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