IP Networking and DNS Resolution

OSWord call Action Available on:
(dec) (hex)Other
192 C0 IP Networking and DNS ResolutionSPROW Ethernet for BBC Master

This call is supported on the Network API documentation for the SPROW Ethernet upgrade for the Master Series which I happen to have installed in my BBC Master 128.

This call is modelled on the Berkeley Sockets API.

Call format

The control block follows the convention for high-numbered OSWORD calls where the control block contains the request & response sizes, action and result codes as the first 4 bytes of the block.

XY+ On entry On exit Range
0 send block length, depends on subreason code preserved 0x02…0x7F
1 return block length, depends on subreason code preserved 0x02…0x7F
2 action set to zero
3 must be zero result
4… request data result data


To allow for many functions to be performed but without using up lots of OSWord numbers a one byte action code is included, allowing for up to 256 different pieces of functionality. The action codes are further split into groups of 64 each:

Action (range) Functionality
0x00…0x3FSocket operations
0x40…0x7FResolver operations
0x80…0xBFReserved for future use
0xC0…0xFFReserved for future use

Unused or reserved action codes will return an error number at XY+3.