Floppies: controllers, cabinets, disks, docs & hints

This Web page last updated dated Nov 11 2024

This page is about floppy diskettes. There is a lot of information about floppy drives and S-100 on this page, including Web links. (There was also "classic" hard drive information here: that info is now on another Web page.) To contact me, or for ordering information follow this link. To return to my S-100 list click here.

On This Web page:

My other Web pages on floppy drives:
Hard drive information that used to be here

Here is how to order or to contact me


Floppy diskettes for sale

Conditions and categories of diskettes

Please review this information before you buy or use diskettes. The more you know the better decisions you will make. We also have a technical page on floppy diskettes and drives.

For all disks, pease specify SINGLE or DOUBLE SIDED (important) and SINGLE or DOUBLE DENSITY (less critical, I'll explain). If in doubt, describe or send an image of the label side of one of your diskettes. Used diskette sets will be matched by brand as stocks allow. Brands include IBM, 3M, Verbatum, Dysan and others. We have some "no brand" unlabled disks also.

Write protected diskettes: 8-inch diskettes may have a "write protect notch" on the front edge of the envelope. Here's a photo of that notch. If that notch is exposed as shown in the photo - your diskette cannot be written or formatted. You must put a small lable or dark tape over it. Small reflective labels are shown in the photo. Meanwhile, 5.25" diskettes have a notch on the SIDE, and it must be OPEN to permit write, and you must COVER it to "write protect" the diskette. A customer returned some 8-inch disks because he did not know about "write protect".

Used stock comes in various descriptions and is as described, it's not junk: "used a few times" means these were backup disks only used once or twice.

Diskettes are specified by "density" of recording. "single density" and "double density" use the SAME diskette media (coating) and only require reformatting by you, on your computer. "high density" is a different media (coating); we don't recommend using high-density diskettes as single or double density; you cannot reliably use double-density diskettes for high-density use.

About diskette condition: These disks are decades old. Due to age, we are obliged to open sealed unused boxes, inspect, and possibly test EACH 8-inch diskette sold. We make efforts as described with our prices, but these disketes are sold AS IS. Even on the shelf and sealed or boxed, these decades-old diskettes can become damaged, their surfaces become brittle or moldy. If you insist on an originally-sealed box, you assume ALL RISKS OF USE. LIkewise, we cannot guarantee disks are error free, free from mold, etc. We try, and customers have not complained.

Please review the information above before you buy or use diskettes. The more you know the better decisions you will make. Conversely, don't punish me with no sales, for telling you what I know.

I need your FULL SHIPPING ADDRESS for your order, payment by check or money order or "cash" - US paper currency. Follow this ordering link for more ordering info and my email address. Orders outside the USA will cost more, I'll provide a quoted cost.

8-inch diskettes

Note: review the information above before ordering.

If you want ONE or TWO 8-inch diskettes, follow this link.

multiple 8-inch diskettes for display only.

If you have specific requests about type, condition, look, etc. etc - it will raise the price. BE SPECIFIC. Otherwise you can buy as described below. Shipping weight per box, 1.5 lb + 1.0 lbs per ten

8-inch diskettes, unused old stock , brand name, in boxes of ten: if sealed boxes will be opened and inspected, see the notes above.

8-inch diskettes lightly used
NOTE: for used disks below, we'll try to provide them all of one brand per set of ten. Give us a few choices of brand if you have a preference.

5.25 inch diskettes:

Note: review the general information above before ordering.

5.25" soft sectored: I have these but they are not uncommon if you search.
5.25" hard sectored:
-- 16 sectors double sided double density (DSDD), new old stock: contact me, not cheap
-- 10 sectors: used only, limited supply, ask.
-- if you have HARD SECTORED disks to sell, let me know.

3.5 inch diskettes:

Note: review the general information above before ordering. As these 3.5" diskettes are still readily found, we don't work hard to provide them. I have some available but go elsewhere for quantity and cheapest price.

3.5" 800K (720K) 3.5" double sided DOUBLE density (not high density). Great for older Mac/Apple equipment, some old non-Apple computers and PC's. Can also use as 400K (360k) (single sided) diskettes. Don't use 1.44M diskettes for 400K/800K/720K format, they won't be reliable years from now.

1.4M 3.5" diskettes - widely available elsewhere.

