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360kb floppy in modern pc: part 2

C

cfenton

Experienced Member
Joined
Jan 25, 2008
Messages
70
Okay, I was curb-shopping the other day during trash-day and snagged a Dell L733r (P3 733, 384mb ram). Booted it up, and lo and behold, it supports 1 360kb 5.25 disk. I plug in the the drive, and no luck, however. DOS doesn't give me any errors on boot-up, however, but whenever I try to read from the disk it says: Not ready reading drive A: Abort, Retry, Fail?

Here is my setup:

A floppy cable with a 34-pin female connector on one end, and 2 card edge connectors on the other (no twist in between). It was pulled from a working Kaypro 2'84.

A generic 360kb 5.25" floppy drive from ebay, no model number/company as far as I can tell. It has a jumper to choose the following settings: DS0, DS1, DS2, DS3. The disk drive is currently on the last card-edge connector, and it is jumpered to DS1 (DS2 gives an error, but DS3 works just like DS1).

Whenever I try to read drive A: in DOS, the status LED on the disk drive turns on, but nothing happens. Additionally, the disk spins up during boot-up, but never spins up once DOS is booted.

Finally, the environment is the version of DOS that ships with the windows 98 SE boot disk.

Any advice regarding jumper settings, cable positions (i think I read somewhere about someone trying to cover up pin 34 on the cable for some reason?), proper DOS settings, etc. is welcome.
 
I re-jumpered to DS0, and no difference. Does position on the cable matter (it's currently at the end)? The status light turns on when I try to switch to that drive, but it still gives me the "abort, retry, fail?" error. I believe the disk in the drive is a 720kb disk, but I didn't think that would make a difference.
 
Ok, twisted cables, all drives set to the second jumper location (if the choices start at DS0, then you want DS1, if they start at DS1, you want DS2).

Non-twisted cable, one drive set to DS0 (see above) and one drive set to DS1 (see above)

DS0/DS1 is going to be your A: drive. DS1/DS2 is going to be your B: drive

You don't say if you have another drive in the system and, if you do, this can cause problems, especially if it is a 3.5 inch drive.

Some 5.25 drives need the MS/MM switched to whatever it ISN'T at the moment
 
The 5.25" drive is the only one on the chain (the BIOS only shows support for one drive). What does MS/MM mean? The drive can be jumpered to be DS0, DS1, DS2, or DS3 (currently jumpered as DS0)
 
Sorry, reading back on that, you wouldn't have the slightest idea if you hadn't grown up with 5 1/4 inch drives.

MS/MM is another set of jumpers on the board somewhere. If they having staking pins, you're in luck and changing the jumper to the other (MM to MS or vice versa) might fix the problem. If they are hard linked, well, how good are you with a soldering iron?

Regardless, if it is the only drive on an untwisted cable, it has to be set to, in your case, DS0.
 
I'm actually extremely handy with a soldering iron. I'm an EE, and I have access to SMD soldering equipment at work (even though everything on this floppy drive is DIP components and lots of spacing.

Anyhow, after surveying my floppy drive, I found another 3-pin header labeled "TP1" (probably doesn't mean anything useful), that contains no jumpers on it. I could try putting a jumper in both positions on it, however.
 
Druid6900 said:
Sorry, reading back on that, you wouldn't have the slightest idea if you hadn't grown up with 5 1/4 inch drives.

MS/MM is another set of jumpers on the board somewhere. If they having staking pins, you're in luck and changing the jumper to the other (MM to MS or vice versa) might fix the problem. If they are hard linked, well, how good are you with a soldering iron?

Regardless, if it is the only drive on an untwisted cable, it has to be set to, in your case, DS0.
Click to expand...
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Normal setting in a PC (with a twist for drive A) is MM; if you _must_ use a cable without the twist it should be set to MS in order for the motor to run when the drive is selected (although those jumper designations are not always standard).

Better to just put in a PC-type twisted cable.

And how about telling us the make & model of the drive?

A 720K disk in a 360K drive???

m
 
I don't happen to have another floppy cable with a card-edge connector on it, so I'm stuck using this one for a while at least.

The floppy drive appears to be generic. The model# is JE1020, serial#9604, made in Taiwan. It is has a black face and can fit in a normal 5.25" CD-bay on a computer.

The floppy disks are also the only 5.25" disks I was able to get ahold of on short notice, and they are 720kb disks (although I should be able to format them as 360kb, shouldn't I?)
 
Update: Putting the jumper in either position on the unlabeled 3 pin header had no observable effect.
 
cfenton said:
I don't happen to have another floppy cable with a card-edge connector on it, so I'm stuck using this one for a while at least.

The floppy drive appears to be generic. The model# is JE1020, serial#9604, made in Taiwan. It is has a black face and can fit in a normal 5.25" CD-bay on a computer.

The floppy disks are also the only 5.25" disks I was able to get ahold of on short notice, and they are 720kb disks (although I should be able to format them as 360kb, shouldn't I?)
Click to expand...
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Well, if they're really the relatively rare 96TPI QD disks ("720K" usually refers to 3.5" DD disks) then you should be OK as long as they're blank; if they've been formatted as 720K you'll probably get an error because DOS will try to read them before it formats them, even with the /u option AFAIK.

