17 Jul
2023
17 Jul
'23
2:33 p.m.
On 7/17/23 11:53, Ethan Dicks via cctalk wrote:
Chuck Dickman's algorithm is in lbn2rx50.c
#define RX50_TRACKS 80
#define RX50_SECTORS 10
int interleave[] = { 0, 2, 4, 6, 8, 1, 3, 5, 7, 9 };
track = lbn/RX50_SECTORS;
track = (track + 1)%RX50_TRACKS;
sector = lbn%RX50_SECTORS;
sector = (interleave[sector] + 2*(track - 1) + RX50_SECTORS)%RX50_SECTORS;
Depends on the application. Files-11 RX50 encoding is a bit stranger,
with Track 79 mapped to physical track 0.
I can pass my algorithm along, if anyone is interested.
On the other hand, DECMate II and Rainbow use sector interleave but not
track skew.
If anything can be said about DEC, they were consistent in their
inconsistency.
--Chuck