Diskette cases

Tough plastic cases for 8-inch diskettes, slightly larger than a box of ten 8-inch diskettes. Will hold several diskettes loosely, maybe 15 tightly packed with their envelopes. Various styles and colors, can be stacked or shelved vertically like books. Some styles will fold open and sit on your desk at a convenient angle for easy access. Many available at $15 each plus shipping. A typical way diskettes fail in long storage is due to mold: these boxes provide some moisture protection as well as some physical protection.

Floppy disk drive cleaning diskettes

We have some floppy disk drive cleaning diskettes. Check my Apple Macintosh parts Web page for for cleaning diskettes. Other links will describe how disk drive heads and diskettes get dirty.

CP/M and S-100 floppy disk controllers

If you "want CP/M to run on my S-100 system", please read my Frequent Questions page and my "how to run CP/M" Pagefor answers to that question. If you want docs for YOUR S-100 controller, check my lists of card manufacturers to see if I have the manual for your card. I have a few floppy controller cards for sale but in general I'd rather you ask for a SPECIFIC manufacturer and brand of card rather than "just any". However I do have one brand and model available for general interests. Check my SD Systems Versafloppy II page for the status of S-100 Versafloppy II controller cards and software in my stock.

I have docs, with source code, for many S-100 floppy disk controllers. If you are debugging or repairing a floppy disk controller that is NOT S-100, you may find one of these manuals useful. they are listed by manufacturer and model; start from my S-100 home page to search the lists of manuals. Also, check my list of S-100 Web pointers for sites which also have docs for controllers, or FDC chips such as the Western Digital WD1771, 1773, 1793, and so on. The same considerations apply to older hard disk controllers of course.

Buying floppy drives

Ordering floppy drives

At this time (2003), I have SOME 8-inch floppy drives for sale, tested and working; I prefer to sell replacments by manufacturer and model number . Drive cabinets are priced as below and may be available, ask for availability. At the moment I'm busy with support efforts, including a manuals service and my Mac business, so availability of tested drives and cabinets is limited. This may change if customer interest dictates, so I appreciate encouragments.

You are welcome to request specific drives, by name and model number; or request specific needs for 8-inch drives or related items. Any working drive sold is tested for read, write, seek but not tested or adjusted for alignment. We cannot guarantee that all diskettes can be read by drives we sell, due to possible misalignment, wear or damage to those diskettes; and of course any limitations of your software or hardware when used with these drives. Supplies are obviously limited. We may offer a trade-in value on selected 8-inch drives in reasonable condition: ask and describe your drives. Shipping costs are based on packed weight, varying from 10 to 30 lbs for one drive, the latter for full-height 8-inch drives. Documentation for drives is at extra cost, see below. Cabinets and power supplies for drives are described below.

Floppy drive power requirements

Drives which are 5.25 inch, 3.5 inch, or 3 inch use +5 volts and (for the 5.25 inch drives) +12 volts. 8-inch drives use +5V, +24V, and in many cases 110VAC 60Hz for the spindle motors.

You should confirm your power supply connectors will mate with whatever drive you get. There are a few configurations of power connectors: all 8" drives use a 50-pin edge connector for data and control. Some drive motors run off 110AC, many 8-inch drives (including the half-heights) use 24V DC for the stepper and spindle and +5 volts to power their logic. Some early drives (Shugart 800) require -5 volts, or a source of negative several volts, to power the read/write circuits. (Shugarts have a jumper to include or short out a -5 volt regulator.). 5.25 inch drive and 3.5 inch drives use +12 volts and +5 volts, some 3.5 inch drives only need +5 volts.

Also, watch for drive model numbers and model variations. For instance, the Shugart 800 vs the 801 is only a matter of some jumper changes. But, there are later models of the 800/801 with entirely different circuitry. If you want from me a "matching" drive down to the chips and jumpers, or a manual for exactly that model, make a photocopy or photo of the drive's circuit board and send it with your order and keep it for reference.



Floppy Drive Cabinets

Various 8-inch floppy drive cabinets are available, ask for details. Shipping extra, weight and size is considerable, espeically with power supplies. These are almost always non-switching supplies. Size about 19 inches wide, several inches high, various depths. With the power supply in the back, these can be 24 inches deep. Most are intended for "full height" drives.

