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8" and 5.25" Floppy Drive Sales, And Repair

M

MicrocomputerSolutions

Veteran Member
Joined
Jul 30, 2012
Messages
563
I've been involved in the repair and sales of 8" and 5.25" floppy drives since the 1970s.

Contact me if you're having trouble, and I be happy to provide free advice.

If your drive/s need need repair, I'll be happy to repair and align them (for a fee).

And if you need drives, I usually have some in stock, ready for delivery.
 
Some people have inquired as to what brands and sizes of floppy drives I can work on, and stick parts for.

I specialize in 8" floppy drives, but also work extensively on 5.25" mini-floppy disk drives. I can work on any 8" or 5.25" drive that uses the standard 50 conductor (8") or 34 conductor (5.25" drive connectors. The equipment that I use to control the drives while testing and repairing works on the standard interfaces, so I'm sorry but I can't work on drives that use non-standard interfaces like early (Apple II) drives. I do not have the alignment disks or circuit diagrams to work on 3.5" drives either.

My drives of choice are Shugarts, but I also have worked on all the other major brands drives like Mitsubishi: Qume, Tandon, Siemens, NEC, Panasonic, Wang, Pertec, MFE, JVC, and Teac. I have the Factory Service Manuals for these other brands because having the circuit diagrams is necssary to pick out the test points, and to trouble-shoot logic board problems.
 
If you are looking for 8" floppy drive parts, I have Shugart (SA800, SA801, SA850, SA851, SA810, SA860), Mitsubishi (M2896-63), and Qume (DT8, DT842, DT242) drives that I am parting out.

I have working Shugart (SA800, SA801, SA850, SA851) AND Mitsubishi M2896-63) 8" drives in stock for sale that have been aligned and tested that include a 6-Month Warranty.

I can test, repair, and align your 8" floppy drive/s if you need it/them serviced.

Michael
 
Might be a good idea to put a location in your profile. This helps people get a sense of the shipping cost to get the drives to and from you. Does not have to be your exact address, just the state would suffice.
 
Hello Michael,

Since you raise the issue....

I have the disk drive unit (only) from an old IBM DisplayWriter system. This contains two 8" drives. I believe one is a lower density drive, and the other is the higher type.

The unit is clean, and inside all looks clean, not even THAT dusty. I have manuals for the unit, incl Circuit diags and troubleshooting.

This does NOT use the standard connectors mind you, it's a plug/socket like the standard serial connector, but longer.

What might be my chances of ever getting such drives working, say with a CP/M machine? Might a PC be a better bet?

I have some 8" disks, but I don't have a boot disk.

Geoff
 
Sorry about the delay in answering your question, but you are not going to like the answer. The odds of getting those special IBM drives to work as normal/standard 8" drives is slim to none. they don't have any value to someone that uses standard drives. IBM did not even continue with the special drives. Eventually they went to standard drives.

You best bet is to find someone who is using an IBM machine like the one that the drives came from and unload them on that person.

GeoffB17 said:
Hello Michael,

Since you raise the issue....

I have the disk drive unit (only) from an old IBM DisplayWriter system. This contains two 8" drives. I believe one is a lower density drive, and the other is the higher type.

The unit is clean, and inside all looks clean, not even THAT dusty. I have manuals for the unit, incl Circuit diags and troubleshooting.

This does NOT use the standard connectors mind you, it's a plug/socket like the standard serial connector, but longer.

What might be my chances of ever getting such drives working, say with a CP/M machine? Might a PC be a better bet?

I have some 8" disks, but I don't have a boot disk.

Geoff
Click to expand...
 
Is there anyone out there that can repair 8" Flexible Disk Drives from Magnetic Peripherals? The "Equip. Ident. N." is BR8A8-A and the "Part Number" is 77618023 (but I think this can vary).
 
Hello, I’ve been trying to get Siemens FDD-100-C/D/E drives running again and I’m running into two problems: (1) the protect/write-inhibit logic or sensor seems bad on 2 out of 3 drives tested. From the Siemens manual I can find the trace I need to cut to fix that problem. (2) On all of these old drives, the head refuses to seek/return to track zero. I am able (with the power off) to manually turn the screw to put the drive in the track zero position and when I do that, the drives are able to read and boot from diskettes. I’m assuming there is something wrong with the track zero logic and/or sensor but lack the know-how to trace the problem. If the issue is the head motor, I don’t know where to find a replacements. Would appreciate any help with this!! Thanks, Tom
 
lowrybt said:
Hello, I’ve been trying to get Siemens FDD-100-C/D/E drives running again and I’m running into two problems: (1) the protect/write-inhibit logic or sensor seems bad on 2 out of 3 drives tested. From the Siemens manual I can find the trace I need to cut to fix that problem. (2) On all of these old drives, the head refuses to seek/return to track zero. I am able (with the power off) to manually turn the screw to put the drive in the track zero position and when I do that, the drives are able to read and boot from diskettes. I’m assuming there is something wrong with the track zero logic and/or sensor but lack the know-how to trace the problem. If the issue is the head motor, I don’t know where to find a replacements. Would appreciate any help with this!! Thanks, Tom
Click to expand...