But it sounds like your problem is that the motor is not being turned on. A straight cable will only work for drive B; if you access drive A it will select drive 0 and light the LED, but the motor on signal will be on pin 14 (DS2) instead of pin 16. The MM/MS jumper selects whether the motor will be turned on with pin 16 (the normal PC configuration) or when the drive is selected; if you don't have that jumper on your drive you would have to connect pin 10 or 14 to pin 16 somehow (14 & 16 are adjacent) or use a cable with a twist. If you've got any spare cable with an edge-card connector you could remove the connector and crimp it on to the original cable beside the 3.5" connector (after the twist).

Can't say I've ever heard of a JE1020...

m
 
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I'll trade cfenton 2 for one 360k disks for the 720k disks (ie I'll give you 20 360k disks for 10 720k disks). That goes for anyone else on the list. I really need some 96tpi qd disks for my Tandy 2000s.
 
On second thought, they are probably 360kb disks. I'm actually using the disks from a copy of "Mickey's Jigsaw Puzzles", which came with the software on 4 x 5.25" disks or 2 x 720kb disks, and it says it is compatible with IBM PC, XT, AT, and Tandy 1000, 2500 and 3000 series.
 
kb2syd said:
I'll trade cfenton 2 for one 360k disks for the 720k disks (ie I'll give you 20 360k disks for 10 720k disks). That goes for anyone else on the list. I really need some 96tpi qd disks for my Tandy 2000s.
Click to expand...
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You can probably get away with good quality fairly new 360K DD disks; AFAIK unlike the 1.2M HD disks there isn't any basic difference between DD & QD disks, only the QD disks were tested and certified to work under the more rigid demands of a 96 TPI drive. A tiny bad spot would be more likely to cause an error under a narrow 96 or 100TPI head than it would under the wider 48TPI head which could pick up enough flux from beside the bad spot.

Quality control procedures have gotten a little better since the days when QD disks were in use (although some people seem to be having more problems with modern 3.5" disks than older ones).

mike
 
cfenton said:
Anyhow, after surveying my floppy drive, I found another 3-pin header labeled "TP1" (probably doesn't mean anything useful), that contains no jumpers on it. I could try putting a jumper in both positions on it, however.
Click to expand...

That would be Test Point 1 and is usually used in the old analog type drive alignment. Jumpering it probably wouldn't do any good.
 
Grrrr!

Grrrr!

This is getting frustrating! I've tried this 360kb floppy drive w/ a straight cable, a twisted cable, I've tried both cable types with the drive set to all 4 positions, and nothing will work! I even got sharkonwheels to just send me kaypro floppies, but they got sent to the wrong address (and evidently lost, somehow?!)!

Does anyone anywhere close to the NYC area have the ability to write some 360kb 5.25" floppy disks?! I really just wanna see this thing turn on at this point!
 
Hi
It seems like I remember that you need to block one of the signal
lines. I think it was pin 24 ( it has been some time ). I recall putting
a piece of clear tape on that pad of the edge connector in the drive.
This is because the 3.5 inch drives used that line for something else.
I'm just not sure what line it was and it is a major job to pull my test
bench apart to see how it is wired.
Of course the other thing is to check for the terminator R-pack.
If this is missing, nothing will work right.
Dwight
 
Dwight Elvey said:
Hi
It seems like I remember that you need to block one of the signal
lines. I think it was pin 24 ( it has been some time ). I recall putting
a piece of clear tape on that pad of the edge connector in the drive.
This is because the 3.5 inch drives used that line for something else.
I'm just not sure what line it was and it is a major job to pull my test
bench apart to see how it is wired.
Of course the other thing is to check for the terminator R-pack.
If this is missing, nothing will work right.
Dwight
Click to expand...
----------
You're probably talking about pin 34; it's used differently on PC/XTs & ATs and especially on non-PC machines, although many just ignored it. There is a surprising lack of standardization of the floppy drive interface once you get away from PCs, and this drive also sounds pretty unusual.

But if it's the only drive the terminator is indeed important, although not all drives had a removable pack.

And of course the drive itself may also be defective; does it work in another machine?

mike
 
MikeS said:
----------
You're probably talking about pin 34; it's used differently on PC/XTs & ATs and especially on non-PC machines, although many just ignored it. There is a surprising lack of standardization of the floppy drive interface once you get away from PCs, and this drive also sounds pretty unusual.

But if it's the only drive the terminator is indeed important, although not all drives had a removable pack.

And of course the drive itself may also be defective; does it work in another machine?

mike
Click to expand...

Hi Mike
Your right, it was pin 34. I recall it just wouldn't work until I isolated it.
Still, missing terminators is a common problem. Too many can be a problem
as well. Those that don't have removable terminators have a jumper
to disable them.
Dwight
 
Could someone explain the "terminator pack" thing in a bit more detail? I'm really not familiar with 5.25" drive interfacing, but I am fairly handy with electronics if I have the proper info. I will try blocking pin 34 tomorrow and see how it goes!
 
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