For purchase, please note your location by city/state/zip when inquiring for shipping estimates. Not shipped outside the USA - are you kidding? If you are interested in empty cabinets, PLEASE note what kind of power connector your drives have: there are several varieties. Supply limited, cables also limited. Prices subject to change.

Here's a stack of some 8-inch cabinets
a single 8-inch cabinet
another 8-inch cabinet

in late 2022: Ontel 8-inch drive cabinet, 11 X 11 X 20 inches (full height vertical), no faceplate
both switching (24V?) and open-frame (5V 12V?) power supplies.

A rather sleek drive cabinet was the Heath/Zenith Z-207-41 tabletop 8" drive cabinet. A tan cabinet on rubber feet, with power supply and fan, power switch on front. I have a few of these left, I use them regularly, so I'm not likely to sell one - it's a good example. Shipping weight is 40 lbs for cabinet and power supply, with two drives it typically weighs 55 lbs. A 30-page manual is available, ask for a price for a copy.



floppy and hard Drive Documentation

The drive manuals listed below have a variety of information. Typically the older drive manuals (8-inch and 5.25 inch drives) have detail specifications, a list of jumper (option) settings, a description of circuit operation, a list of signals on the drive connector, and often schematics. Later manuals have less information. A clue is the number of pages listed (we charge by the page, and of course any info in the title. You can ask us if you are in doubt, but we generally don't provide an entire index or table of contents upon request.

All documentation photocopied at a per-page fee plus postage and handling. I will quote a price when you order, check my ordering information . Ask for manuals for your specific drive, by manufacturer and model number. If you have a manual I don't, I'd be interested in a trade or purchase of copies. If you need a manual for a drive not listed below, contact me so I can get look for it!

Often I get requests for "just the jumper information". It turns out the jumper info typically is several pages depending on the manual, not just one. And you may or may not need more info from the manual, either to set the jumpers or to maintain or repair the drive, or in some cases the pinouts of the drive connector. But, assuming the jumper info is six pages or less, I'll charge $2 to pull the manual and copy those pages, plus postage and handling to send those pages in a business letter type envelope at several ounces weight by air mail. (Remind me of this policy if you choose it.)

