Spludlow Retro Software Catalogue - Floppy

BBC Micro • Acorn Archimedes

Floppy disk formats and sizes

Acorn Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 Single 256 10 40 1 100 300 FM 102400 5.25 Single 256 10 80 1 200 300 FM 204800 5.25 Double 256 16 40 1 160 300 MFM 163840 5.25 Double 256 16 80 1 320 300 MFM 327680 5.25 Double 256 16 80 2 640 300 MFM 655360 3.5 Double 256 16 80 2 640 300 MFM 655360 3.5 Double 1024 5 80 2 800 300 MFM 819200 3.5 High 1024 10 80 2 1600 300 MFM 1638400

Agat Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 Double 256 21 80 2 840 300 MFM 860160

Amstrad PCW8512/9512 Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 3 Double 512 9 80 2 720 300 MFM 737280

Amstrad CPC/PCW Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 3 Single 512 9 40 1 180 300 MFM 184320

Apple II Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 Double 256 13 35 1 113.75 300 GCR 116480 5.25 Double 256 16 35 1 140 300 GCR 143360 3.5 Double 512 8-12 80 1 400 394-590 GCR 409600 3.5 Double 512 8-12 80 2 800 394-590 GCR 819200 3.5 High 512 18 80 2 1440 300 MFM 1474560

Apple Lisa Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 Double 512 15-22 46 2 851 218-320 GCR 871424

Apple Lisa 2/Macintosh XL Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 3.5 Double 512 8-12 80 1 400 394-590 GCR 409600

Apple Macintosh Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 3.5 Double 512 8-12 80 2 800 394-590 GCR 819200 3.5 High 512 18 80 2 1440 300 MFM 1474560

Atari 8-bit Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 Single 128 18 40 1 90 288 FM 92160 5.25 Enhanced 128 26 40 1 130 288 MFM 133120 5.25 Double 256 18 40 1 180 288 MFM 184320 5.25 Double 256 18 40 2 360 300 MFM 368640

Atari ST/TT/Falcon Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 3.5 Double 512 9 80 1 360 300 MFM 368640 3.5 Double 512 9 80 2 720 300 MFM 737280 3.5 High 512 18 80 2 1440 300 MFM 1474560

Coleco ADAM Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 Double 512 8 40 1 160 300 MFM 163840

Commodore (8-bit) Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 Double 256 17-21 35 1 170 300 GCR 174080 5.25 Double 256 17-21 35 2 340 300 GCR 348160 5.25 Quad 256 23-29 77 1 521 300 GCR 533504 5.25 Quad 256 23-29 77 2 1042 300 GCR 1067008 3.5 Double 512 10 80 2 800 300 MFM 819200

Commodore Amiga Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 Double 512 11 40 2 440 300 MFM 450560 5.25 Quad 512 11 80 2 880 300 MFM 901120 3.5 Double 512 11 80 2 880 300 MFM 901120 3.5 High 512 19 80 2 1520 300 GCR 1556480 3.5 High 512 22 80 2 1760 150 MFM 1802240

DEC RX50 Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 Double 512 10 80 1 400 300 MFM 409600

IBM PC compatibles Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 8 Single 128 26 77 1 250.25 360 MFM 256256 8 Single 128 26 77 2 500.5 360 MFM 512512 8 Double 1024 8 77 1 616 360 MFM 630784 8 Double 1024 8 77 2 1232 360 MFM 1261568 5.25 Double 512 8 40 1 160 300 MFM 163840 5.25 Double 512 8 40 2 320 300 MFM 327680 5.25 Double 512 9 40 1 180 300 MFM 184320 5.25 Double 512 9 40 2 360 300 MFM 368640 5.25 Quad 512 8 80 1 320 300 MFM 327680 5.25 Quad 512 8 80 2 640 300 MFM 655360 5.25 High 512 15 80 2 1200 360 MFM 1228800 3.5 Double 512 8 80 1 320 300 MFM 327680 3.5 Double 512 9 80 1 360 300 MFM 368640 3.5 Double 512 8 80 2 640 300 MFM 655360 3.5 Double 512 9 80 2 720 300 MFM 737280 3.5 High 512 18 80 2 1440 300 MFM 1474560 3.5 High 512 21 80 2 1680 300 MFM 1720320 3.5 High 512 21 82 2 1720 300 MFM 1761280 3.5 Extended 512 36 80 2 2880 300 MFM 2949120

