Sideways RAM Under Emulation

By John Crane

Originally published in EUG #56

In EUG #55, Chris Dewhurst was seeking advice on Sideways RAM and, whilst I'm no expert, I have had some experience in its use, on an A3010 at least. !65Host, with or without SWR, can also be persuaded to work on a Strongarm RiscPC, despite what many people say to the contrary. Not sure about Risc OS4 though.

!65Host can be made to emulate SWR on a BBC, but the instructions supplied are, I think, somewhat vague.

It firstly needs setting up, as it doesn't run by default:

  1. Hold down the SHIFT key and double-click on the !65Host program icon to open it (rather than run it). This will open up a display containing its sub-directories and files.
  2. Hold down SHIFT and double-click on !Run to list the run file. You can have four SWR slots enabled in one of two groups 4, 5, 6, 7 or 0, 1, 14, 15. NOT all 8. And the numbers must be in those specific groups.
  3. Scroll through the file until you find the group you wish to enable and remove the | at the beginning of that line to make it active and re-save the updated !Run file. Close the !Run file, and close !65Host.
  4. Now to use SWR under emulation, double-click on !65Host in the normal way to run it.
  5. At the BBC > prompt, navigate to where you've stored your ROM image and type the following :
          > *SRLOAD xxxx 8000 4 
    (where xxxx is your ROM image filename and 4 is the SWR location you wish to use. Obviously this could be 4, 5, 6 or 7 of if you enabled the alternative set: 0, 1, 14 or 15.)

    Note that the figure after your filename must be 8000, for this to work.

    After typing press CTRL-BREAK, otherwise your SWR will not be loaded.

  6. I then usually do a *ROMS to make sure it has successfully loaded, as it doesn't always seem to work first time. If your SWR ROM image name is listed next to the location you specified (4, 5 or whatever) then it's loaded.
I have found that while you can get most ROM images to load, not that many seem to actually work.

The View family do, but they need a little bit of tweaking, but this is true whatever SWR you use it in. That is, they even needed tweaking on 'Real BBCs', i.e not emulated ones.

If you're interested in tweaking View, Viewsheet, etc I can help out. But you can get better performance from them on an A3010 by use of a little utility which enables you to run them straight from the desktop. You can even print out from view (*WORD) with a bit of jiggery pokery. I use this myself to submit articles to EUG. Providing you remember to format your disk to ADFS 640k (L), you should be fine.

If you need to format down to an ADFS M format, which is not supported on the A3010, I have a little utility for that too. It's also PD.

Anyway, if I can be of further assistance, just let me know.

John Crane, EUG #56