| Function | Address | Description |
|---|---|---|
| READST | FFB7 | Read status word |
This routine returns the current status of the I/O devices in the accumulator. The routine is usually called after new communication to an I/O device. The routine gives you information about device status, or errors that have occurred during the I/O operation.
The bits returned in the accumulator contain the following information:
| Bit | Cassette Read | Serial Bus R/W | Tape Verify/Load |
|---|---|---|---|
| 0 | write timeout | ||
| 1 | read timeout | ||
| 2 | short block | short block | |
| 3 | long block | long block | |
| 4 | unrecoverable read error | any mismatch | |
| 5 | checksum error | checksum error | |
| 6 | end of file | EOI line | |
| 7 | end of tape | device not present | end of tape |
Example:
JSRREADSTCheck for end of file during read
AND#&40Check bit 6
BNEeofDetectedBranch on EOF