8-inch floppy drive manuals

Optotronics technology, DCU - disk control unit (AC drive motor control), 12 pgs Calcomp 140 OEM Reference manual, 40 pgs, no schematics or parts
Calcomp 142M Tech manual, 60 pgs, parts, schematic and rework notes
California Computer Products, CalDisk 142M Tech manual, 60 pgs, parts, schematic and rework notes
California Computer Products, CalDisk 143M (2-sided) Tech manual, 50 pgs, parts, no schematics
{Calcomp bought CalDisk so manuals may be identical. The 142 use different
read data decoder boards for FM or MFM format - if you use that option.
Control Data spec sheets, 9406-4 4 pgs, color photos
Control Data brochure, 9406 9404 and 9408 9409. 4 pgs color
Control Data (CDC) (MPI) BR803, BR8A3, BR8A2, BR8A5, BR8A6 models, 76 pgs. Includes adaption to Shugart-like signals.
Dysan 360/2A 8-inch alignment disk instructions, 1978, 8 pages
Dysan Maxi 48 TPI Diagnositc diskette manual, for 808-100, 808-200, 808-300, 808-400; 4 pgs
iCOM - see
this Web page
IMI 5007 disk drive, Cromemco HD5 manual #023-6028, January 1982, 104pp.
Innovex 200M Floppy Disk Drive Maintenance manual, Oct 1975. 68 pgs
Magnetic Peripherals Inc (CDC) (MPI) BR803, BR8A3, BR8A2, BR8A5 models, 76 pgs. Includes adaption to Shugart-like signals. 76 pgs
Mitsubishi M2894-63 Standard Specifications, 46 pgs
Mitsubishi M2896-63 manual by Mitsubishi, standard specifications 68 pgs, schematics
...this version has all small IC's oriented PARALLEL to 50-pin edge connector
Mitsubishi M2896-63 manual sold by Heath/Zenith, 60 pages, schematics
...this version has IC's between power and head connectors PERPENDICULAR to 50-pin edge connector
Matsushita JA-751A specification, 36 pgs
NEC FD1165 maintenance manual, copy, 100 pgs
NEC FD-1165 Product Description manual, copy, 44 pgs
PerSci drives: Cromemco
-- PerSci 299B disk drive technical manual, Cromemco #023-6000, April 1981, 50 pp.
-- PerSci 277 disk drive allignment procedure, Cromemco #023-6008, March 1980, 15 pp.
-- PerSci model 277 diskette drive product spec, Cromemco #023-0057, 25 pp.
-- PerSci 277 disk drive instruction manual (parts list and schematics), Cromemco #023-0016, May 1980, 50 pp.
PerSci drives: IMSAI
-- Persci model 70, 270, 277, 1070 documents - See my IMSAI Web page
-- model 277 dual Spec sheet, 2 pages, 2-color 1977
-- model 70 Spec sheet, 2 pages, 2-color 1977
-- model 270 dual Spec sheet, 2 pages, 2-color 1977
-- 1070 Intelligent Diskettte Drive Controller (summary), 8 pages text
Persci:
-- Product Specifications Model 277 July 1978 24 pages
-- PCB assemblies, logic schematic diagrams, 1979, models 270 272 277
Pertec FD400 FD410 FD500 FD510 etc.:
...see my MITS/Altair Web page for other Pertec docs
Qume DataTrak 8 (full height) (DT8) Product Specifications, Apr 1979, 13 pgs
Qume DataTrak 8 maintenance manual, Jan 1980, half sized, 80 pgs
Qume DataTrak 8 maintenance manual, Jan 1980, full sized, first 40 pages plus HALF of last 40 pgs
QumeTrak 842 drive - same as Qume DataTrak 8 or DT8 as above
QumeTrak 842 maintenance manual, Dec 1981, 96 pgs (from copy)
Qume 242 (half height) product manual, 27 pages (from copy)
Qume 242 maintenance manual, schematics 92 pgs (from copy)
Remex tech manual, RFD4000-A, RFD4001-A RFD2000-A, RFD2001-A, 1979. over 125 pages
Siemens (Singer, World Disk Drives) FDD100-8 manual, 90 pgs
Siemens (Singer, World Disk Drives) FDD200-8 manuals:
-- Volume 2 Tech Manual, parts and procedures. 36 pages
-- Volume 1 Tech manual, operation, theory, installation, 94 pages
-- no schematics, different from FDD-220 circuit board

Shugart SA800, SA801 manuals below from 1977: 25100-25017 models (small IC chips)
Shugart SA800 Double Density Design Guide - App. Bulletin, 1977. 33 pgs.
Shugart SA800 SA801 OEM manual, 42 pgs (jumper and use information)
Shugart SA800 SA801 maintenance manual, 30 pgs (schematics, testing advice)
Shugart SA800 SA801 illustrated parts catalog, 16 pgs (parts diagrams& lists)
Shugart SA800 SA801 Theory of Operation,31 pgs (parts diagrams& lists)
Shugart Spare parts price list, see below

Shugart SA800, SA801 manuals below for PC board #25136 (all small IC chips) and 25229 (w/ large LSI chip)
--- also numbers 2510X, 2517X, 25229

Shugart SA800 SA801 Service manual, 1981.Theory, maintenance, 100 pgs
Shugart Spare parts price list, see below

Other Shugart manuals:
Shugart SA850, SA851 service and maint. manual, copy, 100 pgs
Shugart application note, "replacing an SA850/851 with an 860", 8 pgs
Shugart Spare parts price list, 1980 and 1981. For SA 800, 801, 810, 850, 860? drives. 30 pgs.
Shugart SA810, SA860 OEM manual, 54 pgs
Shugart SA810, SA860 OEM and service manual, 112 pgs
Shugart SA809 drive exercisor manual, from copy, 8 pgs
Shugart SA900, 901, 902 maintenance manual. schematics. 74 pgs
Shugart SA900, SA901 OEM manual, 38 pgs

