OS_Byte 156 (changes)
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Programmer's OS Reference SWI Manuals Calls
» Part OS_Byte 15 – SWI Calls
» OS_Byte 156OS
» OS_Byte
» OS_Byte 156
OS_Byte 156
(SWI &06)
| Entry | |
|---|---|
| R0 | 156 (&9C) |
| R1 | EOR value |
| R2 | AND value |
| Exit | |
|---|---|
| R0 | Preserved |
| R1 | State before being overwritten |
| R2 | Keyboard disable flag (see OS_Byte 201) |
Use
The purpose of this call is to read or write the serial port state.
Notes
This call is now deprecated. Please use OS_SerialOp 0 and OS_SerialOp 1 to change the receive interrupt/control bit instead.
When writing, the effects depend on R1:
| Bits | Value | Effect |
|---|---|---|
| 0 – 1 | 0 – 2 | No effect |
| 3 | Reset transmit, receive, control registers | |
| 2 – 4 | 0 | 7 bit, even parity, 2 stop bits (7E2) |
| 1 | 7 bit, odd parity, 2 stop bits (7O2) | |
| 2 | 7 bit, even parity, 1 stop bits (7E1) | |
| 3 | 7 bit, odd parity, 1 stop bit (7O1) | |
| 4 | 8 bit, no parity, 2 stop bits (8N2) | |
| 5 | 8 bit, no parity, 1 stop bits (8N1) | |
| 6 | 8 bit, even parity, 1 stop bits (8E1) | |
| 7 | 8 bit, odd parity, 1 stop bit (8O1) | |
| 5 – 6 | 0 | RTS low, transmit interrupt disabled |
| 1 | RTS low, transmit interrupt enabled | |
| 2 | RTS high, transmit interrupt disabled | |
| 3 | RTS low, transmit interrupt disabled, break level on transmit data | |
| 7 | 0 | Receive interrupt disabled |
| 1 | Receive interrupt enabled |
You should only write bit 7 with this call (and really should be using OS_Byte 2). The value can also be read with OS_Byte 192.
The default value for bits 2-4 is stored in OS_Byte CMOS 16.
See also
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