If the drives will read the boot disk after you manually set the head to Track Zero, I would say your problem is that the Track Zero Sensor needs to be adjusted. If the Track Zero Sensor was not working at all, manually repositioning the head assembly would not help.

The way that Track Zero works on most 8" drives, is a mechanical flag mounted to the head assembly interrupts a light sensor mounted on the chassis towards the rear of the floppy disk, two-four motor steps before the heads reach Track Zero on the floppy disk. The drive's logic keeps track of when the Track Zero sensor indicates the Track Zero Sensor flags, and knows that the next time the stepper motor located to Zero Winding, the heads are located at Track Zero.

When we use an alignment tester, or oscilloscope and a alignment disk to find Track Zero. We move the drive's head stepper motor to the Zero Winding, then mechanically adjust the head assembly so we can read the Track Zero Signal on the alignment disk.

It sounds to me like the Track Zero Sensors on your drives are working, but the Track Zero Flags on the head assemblies are mis-adjusted, so the flags are tripping the Track Zero sensor too early or too late.

IF the drives were sent to me for service, I would start by set the head alignment, then set the Index alignment, and then reset the Track Zero Sensor alignment., before testing the drive on a computer for proper operation. You must set the head alignment first, so you can accurately set the Track Zero Sensor flag to the write track so it will flag before the head reaches Track Zero.
 
Hello, I inherited a trs 80 model 2 and I cannot get past a boot dc error. I know the disks are fine so I would like to send the shugart 801 to you for testing and repair. Visually it’s looks to be in good condition but it has been sitting for decades Are you interested
 
Repair of 8” Siemens Drive

Repair of 8” Siemens Drive

Hello,

If you are still servicing drives, could I send you the unit with issues described below for repair? What is the procedure/cost.... Thanks, Tom

MicrocomputerSolutions said:
If the drives will read the boot disk after you manually set the head to Track Zero, I would say your problem is that the Track Zero Sensor needs to be adjusted. If the Track Zero Sensor was not working at all, manually repositioning the head assembly would not help.

The way that Track Zero works on most 8" drives, is a mechanical flag mounted to the head assembly interrupts a light sensor mounted on the chassis towards the rear of the floppy disk, two-four motor steps before the heads reach Track Zero on the floppy disk. The drive's logic keeps track of when the Track Zero sensor indicates the Track Zero Sensor flags, and knows that the next time the stepper motor located to Zero Winding, the heads are located at Track Zero.

When we use an alignment tester, or oscilloscope and a alignment disk to find Track Zero. We move the drive's head stepper motor to the Zero Winding, then mechanically adjust the head assembly so we can read the Track Zero Signal on the alignment disk.

It sounds to me like the Track Zero Sensors on your drives are working, but the Track Zero Flags on the head assemblies are mis-adjusted, so the flags are tripping the Track Zero sensor too early or too late.

IF the drives were sent to me for service, I would start by set the head alignment, then set the Index alignment, and then reset the Track Zero Sensor alignment., before testing the drive on a computer for proper operation. You must set the head alignment first, so you can accurately set the Track Zero Sensor flag to the write track so it will flag before the head reaches Track Zero.
Click to expand...
 
lutiana said:
Might be a good idea to put a location in your profile. This helps people get a sense of the shipping cost to get the drives to and from you. Does not have to be your exact address, just the state would suffice.
Click to expand...
Michael Louie (Microcomputer Solutions) was based in Rialto, CA

GeoffB17 said:
I have the disk drive unit (only) from an old IBM DisplayWriter system. This contains two 8" drives. I believe one is a lower density drive, and the other is the higher type.
This does NOT use the standard connectors mind you, it's a plug/socket like the standard serial connector, but longer.
What might be my chances of ever getting such drives working, say with a CP/M machine? Might a PC be a better bet?
Click to expand...
Geoff -
Very familiar with the IBM DisplayWriter and the IBM 6360 Dual 8” Floppy Drive Cabinet (often called “The Toaster”).
About ten years ago, I looked at the DIY work required to interface the 6360 to S-100 systems or 1983 IBM-PC/XT.
I elected not to pursue, after reading Michael’s earlier postings and potential scarcity ($$) of future repair parts.

