View Full Version : IBM PC 5150 floppy issues

April 7th, 2014, 01:41 PM
Hey guys I'm back again and need some more help with my ole 5150.

This time I'm trying to get my 5.25 floppy drive working. My system has 2 of them but I took one out to put in a 720k/1.4mb drive for booting later versions of dos.

I have a decent collection of software on 360k disks and was trying to use some of them in drive B while booting dos 3.3. The issue is it lets me format some of my blank disks but it only lets me format them to ~160000 and shouldn't they be 360000? Also I am not able to read any of my old software but it lets me sometimes read the disks I burnt with the system. I have tested the old disks before in a Pentium 1 system and at the least they were readable with the same floppy drive. Now I try to do dir and then I either get general read error or another floppy disk error and the disks don't read. Since I couldn't get anything to work with that drive I replaced it with the second drive and removed the t-res chip and it gets the same symptoms.

I tried cleaning the drive with a can of air and blowing the dust out and that didn't seem to work, I also used a q-tip on the head and that didn't help either. I'm not really sure whats going on since I used one of the drives from the system to read the disks in windows 95 on the pentium 1 system.

I also tried a different floppy disk controller I have that supports high density drives and it won't let the drives work either. Does anyone have any suggestions? The drives always power on fine and the system always makes attempts to read from them. I get no errors when powering the system on and I have the same configuration from my other posts (NEC V20 10Mhz, Intel 8087 10Mhz fpu, 512MB ram, 1 1.4mb drive, 1 360k tandon drive)

Furthermore I found a website a long time ago about a guy that completely maxed out his 5150 but he found a software way to get the system to read 1.4MB disks. This would be great since some software doesn't fit on the 720k disks and I would like to try running a few things that are 1M. Does anyone have the link to this website or know how to use 1.4MB floppies on a IBM 5150?

Thanks, Oz

April 7th, 2014, 01:52 PM
Have you tried a cleaning diskette with solution? If you haven't done this you need to do it before trying anything else. Dirty head(s) are a major culprit in situations like this.

April 7th, 2014, 02:46 PM
I tried some solution on a q tip and rubbed it on the heads. I haven't been able to justify a glorified empty floppy case with a little pad for $15 when I can get 50 real 5.25 floppies for the same price. Wouldn't the q tip pretty much get similar results?

April 7th, 2014, 02:50 PM
Just +1'ing what Stone has said.

180KB disk formats is what happens when the second drive head has become clogged. It only takes one bad disk to cause the problem - so having a cleaning disk and some isopropyl is a real life saver. Over half of the media I receive (donated or purchased) has stuff growing on the media surface.

At $15 it's a bargain considering the time it'll save you. I've always found them much more effective than manually cleaning the heads.
Of course the drive could be faulty, or it could be a cable issue, but most of the time I've found it's dirty heads.

April 7th, 2014, 03:04 PM
What model of drive is this? A tandon fullheight? Can you visually inspect the heads and see if there is buildup or damage? Also check the wires running from the heads to the logic board, once and a while those can come loose while messing with things.

The way to add a 1.44mb drive to an 8088 system is to either get an 8-bit ISA FDC with a BIOS, or install a more common 16-bit AT FDC in an 8-bit slot and then use the "2M-XBIOS" driver.

April 7th, 2014, 03:07 PM
I haven't been able to justify a glorified empty floppy case with a little pad for $15 when I can get 50 real 5.25 floppies for the same price. I don't get this analogy. If you were to get a thousand floppies for free they wouldn't help in cleaning the drive's heads. And, they'd be rendered completely *useless* until you did clean the heads. What good are disks if you don't have a drive you can use them in? :-)

April 7th, 2014, 03:10 PM
Can you visually inspect the heads and see if there is buildup or damage?You can't see any buildup on the heads. It's not visible -- it causes electromagnetic interference.

April 7th, 2014, 03:16 PM
Lol looks like I'm going to have to be making some purchases on ebay. A new memory board clock battery, a floppy cleaning disk, and some more ram chips.

Yes it is a Tandon full hight and I can not visually see anything wrong. I am going to try the 2M-XBIOS thanks for that I forgot the name and I have my 16 bit floppy controller setup to use it.

April 7th, 2014, 03:59 PM
IMO, anybody who uses old floppy disks, and let's face it, it's 2014 and *all* floppy disks are old by now, NEEDS a disk cleaner for each type of floppy drive. Admittedly, 5" drives (and especially Double Density disks) are far, far worse than 3" drives but even 3" drives get fouled by the disks' oxide coating on occasion, just not nearly as often. I started cleaning floppy drives with these diskettes 25 years ago when I was handling huge amounts of software on a regular basis and have never looked back or regretted having stocked up on this essential cleaning material.

April 18th, 2014, 08:22 AM
Okay my floppy cleaner disk came in the mail today and I ran it a few times through and the drive still doesn't want to work. It seems to be also formatting at only 180k and not 360k no matter what drive I try to use. I have switched between 2 different ones. I am not sure if the floppy controller I use makes a difference or if it has specific jumper settings but I am using a high density 16 bit controller so that was I can eventually read 1.4MB disks when I get a xtide and a HDD.

April 18th, 2014, 09:24 AM
It's possible those Tandon FH drives don't respond properly with that 16-bit controller. Try them with the original PC or XT floppy controller.