OSWORD &FA (250) - Data transfer over Tube (80x86 Tube OS)
On entry: XY?0 =&0D or &0E (send block length) XY?1 =&10 (receive block length) XY!2 =I/O processor address XY+6..7 =80x86 offset address XY+8..9 =80x86 segment address XY+10..11=data length XY?12 =function XY?13 =memory access control if XY?0=&0E.
The functions are the same as the Tube values:
- 0 - write to I/O as single bytes
- 1 - read from I/O as single bytes
- 2 - write to I/O as byte pairs
- 3 - read from I/O as byte pairs
- 6 - write to I/O as groups of 256 bytes
- 7 - read from I/O as groups of 256 bytes
If the memory access control byte is not used the I/O address at XY!2 accesses the main I/O memory and whichever ROM happens to be paged in when the call is made - usually the current language. If the memory access control byte is used, its format is:
- b0-b3=ROM number
- b4 =0 use specified ROM, b4=1 use current ROM
- b5 =0 use main memory, b5=1 use screen memory
- b6 =1 ignore b5 and use shadow memory
- b7 unused.