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Cumana QFS Double Density Disk Filing System

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Cumana QFS top

 Cumana QFS Double DensityDisk Filing System (top)

Cumana QFS bottom

 Cumana QFS Double Density Disk Filing System (bottom) 

Cumana QFS ICs

  Cumana QFS Double Density Disk Filing System ICs

The Cumana QFS Double Density Disk Filing System consists of 7 ICs, including the sideways ROM, and a disc controller daughter which fits into the BBC IC78 socket (Intel 8271). The Cumana QFS Double Density Disk Filing System uses a Fujitsu MB8877A floppy disk formatter/controller.

The Cumana QFS disc filing system is very similar to the Acorn DFS. The QFS command summary is identical to that of the Acorn DFS and so maintains software compatability. But the QFS includes a built-in FORMAT command which can format discs in single or double density. Single density is the same as the Acorn DFS, double density is 18 sectors of 256 bytes (=360K) instead of 10 sectors (=200K).

Here is the Cumana QFS Users Handbook and Fitting Instructions .