RISC OS 5 and software compatibility
Throughout its history RISC OS has used two different sets of processor modes, those that addressed 26-bits of memory and those that can address 32-bits. RISC OS 5 is the first OS version for the Risc PC era of machines to use 32-bit mode. This change first happened for other hardware in approximately 2003/2004 and caused a large portion of RISC OS software to cease functioning unless you updated it. If you were a RISC OS user after 2003 you may well have updated software that will run on RISC OS 5. If you wish to run older programs, then running RPCEmu with RISC OS 3, 4 or 6 will provide greater compatibility.
Throughout its history RISC OS has used two different sets of processor modes, those that addressed 26-bits of memory and those that can address 32-bits. RISC OS 5 is the first OS version for the Risc PC era of machines to use 32-bit mode. This change first happened for other hardware in approximately 2003/2004 and caused a large portion of RISC OS software to cease functioning unless you updated it. If you were a RISC OS user after 2003 you may well have updated software that will run on RISC OS 5. If you wish to run older programs, then running RPCEmu with RISC OS 3, 4 or 6 will provide greater compatibility.
This is the result of testing (As of 2018-05-03)
- RPCEmu 0.9.0
- ROOL RISC OS 5.24 ROM Image File: IOMD 5.24 stable (softload) - 2018-04-15. The ROM Image file required is inside the archive at the path soft/!Boot/Choices/Boot/PreDesk/!!SoftLoad/riscos The rest of the softload application is not needed with RPCEmu.
- ROOL self extracting hard disc File: HardDisc4 (self-extracting) - 2018-04-15 (RISC OS 5.24 stable version)
RISC OS 5 will run on RPCEmu however there are caveats.
Limitations
- Does not support IDE harddiscs or CDROM. [1]
- Selecting 'Shutdown' then clicking 'Restart' causes RPCEmu to exit with a 'Bad PC' error. Workaround - rerun RPCEmu
[1] Although the RISC OS ROM supports IDE, this has not yet been enabled on RPCEmu due to the presence of a RPCEmu data loss bug, that is only present when it is enabled.
Configuration
You can run a RISC OS !Boot sequence, using HostFS: Copy the HardDisc4 file to HostFS, boot the emulator, set the filetype to 'Utility' and run the file, this extracts the basic hard disc contents, into a sub directory called 'HardDisc4', move the contents to the root of the HostFS drive. Then type the following commands within RISC OS
*configure filesystem hostfs *configure boot
Reboot the system.