Commodore 1570 - Page 96

SWITCHES: P-sequential file bit (P = 1, does not have to be a program file)
X---don't care
PROTOCOL: Burst handshake
OUTPUT: Burst status byte preceding each sector transfered. Track and sector for
link are
automatically treated. In a program file, the loading address should
be handled
correctly.
STATUS IS
AS FOLLOWS: 0000000X-OK
00000010--file not found
00011111-EOI
Any other status byte should be considered a file read error.
STATUS
BYTE BREAKDOWN
BIT 7 6
5 4 3 2
o
MODE DN
SECTOR SIZE
CONTROLLERSTATUS ]
MODE-l =MFM, O=GCR
DN -DRIVE NUMBER
SECTOR
SIZE-(MFM ONLY)
00 ........ 128 BYTE SECTORS
01 ........ 256 BYTE SECTORS
10 ........ 512 BYTE SECTORS
11 ........ 1024 BYTE SECTORS
CONTROLLER STATUS (GCR)
OOOX ..... OK
0010
...... SECTOR NOT FOUND
0011
...... NO SYNC
0100
...... DATA BLOCK NOT FOUND
0101
...... DATA BLOCK CHECKSUM ERROR
0110
...... FORMAT ERROR
0111
...... VERIFY ERROR
1000
...... WRITE PROTECT ERROR
1001 ...... HEADER BLOCK CHECKSUM ERROR
1010
...... DATA EXTENDS INTO NEXT BLOCK
1011 ...... DISK ID MISMATCH/DISK CHANGE
1100
...... RESERVED
1101 ...... RESERVED
1110
...... SYNTAX ERROR
1111 ...... NO DRIVE PRESENT
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