Apple 13-0010--001 Computer Drive User Manual


 
ELITE SERIES USER MANUAL CP/M ENHANCEMENTS
For a Disk It drive, STAT will respond with the
following:
A: Drive Characteristics
1024: 128 Byte Record Capacity
128: Kilobyte Drive Capacity
48: 32 Byte Directory Entries
48: Checked Directory Entries
128: Records/ Extent
8: Records/ Block
32: Sectors/ Track
3: Reserved Tracks
The drive capacity in records and kilobytes is
what will primarily interest you. Also, a quick
explanation: the 32 sectors/track is correct.
When Apple talks about 16 sectors/track, they
are refering to a “sector which contains 256
bytes. When CP/M refers to a sector, it is
refering to a "sector" of .128 bytes. Microsoft
(and thus Rana) handles this small difference in
interpretation of a sector” by packing two CP/M
sectors into every Apple sector (2 times 128
equals 256). Therefore Microsoft gets twice as
many (smaller) CP/M sectors on every track (32)
as Apple does (16). The actual way sectors” are
read and written from/to a diskette is iden-
tical between Microsoft CP/M, Apple DOS 3.3, and
Apple Pascal 1.1. This means that all three
systems can read and write the remaining two
systems’ diskettes, but they generally do not
understand the information which the other two
systems’ place within the “sectors”.
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