ARPAVAX:C70:info-cpm (09/13/82)
>From UCBVAX.teklabs!azure!laurir@Ucb-C70 Sun Sep 12 18:29:03 1982
To: teklabs!ucbvax!C70.info-cpm at Ucb-C70
Via: Mit-Ai; 12 Sep 82 17:58-EDT
Via: Brl; 12 Sep 82 19:27-EDT
Via: Brl-Bmd; 12 Sep 82 19:49-EDT
This is in response to a correspondent who would like to use the S1,
S2, and CR fields of a CP/M disk directory entry to record a file
date/time stamp.
S2 holds the overflow bits from the extent number. Under CP/M v1,
extent numbers were five-bit entities and are shoe-horned into the
low five bits of the EX byte. With CP/M v2, extent numbers are lengthened,
with bits 5 and up (least significant is bit 0) stored in S2.
The disk directory entry contains only 32 bytes, not 36 bytes as a
File Control Block does. The CR field, the 33'rd byte, isn't stored.
I haven't yet found a purpose for S1. Does anyone know?
-- Andrew Klossner (laurir.tektronix@udel-relay)
(decvax!teklabs!tekmdp!laurir)