Synetic FDS-2 - see this Web page
Tandon TM848-1, TM848-2 Product Specification, 16 pgs
Tandon TM848(-1,-2) 8" drive technical manual, Rev B, C, D, Dec 1982, circuit board 210060 or 210094, 96 pp.
- above same as Cromemco #023-6040 service manual
Tandon TM848-1E, -2E OEM, oper., service manual, 1983, circuit board 210742-000 or 210772 or 210771, 93 pgs
Wangco 82 floppy drive oper. & maint.manaual, Cromemco #023-0058, 1981, 50 pp.
Y-E Data YD-174 Two-Sided Diskette Drive, schematics, 10 pgs
Y-E Data YD-180 8-inch drive manual, from copy, 30 pgs

5.25 inch floppy drive manuals

Canon photos of MDD200, MDD400 series, 2 pgs each
Canon MDD-210, -220 tech guide, 40 pgs
Canon MDD-210, -220 product brief, 16 pgs
Control Data spec sheets, 9415 2 pgs, 9415-80 2 pgs, 9406-5 4 pgs,
Control Data brochure, 9406 9404 and 9408 9409. 4 pgs color
Control Data (CDC, MPI) 9429 Hardware Maintenance manual, 64 pgs
Control Data (CDC, MPI) product specification for 9429, 77715860, 46 pgs
Control Data (CDC, MPI), Application note, "PLO and Write Precompensation for 5.25 inch FDD's", 77653447, 40 pgs
Control Data, Application note, "5.25 inch FDD Format considerations and controller compatibilities", 7589469, 45 pgs
Dysan 282 alignment disk instructions, 6 pgs
Dysan Mini 48 TPI Diagnositc diskette manual, for 508-100, 508-200, 508-300, 508-400; 4 pgs
Dysan Mini 96 TPI Diagnositc diskette manual, for 506-100, 506-200, 506-300, 506-400; 4 pgs
Epson SD0540 series specification, schematics, 34 pgs (copy)
Magnetic Peripherals Inc (CDC) 9429 Hardware Maint. Manual, 64 pgs
Magnetic Peripherals Inc (CDC) product specification for 9429, 77715860, 46 pgs

MPI (Micro Peripherals Inc) Model 51/52 product manual rev 3
MPI (Micro Peripherals Inc) Model 51/52 product manual addendum to above
MPI (Micro Peripherals INc) MOdel 91/92, schematic only
Micropolis 5.25-inch drives:
see this documentfor more info and manuals.
Micropolis Floppy Disk Subsystems, binder, Maintenance Manual 1084-02, rev 1 1979
   drive number-pairs below are master drive (slave drive)
   1057 (1037); dual drive 35 track 48 TPI 143KB per drive w/AC supply
   1053 (1033) Mod II; dual drive 77 track 100 TPI 315KB per drive w/AC supply
   1041 (1021) Mod I; single drive 35 track 48 TPI 143KB no AC power supply
   1041 (1021) Mod II; single drive 77 track 100 TPI 315KB no AC power supply
   1042 (1022) Mod I; single drive 35 track 48 TPI  143KB w/AC supply
   1043 (1023) Mod II; single drive 77 track 100 TPI 315KB  w/ AC supply
   100085, 100086 & 100087, S-100 floppy controller 1071 "B" model 4/1977)
   100070, 100071, 10072, floppy drive single "A" card (7/1977)
   100163, 100164, floppy drive single "B" card (5/1978)
   100059, 100060, 100061 floppy drive dual "A" card (12/1977)

Mitsubishi MF501A-3 tech manual, half height drive, 23 pgs
Mitsubishi MF501A-3 maintenance manual, half height drive, 11 pgs
Mitsubishi MF501A-301U illust. parts list, half height drive, 9 pgs
Mitsubishi MF501A-347UA manuals in Tandy 3000 Tech manual
Mitsubishi M4851 OEM manual, half height drive, 65 pgs
Mitsubishi M4851 manuals in Tandy 3000 Tech manual
Mitsubishi M4853 maint. manual, 35 pgs
Mitsubishi M4853 parts list, schematics, 28 pgs
Mitsubishi M4853-1 maint. manual, 18 pgs
Mitsubishi M4853 parts list, schematics, 22 pgs
Mitsubishi M4853 and M4853-1 differences, 8 pgs

