© nemo 2002-2018

WriteReg is a debugging module that displays the contents of any register, or the processor flags.

The current version is 1.03 (16 May 2018) [32bit]

This version is not compatible with RISC OS 6.20

This module provides a number of SWIs for displaying the contents of any register without side-effects. As well as the usual parameter registers it can display R10-R15, plus the flags, CPSR and SPSR. It will even display the SWI’s X Flag... because it can.


Write_R0 - Write_R15

Displays the contents of the user register. In the case of R14 and R15 in 26bit modes, this will include flags. The value is displayed as an 8 digit hexadecimal number followed by a space.


Displays the user’s PC in hex. This never includes flags.


Displays the flags and mode in hex.


Displays the flags as four characters followed by a space.

Write_CPSR, Write_SPSR

Displays the CPSR and SPSR in hex on those processors that support them.


Tells you in hex whether you called Write_X or XWrite_X. This is more clever than useful.