Apple Elite Series Computer Drive User Manual


 
ELITE SERIES USER MANUAL APPEN. C - CP/M NOTES
C.3. Seek Configuration Table
The seek table is what informs the 6502 RWTS
disk drivers of the head movement character-
istics of each drive. The table contains 16
entries, one for each CP/M logical drive. The
SELDSK vector will return the [IY] register
pointing to drive [C]’s entry within the table.
The base of the table is drive A: ‘s entry, and
each entry is a single byte.
Bits 7 (MSB) through 1 determine the seek speed
used when seeking the drive from cylinder to
cylinder. Bit 0 (LSB) is the single phase per
cylinder flag hit.
0000 000X = Spiral Cam Seek Rate
0000 001X = Lead Screw Seek Rate
0000 0l0X = Band Pulley Seek Rate
XXXX XXX0 = Two Phases per Cylinder
XXYX XXX1 = One Phase per Cylinder
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