Amstrad DDI-1 Computer Drive User Manual


 
Errors detected by the floppy disc controller are reported as a bit significant value
between #40..#7F, i.e. bit 6 is always set. The other bits are returned as follows:
bit 5 data error - CRC error on data or ID field.
bit 4 overrun error.
bit 3 drive not ready - there is no disc in the drive.
bit 2 no data - can't find the sector.
bit 1 not writable - disc is write protected.
bit 0 address mark missing.
5.9 Intercepted Firmware Calls
The intercepted firmware calls are:
Reading Files
125
#BC77
CAS IN OPEN Open a file for input
126
#BC7A
CAS IN CLOSE Close the input file properly
127
#BC7D
CAS IN ABANDON Close the input file immediately.
128
#BC80
CAS IN CHAR Read a character from the input file.
129
#BC83
CAS IN DIRECT Read the input file into store.
130
#BC86
CAS RETURN Put the last character read back.
131
#BC89
CAS TEST EOF Have we reached the end of the
input file yet?
Writing Files
132
#BC8C
CAS OUT OPEN Open a file for output.
133
#BC8F
CAS OUT CLOSE Close the output file properly.
134
#BC92
CAS OUT ABANDON Close the output file immediately
135
#BC95
CAS OUT CHAR Write a character to the output file.
136
#BC98
CAS OUT DIRECT Write the output file directly from
disc.
Cataloguing
137
#BC9B
CAS CATALOG Generate a catalogue from disc
Chapter 5. 7 AMSTRAD Disc Drive & Interface DDI-1 Manual