[ Retro Scan of the Week ] The 3-Inch Compact Floppy Disk
August 6th, 2007 by Benj Edwards
Sure, you’ve probably seen plenty of 3.5″ “micro-floppy” disks. But have you ever seen a 3″ compact floppy? I picked up a stack of these at a thrift store about seven years ago. The ones I found were once used with an Amstrad computer (strange to find in the US), which unfortunately wasn’t accompanying the disks at the shop. Amstrad, the once-prominent British computer manufacturer, used these disks in a few of their computer models (the CPC and PCW, or so I read), and consequently, mainstream usage of 3″ floppies was limited mostly to the UK. Sony’s 3.5″ floppy standard took firm hold in the US because of Apple’s decision to use it in the Macintosh.
I’ve seen an advertisement in an old computer magazine for a 3″ 128k compact floppy drive for the Apple II, one of this format’s first applications. Nintendo fans out there might notice similarities between this disk and Nintendo’s 3″ Famicom Disk System media, but Nintendo’s disks used a proprietary format based on a different standard.
A neat history of the 3″ compact floppy disk can be read here.
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August 6th, 2007 at 1:38 pm
Amstrad also used it in the ZX Spectrum +3, a 128K Spectrum with 3″ floppy disk drive.
August 8th, 2007 at 7:22 pm
Interesting article. I had seen these drives sold my Amdek in magazines roundabouts ’83-’84, ususally in a slick looking dual-drive enclosure, the Amdek Amdisk I:
http://www.backntime.net/Atari%20Computers/8bit/3rd%20Party/Frame8bit3rdparty.html
( top of page )
In ’87 or so I found a place selling single-drive versions of these for the Apple II for cheap ($30?) so I grabbed one. I had a IIe with a single Disk ][ drive, and this unit just plugged into the Disk ][ controlled. The system though it was a standard 143K 5.25″ floppy. I copying the 2nd disk of Ultima IV to one of these 3″ disks so I did not have to do the floppy shuffle. I’ve still got this disk down in my compute room today! I sold the IIe along with that drive 20 years ago, however.
I’ve always thought the 3″ was an interesting excursion in the course of computing history. Thanks for posting.
August 8th, 2007 at 8:07 pm
Thanks for your comment and story, Blake. I too have seen ads for those Apple II-compatible Amdek drives. I think I ran across one recently in an old magazine I have. If I find it again, I’ll scan it and put it up somewhere.
November 21st, 2007 at 12:51 am
I’ve actually got a couple of these lying around actually, but the computer I had with a drive is long gone, it was a laptop as I recall.
August 19th, 2012 at 8:38 am
I found 6 of these drives…5 have dip switches and one has a socketed chip at the edge connector without dip switches. Any information on the setting of these switches for use with Timex/Sinclair would be appreciated.
March 10th, 2015 at 4:44 am
The 3 inchers were actually used by : Amstrad CPC range, Sinclair Spectrum+3 range (Amstrad made ones), Amstrad PCW (“word processor, actually a Z80 CP/M computer), ORIC ATMOS, Tatung Einstein.
Some PCW could include a double-sided variant of the disk drive. Those PCW sold in millions units for small businesses or homes.
Those 3” were expensive but fast and reliable.
And weren’t reserved to UK as Amstrad sold a lot of computers in Europe (France, Spain, Germany with schneider branded Amstrad CPCs, greece) and even Australia. Amstrad CPC being the msot sold 8bit home computer in France, those were quite a common sight here as many CPC6128 users existed (a few still using them… ^_^
You may find more details at cpcwiki.eu