bbc basic in unicorn

Only simulating input and output swi’s, so it is a bit limited in what it can do.
I built basic to binary. The emulation starts at MAIN (by giving the offset). No
MMU is used.

Brilliant! You can emulate ARM and run BBC BASIC on the Brexit Unicorn. Whodathunkit?

Seriously, though, what’s a unicorn? Google… shows me a lot of rainbow coloured horse-like creatures.

Hmmm, the magic combination that Google likes is “unicorn processor”, and that led me to https://www.unicorn-engine.org/

Yes sorry for not explaining. Unicorn Engine is a cpu emulator that runs on many platforms. My approach is to use the cpu emulation for the main program , in this case standalone basic. All swi replies are done in host code.

Just did OS_File 255 which gave med LOAD :)

I don’t know how far this can go. In theory the platform will be more or less cpu agnostic with a lot of code running inside the hosts native code.

I don’t know how far this can go.

About as far as keeps your interest. ;)

In theory the platform will be more or less cpu agnostic

Hmm, 32 bit RISC OS, 64 bit ARM…?

By the way, your screenshots indicate you are running in immediate mode and giving commands directly to BASIC.
What happened to the ‘>’?

By the way, your screenshots indicate you are running in immediate mode and giving commands directly to BASIC.
What happened to the ‘>’?

I wonder that too … need to check , I have hacked a bit in the BASIC sources.. maybe managed to remove it.

Found it , the “>” is printed with OS_PrintI which I don’t support right now.

And there it is:

👍 Now that looks right.

I can also play games!

How does Unicorn compare with qemu?

How does Unicorn compare with qemu?

Well, Unicorn is a cpu only emulator (from my understanding). Also easy to use. It also have JIT , platform independent I think.

LOAD,SAVE,TEXTLOAD and TEXTSAVE are working now, was a bit of mess until I found out that I was missing a SWI. Thanks to Nemo for pointing it out.

Now with WiMP support ( very limited )

The window gets created in Wimp_Initialize , and that will change.
The event loop works. When window is closed , relevant bits are poked to wimp block , and reason code is updated.

Good luck with menus.

I had a half-assed crack at writing a clone of Arthur’s Wimp a couple of Christmases ago.
There was a lot left undone (writeable icons, key presses, proper window redraws…), but the big one I glossed over was making menus on the fly.
It’s not as simple as it looks. ;)

https://heyrick.eu/blog/index.php?diary=20201227#rarthur if you’re interested.

https://heyrick.eu/blog/index.php?diary=20201227#rarthur if you’re interested

Nice project! I am sure that I will fail sooner or later. But I think that a hosted environment is better than a completely emulated system.
I want to make use of the hardware as much as possible.

In !GraphTask there is program called !DEEJsys I wrote for the BBC Master in the summer of 1987 after I’d seem a picture of the Arthur desktop in the Acorn User magazine. Because I hadn’t got an Archimedes and used Arthur at that point, it doesn’t quite work the same, but I think a desktop in a 320×160 4 colour mode in 20K of BASIC isn’t too bad.

You undersell yourself druck. For “isn’t too bad” read “bloody good”.

First sign of ARM module support:

Hijacking SWI numbers, since I do not have a prompt.

Loading Draw module :)

SWI lookup , in which module is it? Using PineTools as test module.