RANA Systems Elite Controller, User Manual

Page: 319 / 328

ELITE SERIES USER MANUAL APPEN. B - DOS NOTES
the desired track and nothing else.) When a “no
Operation” call is made to the enhanced RWTS,
and the sector number in the RWTS parameter list
is set to $FF, a “formatting error” ($08) will
be returned and the carry flag set. This is a
way for the application program to determine
whether or not an enhanced DOS is currently in
use since a non—enhanced DOS would not care
about the sector number during a “no operation”
call.
The enhanced DOS will return the error condition
without selecting any drives or performing any
seeks. in addition, the [AY] register pair will
be returned pointing to the base address of the
drive configuration table located within the
enhanced DOS.
The configuration table is 28 bytes Long, pro-
viding a one byte entry for each of the 4 drives
per 7 slots of controller cards possible. The
entry at [AY]+$00 is for slot 1 drive 1,
[AY)+$01 is for slot 1 drive 2, [AY]+$1A is for
slot 7 drive 3, and [Ay]+$1B is for slot 7 drive
4.
P a g e B - 4