Mitsubishi M4854-347 manual, half size (Tandy 3000) as follows:
----jumpers and schematics, UGD-0262A, 9 pgs;
----standard specifications , UGD-0261A, 50 pgs;
----parts list, 14 pgs Mitsubishi MF504A-347UA manual, half size (Tandy 3000) as follows:
----jumpers and schematics, & component layout, UGD-0328A, 20 pgs;
----maintenance , UGD-0343A, 10 pgs;
----technical , UGD-0344A, 24 pgs;
----standard specifications , UGD-0312B, 46 pgs
----illustrated parts list, UED-0135A, 10 pgs
Mitsumi D509V2 service manual, 70 pgs. The manual contains descriptions of how to diagnose faults, and shows mechanical drawings. There are jumper settings and descriptions of them. The table of contents does not show a schematic was part of the manual.
Newtronics Co. Ltd - see Mitsumi
Pertec FD250 Operating and service manual, 36 pgs - *lost*
...see my MITS/Altair Web page for other Pertec docs
Qume 142 maintenance manual, May 1983, full sized, 100 pgs
Shugart SA455, SA465 service manual, 69 pgs
Shugart SA410, SA460 manual (copy), 100 pgs
Shugart SA455/465 OEM manual, copy. specs, jumpers, only. 25 pgs
Shugart SA400 OEM manual, 50 pgs
Shugart SA400 Service manual, schematics, 77 pgs
Shugart SA400L Service manual, less schematics, 30 pgs
Shugart SA809 drive exercisor manual, from copy, 8 pgs
Siemens FDD-100-5B OEM, has schematic and maintenance, 76 pgs
Teac FD-54B specifications, 30 pgs
Teac FD-54 maintenance manual, 72 pgs
Teac FD-55GFV-17 specification, 44 pgs half sized (copy)
Teac FD-55GFR specifications, jumper and mechanical info, no schematics. 21 pages (copy)
Tandon (TM100) 5-1/4" floppy drive manual (Vector computers) 104 pgs
--- TM100-3, TM100-4 TM100-3M, TM100-4M w/schematics & parts, troubleshooting, more.
--- (see Vector Graphics manuals for more info
Tandon TM100 Tech, 100 pgs - ????
Tandon TM100-1, TM100-2 Product Spec & Users manual, 26 pgs, no schematics (copy)
Tandon TM101-4, TM102-2 Product Spec & Users manual, 27 pgs, no schematics (copy)
Tandon TM50-1 TM50-2 Operating and Service Manual, 100 pgs (copy)
-- detailed theory, signals, jumpers, maintenance, schematics.
Tandon TM100 Operating and Service Manual, 24 pgs half sized no schematics (copy)
-- alignment, signal, connector and jumper info.
tandon TM100-2 Product Specification, signals & jumpers but no schematics 16 pgs (copy)
tandon Product Specification, TM-100-1, -2, -3, -3M, -4, -4M. no schematics 15 pgs (copy)

3.0 inch and 3.5 inch floppy drive manuals

Canon photos of MD350, MDD200, MDD400 series, 2 pgs each
Canon MD350S specification, 30 pgs
Epson SMD-280 spec sheet, 2 pgs
Matsushita EME-160 & -180, 15 pgs
Mitsubishi MF355B standard specification, 46 pgs
Mitsumi D359T2 service manual, 64 pgs (copy), schematic
Panasonic EME-150M tech spec (3.0"), 14 pgs
Panasonic EME-150 & -250 OEM manual (3.0"), 20 pgs
Panasonic JU-313, 323, 363 OEM manual, 38 pgs
Sony MP-F73W-00D & -01D tech note, 26 pgs
Sony MPF73W00D, -01D product spec, 26 pgs
Sony MP-F73W-50 info (buy with MP-F73W-00 docs no extra charge)
Sony MPF920, MPF820 - various data sheets, 6 pages

Hard drive, SASI, SCSI, MRM, RLL and related item manuals

This information is now on another Web page.


Windows/Linux floppy disk controllers & software, versus USB microcontrollers

Some people once asked: "I want to read 8-inch diskettes on my PC/Windows/Linux machine. Please sell me a complete system, or tell me where to get one." Often they have no idea how this might be accomplished. Other people want to read CP/M or other non-MS-DOS 5.25" or 3.5" diskettes, or old Mac 400K or 800K 3.5" Mac diskettes, on a Windows or Linux PC. A few people wanted to read really ODD formats - hard sectored, M2FM, and so on. In the modern era - the 2010's, 2020's - people often want to replace floppy drives completely on their vintage computers, and use instead some modern "product" they can download vintage software (files) into. Or use some "universal" bit-level floppy controller to read off some old diskettes. The following discussion compares solutions from the 20th century - consumer-class Western Digital chip-basedvintage floppy controllers and drives on MS-DOS machines, which I'm familiar with; versus choices available in the 2010's and then the 2020's, which use hobby-class personal-project USB based microcontrollers to read floppies, or to replace floppy drives on vintage systems.


