From: utzoo!decvax!ucbvax!ARPAVAX:C70:info-cpm Newsgroups: fa.info-cpm Title: Re: the s1, s2, and cr fields in a CP/M disk directory Article-I.D.: ucb.1935 Posted: Sun Sep 12 18:29:16 1982 Received: Tue Sep 14 05:12:07 1982 >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)