There's nothing special about this Winchester formatter in relation to the Master 512, by the way.
This is my own adaptation of the more familiar "Superform". It contains some modifications and improvements from the Acorn version, including a slightly more accurate (well, according to the information given in the Adaptec ACB4000 manual, at any rate!) physical defect location calculator, and the ability to specify the sector interleave to be used. The sectors-per-track is also variable depending on the interleave, as the Adaptec controller can somehow shove in an additional sector per track if you use interleaving (ie. if the sector skew is anything other than 1).
In addition, the formatted size of any given disc is a couple of hundred sectors larger than under Superform, which keeps back 128 sectors at the end of the disc, and it can also cope with discs which format with more than 128 disc errors (the maximum amount allowed in the format-time defect list by the Adaptec board) by ignoring anything after this number of entries when building the defect list.
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