Also can one assume that a BBC emulator user, if asked to have Sideways RAM present that the commands *SRAM, *SRLOAD etc are standard? i.e. do PC emulators use these?
The situation on 6502em is confusing as to load a ROM you have to put it in the ROM directory, set it to BBCSnap filetype (as usual), double click on it then go to the desktop and click on the relevant space in the iconbar ROMS submenu. You can use a sideways RAM as Exile will run but how is it accessed?

Why does the OS ROM not show up in the configuration window of Beebit but it obviously loads as the emulator works and *HELP shows it?

The OS ROM for each emulated machine (BBC, Master etc.) is specified in the Options window. This is because the OS ROM is not a sideways ROM like the 16 other slots and does not get paged in and out of memory.

Also can one assume that a BBC emulator user, if asked to have Sideways RAM present that the commands *SRAM, *SRLOAD etc are standard? i.e. do PC emulators use these?

No. You would only get extra commands like *SRAM, *SRLOAD etc. if a sideways ROM was installed that gave those commands. On the Master they are build into the OS ROM.

The situation on 6502em is confusing as to load a ROM you have to put it in the ROM directory, set it to BBCSnap filetype (as usual), double click on it then go to the desktop and click on the relevant space in the iconbar ROMS submenu. You can use a sideways RAM as Exile will run but how is it accessed?

I don't know much about the workings of 6502Em. You should ask Mike, the author.

If you have other BeebIt questions, just email me directly as I very rarely read these forums.

I'm told that I have to page in the Sideways RAM to access it (I can save to it using *SRWrite) but having looked at a file version of the Advanced BBC User Guide all I can find is information on having to write a filing system for it to be able to access it.
The fact that Exile doesn't work expanded on the normal Beebit suggests to me it doesn't have its own SRAM FS but uses the standard SRAM *commands that come with SRAM or on the Master/B+.
Unfortunately I can't find an email for Mike Borcherds.
Thanks for them email offer anyway.

I think the reason 6502em will run Exile is that its 'Virtual DFS' has *SRWrite and *SRLoad built in but none of the other Sideways RAM utilities. Perhaps Exile makes use of these utilities on 6502em and the Master version of Beebit.

I'm pretty sure that Exile does not need the *SR commands to work because it is able to detect SWRAM and write directly to it. Exile should work fine with BeebIt in Model B mode with 1 or more banks of SWRAM enabled.

I'm told that I have to page in the Sideways RAM to access it (I can save to it using *SRWrite) but having looked at a file version of the Advanced BBC User Guide all I can find is information on having to write a filing system for it to be able to access it.

All you should need to do is write to memory location &FE30 the number of the RAM bank you want to access. Then you just need to write data to memory locations &8000-&AFFF. This works best using assembler. I don't think it works in BASIC.

The fact that Exile doesn't work expanded on the normal Beebit suggests to me it doesn't have its own SRAM FS but uses the standard SRAM *commands that come with SRAM or on the Master/B+.

It should work. If it detects SWRAM it will ask you if it can use the RAM.

Unfortunately I can't find an email for Mike Borcherds.

His domain is http://www.borcherds.co.uk/murklesoft/index.html. I'll email you his address soonish.

I'm told that I have to page in the Sideways RAM to access it (I can save to it using *SRWrite) but having looked at a file version of the Advanced BBC User Guide all I can find is information on having to write a filing system for it to be able to access it

It depends what you mean by 'access'.
Unless your writing a serious piece of software yourself, you shouldn't need to manually do this.
There's plenty of software in the OS/DFS to do this.
Ie *SRWRITE on the Master pages the SRAM in and out as required to perform the operation.