In the early 2010's I added then-modern information, How to read and write "old" floppy diskettes on it's own Web page, look there for details. Links below to the old discussion, now link to the new Web page. Up to the 2010's, the choice was either software for PC-based floppy controllers with then-standard FDC chips; or specialized ISA or PCI cards with specialized hardware and software. Vintage (IBM compatible) PC's are still viable solutions even in the 2020's. Specific links to that document are described below, after I reference modern (2020's) solutions.

In the later 2010's to today's mid-2020's, there's a number USB operated microcontroller boards, designed to operate floppy drives, using specialized Windows/Linux/OSX software. Some of them deliver binary patterns - flux changes from the diskette media. Those are decoded by additional software into the original binary disk image, usable on some vintage-computer software emulator. Or the binary image is loaded into a "floppy disk emulator", a device to be connected to a vintage computer to replace a physical floppy drive with some non-diskette storage device. Or the disk image can be read as a flle system (more software) and the files extracted to modern Windows/Linux files. These modern USB-based floppy controllers are outside my scope and experience. I have some notes from the 2010's about some of them on this linked Web page But I have overall impressions and opinions about them as of the 2020's, as follows.

Many of these microcontrollers, their hardware and software, were projects that only lasted for a few years - they come and go; time will tell if some persist. Some are intended for particular vintage system use (for Apple II, for one brand of vintage computers, etc.) and may be hard to use outside of that particular interest. Support and availability of these as products, depend initially on the developers to produce those boards if they choose. Or, many developers provide "the Gerbers", PC board CAD files, so users (or dealers) are obliged to "send off the files to make PC boards", gather parts and construct individually, program the microcontrollers, and obtain software from users or those developers. A few have persisted as hobby projects, offered by individual dealers or groups of users. I simply can't follow all that work or keep up with such projects. They are outside my vintage preservation/restoration interests and my vintage skills. Web search and social-media about vintage computing, will find current and/or popular projects and whatever support they have, to do whatever they do. Here's an opinion I have about such claims.

The particular virtues of vintage-based floppy controllers, is their availability, and the stable body of work already done to support them. Those based on vintage mass-produced PC floppy controllers, are still available as vintage hardware; they can process most vintage diskettes. Only the earliest kinds of floppy disks, are obliged to be decoded (read) by bit-level or flux-level USB microcontroller based devices and software. Pardon me, but in my opinion it's 1) over-kill and 2) confusing to non-experts, to use bit-patttern microcontrollers to read common brand formatted disks; and then find (or not) compatible software to turn those bit-images back into useful files. They are easily read on a 1990's (IBM-compatible) PC computer or a vintage Mac; or with more effort read on the original computer (Apple II, etc.). Then files can be transferred to modern hardware by various means, including serial or FTP file transfer. If someone using a modern disk-reading product, one you are unfamiliar with, claims to be able to "read your disk" (or claims you can do it) - ask them how that will produce the files you need for YOUR specific purposes.

Discussions about non-USB based vintage floppy controllers

floppy drive controllers with conversion, imaging software - Discussion of various PC based floppy controllers is moved, look there for details.

A reference to Sydex, ANADISK and 22DISK was moved to the Web page on How to read and write "old" floppy diskettes

Catweasel floppy controller - The Catweasle discussion is moved look there for details. That ISA or PCI controller was popular through the 1990's until it went out of production. It was an early bit level or flux-level solution.

Software to support foreign diskettes on Windows-based PC's - is moved to another WEb page, look there for details.

Check my "how to CP/M" Web page for more discussion of Dave Dunfield's imagedisk software tools, and various collection of system disk images. Imagedisk or Imagedsk, runs under MS-DOS on PC compatibles using ISA or motherboard-based floppy controllers with Western Digital-compatible floppy controller chips and components.



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