on a diskette. To do this successfully, it makes a lot of assumptions about the format.

barythrin
November 12th, 2008, 09:47 AM
I just tried with a TEAC* (note: didn't realize it was Dell badged) USB Floppy drive we have at work via Windows XP (format b: /t:80 /n:9) and it reported the parameters were not supported by the drive.

I'm honestly surprised, I thought it was gonna be ok but nope. I used to like TEAC for their cdrom abilities to read improperly formated CDs but guess I'll have to rethink them as a preferred vendor.

- John

Chuck(G)
November 12th, 2008, 02:06 PM
I just tried with a TEAC USB Floppy drive we have at work via Windows XP (format b: /t:80 /n:9) and it reported the parameters were not supported by the drive.

I'm honestly surprised, I thought it was gonna be ok but nope. I used to like TEAC for their cdrom abilities to read improperly formated CDs but guess I'll have to rethink them as a preferred vendor.

If you want to rethink preferred vendors, then reconsider Microsoft. I just plugged a Teac MP05U into a system running Win2K. It formatted a DSDD diskette very nicely using FORMAT x: /F:720, where x: is the drive letter. I suspect that it would do the same under Win9x.

Microsoft unnecessarily took a meat axe to a lot of floppy features in XP.

MikeS
November 12th, 2008, 03:24 PM
I'm confused; are you guys talking about 5.25 or 3.5 disks?

AFAIK XP will format any PC standard using /T and /N (Not /F), but maybe the USB processor doesn't like those?

Chuck(G)
November 12th, 2008, 09:46 PM
I'm confused; are you guys talking about 5.25 or 3.5 disks?

AFAIK XP will format any PC standard using /T and /N (Not /F), but maybe the USB processor doesn't like those?

Do you know of a 5.25" USB drive?

But you're right about the 720K--XP formats the diskette just fine with /n:9 /t:80 on a Teac USB drive. As a matter of fact, I can specify /n:8 /t:77 to get a 1.23MB format with 1024 byte sectors--you can hear the drive change speed.

So, I don't know what's happening with Barythrin.

FWIW, my Teac drive is labeled "SmartDisk", model FDUSB-TM2 and is identified as an Teac FD05PUB drive by WinXP.

MikeS
November 13th, 2008, 06:48 AM
Do you know of a 5.25" USB drive?


---------
Umm, no; lotsa folks'd like one though.

But talk of an ITT XT, 360K capacity and 'preferably USB' was confusing...

wmmullaney
November 13th, 2008, 07:38 AM
I have a VST tech floppy drive that seems to work fine with 360 discs. Model fdusb.

Chuck(G)
November 13th, 2008, 08:49 AM
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Umm, no; lotsa folks'd like one though.

But talk of an ITT XT, 360K capacity and 'preferably USB' was confusing...

I still don't know what was being referred to there. I know of at least three "360K" 3.5" layouts.

The first is simply to use the first 40 cylinders, double-sided. I consider that to be cheating, since the layout is really the same as the 720K variety.

The second is single-sided, 80 cylinder. I know of no arguments under XP format to get that one literally formatted, though simply ignoring the second side of a double-sided 720K format essentially does the same thing.

The third is 40 cylinder, double-sided, with the cylinders spaced at 67.5 tpi as seen in some early 3.5" disks, particularly the 600 RPM ones. I know of no USB drive that will handle that one.

Many USB drives use a Teac FD05U drive, just adding a cable and enclosure, regardless of what the brand is on the nameplate. It's easy enough to tell by looking to see what XP device manager reports.

barythrin
November 13th, 2008, 11:32 AM
Ah true.. yeah I was testing Windows XP pro sp2 and just noticed my "teac" (model: FD-05PUYB-1374) is actually a Dell USB floppy, even though it's really TEAC. So.. Dell who loves to (in their infinite wisdom) reflash EPROMS on their cards and break features did get ahold of it. So I need to update my comment to say a Dell USB floppy of this model number and under XP doesn't appear to support 720K 3.5" formatting via the /n /t method.

And yes you're right, it'd likely work fine under 2000 which DOES support the regular format.com commands opposed to the neutered XP version of format. Just for the record I did cover the hole on the floppy during the test so it'd think it was a 720K and be happy.

BG101
November 13th, 2008, 03:06 PM
---------
Umm, no; lotsa folks'd like one though.

But talk of an ITT XT, 360K capacity and 'preferably USB' was confusing...This is something I'm tempted to have a go at building. Would it take much more than stripping the interface from a 3" USB drive caddy, installing it in a 5" one and fitting a suitable connector and drive? Apart from modifying the drivers of course, to provide the appropriate drive parameters.

Or will a USB FDD interface simply not work with a 5" drive.




BG

BG101
November 13th, 2008, 03:09 PM
Do you know of a 5.25" USB drive?
Umm, no; lotsa folks'd like one though.Me too.

This is something I've been thinking about for a while.

I'm tempted to have a go at building. Would it take much more than stripping the interface from a 3" USB drive caddy, installing it in a 5" one and fitting a suitable connector and drive? Apart from modifying the drivers of course, to provide the appropriate drive parameters.

Or will a USB FDD interface simply not work with a 5" drive.




BG

Chuck(G)
November 13th, 2008, 05:41 PM
Me too.

This is something I've been thinking about for a while.

I'm tempted to have a go at building. Would it take much more than stripping the interface from a 3" USB drive caddy, installing it in a 5" one and fitting a suitable connector and drive? Apart from modifying the drivers of course, to provide the appropriate drive parameters.

Or will a USB FDD interface simply not work with a 5" drive.


Well, if you take a look at a 3.5" USB drive, you'll see that the USB controller and the FDC for the drive are rolled into a single chip. It might be possible to use the PCB from a 3.5" drive on a 5.25" frame, but I wouldn't want to try.

When USB floppies first made their appearance, the USB/FDC part simply interfaced into a legacy 34-pin floppy interface. But they were never very common and I haven't seen one of those in a very long time.

Probably better to use a dedicated μC and an FDC chip to provide the USB interface to any legacy drive. Something akin to the Microsolutions Backpack parallel-port floppy--just had a 82077, some DRAM and an 8051-family controller in the box. It was a good idea--you could have port-level access to the FDC via the parallel port.