IBM 3740 Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 8 Single 128 26 73 1 237.25 360 FM 242944

MGT SAM Coupé Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 3.5 Double 512 10 80 2 800 300 MFM 819200

NEC PC98 Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 8 Single 128 26 77 1 250.25 360 FM 256256 8 Double 1024 8 77 2 1232 360 MFM 1261568 5.25 Double 512 8 80 2 640 360 MFM 655360 5.25 Double 512 9 80 2 720 360 MFM 737280 5.25 High 512 15 80 2 1200 360 MFM 1228800 5.25 High 1024 8 77 2 1232 360 MFM 1261568 5.25 High 1024 8 80 2 1280 360 MFM 1310720 3.5 Double 512 8 80 2 640 360 MFM 655360 3.5 Double 512 9 80 2 720 360 MFM 737280 3.5 High 512 15 80 2 1200 360 MFM 1228800 3.5 High 1024 8 77 2 1232 360 MFM 1261568 3.5 High 1024 8 80 2 1280 360 MFM 1310720 3.5 High 512 18 80 2 1440 300 MFM 1474560 3.5 Triple 512 38 240 2 9120 360 MFM 9338880

Osborne 1 Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 Single 256 10 40 1 100 300 FM 102400 5.25 Double 1024 10 40 1 200 300 MFM 204800

Sega SF-7000 Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 3 Single 256 16 40 2 160 ? ? 163840 3 Single 256 16 40 2 160 ? ? 163840

SHARP X68000 Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 High 1024 8 77 2 1232 360 MFM 1261568 3.5 High 1024 8 77 2 1232 360 MFM 1261568

Thomson Format Density Bytes / Sector Sectors / Track Tracks / Side Sides KB RPM Encoding Bytes 5.25 Single 128 16 40 1 80 300 FM 81920 5.25 Double 256 16 40 2 320 300 MFM 327680 3.5 Double 256 16 80 1 320 300 MFM 327680 3.5 Double 256 16 80 2 640 300 MFM 655360

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Floppy disk advice

When using real hardware, you may well want to use real floppy disks. Here’s a few points to note:

·         There are various hardware virtual floppy drives that plug into a real floppy disk controller and you can put in SD / CF cards making it easy to transfer disk images from a PC. You may want to consider using these.

·         Many floppy disks will have bad sectors. I’ve been formatting a load and about only 10% format without any errors.

·         Even disks that don’t format 100% can still be used to put games on, hopefully data won’t be on the bad sectors. Especially for multi game disks, if the games you want to play work.

·         It can be difficult to prepare disks on real vintage systems, consider preparing them on a PC.

·         You use an emulator on a PC to prepare disk images, some emulators have a shared host folder so transferring files is simple.

·         Note some system like the Archimedes filesystem carry additional file meta data, like “file type” so if you extract an archine on a PC this information will be lost. You have to either set it back or perform the archive extracts on the native system.

·         Writing disks from a PC is possible (see below) but most vintage formats will require a disk drive attached to the motherboard the USB types will not work.

 

Setting up an OmiFlop PC

OmniFlop is by far the best piece of software for writing retro disk images to real floppy disks.

http://www.shlock.co.uk/Utils/OmniFlop/OmniFlop.htm

It’s unlikely the PC you are using now has a floppy disk controller on the motherboard so I would recommend obtaining and configuring a PC just for wringing floppies.

·         You need a PC with a floppy disk controller (FDC) on the motherboard.

·         You will need a real floppy disk drive that connects to the mother board.

·         Install Windows 7 32 bit, the CPU in older machines probably will not work with current windows versions due to CPU feature requirements, I tried it, Windows 7 is the latest that works.

·         Use 32 bit install of Windows, there are additional driver installation steps required for OmiFlop, it is possible on 64 bit but not worth the hassle.