Some Quick Facts:
* IBM Displaywriter System, released in June 1980, used an Intel 8086 processor.
Supposedly, in early 1980s, a version of CP/M was ported ... but unlikely officially released.
https://en.m.wikipedia.org/wiki/IBM_Displaywriter_System
* The 6360 System used three different types of 8” floppy drives, defined by “IBM Type”
Type 1 (SSSD), Type 2 (DSDD), and Type 2D (DSDD)
During this time period, IBM used 8” floppy drives on their System 34/36/38 computer system
as well as older IBM SNA mainframe terminal controllers (3274)
https://en.m.wikipedia.org/wiki/List_of_floppy_disk_formats#IBM_8-inch_formats
===
Michael provided good advice about IBM’s early drives, due to their proprietary parts.
There are some small shops and former IBM Techs that work on these drives (IBM dropped support in late 1990s),
for support of older IBM System 34/36 owners.

One DISADVANTAGE is that the Type 1 and Type 2 floppy drives are BELT DRIVEN (Not Direct Drive),
hence speed accuracy (slipping, worn belts) is less precise.

While the IBM 6360 could be adapted for S-100 computer usage ... it REQUIRES KNOWLEDGE and GOOD DIY Skills.
For example, DC Voltage sources (24 Volts) and Custom cable building from the 8” Drive (inside 6360) to your S-100 controller card. The original IBM Displaywriter had proprietary floppy controller in its base (below monitor) with proprietary cabling.

gb
 
Geoff -

The IBM 3740 was released in 1973 and featured the first usage 8” floppy drives/media (first standard). IBM 3740 format 8-inch SSSD disk 241Kb (77 tracks, one head, 26 each 128 byte sectors per track with a skew of six).
This was the disk format used for exchange between all the CPM-80 8-inch systems and software providers.
https://en.m.wikipedia.org/wiki/IBM_3740

This Wikipedia page should be helpful.
Many of the IBM Displywriters used Single Sided drives (Type 1, 33FD),
only the later production models used Double-sided drives.
https://en.m.wikipedia.org/wiki/List_of_floppy_disk_formats

Bill Beech, NJ7P has a nice write-up on Floppy Drive Formets, Standards, and Geometry
http://www.nj7p.org/Computers/Disk Subsystems/floppies.html
===
Here are two (2) “Widgets” that may help with your IBM 8” Floppy Drive project.

One handles 50-pin Data/Control, the other addresses 24V requirement of 8” floppy drives.

FDADAP Board
http://www.dbit.com/fdadap.html
The D Bit FDADAP board is a small adapter which adapts 8" floppy disk drives (Shugart SA800 style bus) to work with the PC 3.5"/5.25" floppy disk cable pinout. It has 34- and 50-pin connectors which can be connected to the PC floppy controller and the 8" disk drive using simple straight-through ribbon cables (not included), and a 3.5" style power connector for the on-board microcontroller.

FDDC Power Converter
http://www.dbit.com/fddc.html
The D Bit FDDC is a DC-DC converter which boosts/negates the voltages from a PC power supply to those needed by most 8" floppy drives. It can attach to an IDE power connector on a PC's power supply that has sufficient capacity to power both the PC and an 8" drive, or it can work stand-alone from its own dedicated ATX power supply (it has circuitry to drive the ATX "power-on" signal using a momentary pushbutton as input). The outputs are supplied via a 6-pin AMP Mate-N-Lok connector using the standard Shugart pinout.


D Bit
139 Stafford Road
Monson, MA 01057
e-mail Inquires: info@dbit.com
Voice: +1 (413) 267-4600
 
Hello Microcomputer Solutions,

I sent a private message but read closer and you don't work on 3.5" drives. Still I have a couple 5.25" Teacs and a 5.25" Toshiba that need some some TLC.

If you know anyone that does Sony & NEC 3.5" drives that would be wonderful.

Thanks!
 
I have a Fujitsu M2551A from a computer I've had since the late 80s, so I've been the only owner. I've been trying to read some of my old 5.25" floppies and the drive can read the folder structure just fine, and even copy a small file or two after giving a sector not found error. I have tried nearly 20 disks and all exhibit the same issue, which leads me to believe it is the drive and not the disks. I can run imagedisk and the alignment test, and it sees data on all 40 tracks as i move through them. I can take a blank floppy and format it, and if I copy files to the newly formatted disk I see some of the same errors. Running scandisk almost always sees an issue with only the media descriptor and file allocation table and says it is fixed, but it never finds an issue with the directory or file structure. Surface scan also comes back okay. Scandisk results in saying a FAT media byte was replaced and the copy of the FAT was replaced. It does not fix the actual errors though, running scandisk again on the same disk usually says the same thing about the FAT media byte being fixed. Any help would be greatly appreciated.
 
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