Sykes 7100/7200 Programs to Read And Write DEC Format Diskettes
8-872
Author: I. M. Templeton
National Research Council Of Canada
Operating System: OS/8
Source Language: PAL-8

Abstract: The Data on a DEC diskette is written in 3/4 filled,
interleaved sectors. It appears to be impossible to unscramble these via
an OS/8 handler within the timing restrictions of the unbuffered sykes
system, so the present approach has been used. The 'read' program reads
sectors sequentially, two tracks at a time, and deposits the data in the
correct (interleaved) places in a 6400-word buffer (in field 3, but this can
be changed). This buffer is then copied, via a standard OS/8 handler, to
an alternate file-structured device. As written, the program uses the
(already resident) system handler with the unit set to 2, and writes the
copy on a blank diskette, but any appropriate variation of this may be
used. The 'write' program does the opposite, first filling the buffer from
the source device, and then copying that to the DEC diskette in such a
way as to reproduce the correct interleaving while writing sequentially.

Media Price Code: D2, K27
Format: OS/8
Catalog: August 1978