Apple 13-0010--001 Computer Drive User Manual


 
ELITE SERIES USER MANUAL CP/M ENHANCEMENTS
city (if you’re an Elite Two or Three user, this
will make your day), look up the:
STAT DSK: <RETURN>
command in your Microsoft CP/M manuals. For a
Disk ][ drive, STAT will respond with the fol-
lowing:
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
4—37