-ST Emulation on Firebee? -

[warp12]

I'm seriously considering a Firebee, from here in the states. I am curious, would it be possible to compile an emulator (Steem, Hatari, etc) to run classic ST(e) games? Does the Firebee have the hardware to support such an endeavor?

I know that market segment is not exactly the target, but it would be a nice perk for those who like the classics.

Shane

[joska]

I don't know if it's powerful enough to emulate a complete ST. But the Firebee doesn't have to. It has most ST-hardware, basically you only need to emulate the CPU and set up the Videl in "shifter-mode" to emulate an ST. Nobody has done it (yet) though.

[Zogging Hell]

Winston used to run at about 90-98% ST speed on my old Pentium 233mhz laptop with 64mb of memory and Windows 98, the Firebee has invisible OS comparatively, so surely something is possible (especially as there is less to emulate). Winston did quite a good job of running games, even though it isn't the most accurate or best of the emulators.

[Klapauzius]

I am curious, would it be possible to compile an emulator (Steem, Hatari, etc) to run classic ST(e) games? Does the Firebee have the hardware to support such an endeavor?

There may also be a chance to convert games 'natively' to the FireBee, without using a dedicated emulator. It's a bit too early to promise anything, but it's something I'd surely like to try.

I know that market segment is not exactly the target, but it would be a nice perk for those who like the classics.

Initially, I was thinking along the same lines. But don't worry, you're not alone with this wish.

[oehansen]

These instructions create illegal instruction exception, and they can be simulated in machine code. Here is a simple example ....

; MSB in D2 (for .B .W .L rotate), Count in D3 on entry
entry:
ror: lsr.l d0
bcc skip
or.l d2,d0
skip: subq.l #1,d3
bne.s ror

Of course it requires an exception handler, that decodes the instructions that generated the exception, and calls the emulations for these instructions. This should be quite doable, for at least the most "important" instructions, if not all ... but ROR/L I deem to be extremely important.

[Klapauzius]

FireTOS already has this kind of exception handling for the unimplemented 68k instructions and addressing modes, using the CF68KLib.

[Orion_]

I am curious, would it be possible to compile an emulator (Steem, Hatari, etc) to run classic ST(e) games? Does the Firebee have the hardware to support such an endeavor?

There may also be a chance to convert games 'natively' to the FireBee, without using a dedicated emulator. It's a bit too early to promise anything, but it's something I'd surely like to try.

I was wondering about the same thing, hacking the games like the awesome CT60 versions available on dbug or on your website.
That would be so cool to play good old ST game on firebee !

[oehansen]

FireTOS already has this kind of exception handling for the unimplemented 68k instructions and addressing modes, using the CF68KLib.

If it's in there, it sure ain't working ... they all create "illegal instruction", and "privelege violation" exceptions.

Such grab-ins are quite quick and easy to write, and I'd prefer the kernel having, than having it in user space ...

[Klapauzius]

There are a few special cases where an 68k instruction doesn't generate an exception, but still behaves differently on the ColdFire CPU.

For example, muls doesn't set the overflow flag in the ccr on the ColdFire.
Move.b dx,-(a7) decrements the stack pointer by one byte only on the ColdFire.
Probably the most problematic ones are the classic LineA calls on TOS - $a000 - $a00f. These are now valid MAC instructions on the ColdFire and don't generate an exception anymore.

All these can't be caught by an exception handler and will have to be patched manually.

Still, in my (short!) experience with the FireBee, many cleanly written 68k applications run just fine under FireTOS or FireTOS+Mint.

[oehansen]

I agree, most would ... but commands such as "ROR/L" are quite a nuisance that aren't implemented, and a lot of well written code will use them. They are quite common in implementing byte order reversal.

I took a look at cf68klib .... it's far too big to use. I think its a good idea, to change the code in the games.. And I'd also suggest having a "basic" handler, that would do the most needed instructions, like the rotate instructions, EXG, etc. The cf68klib source I read is 665250 bytes, and some 23819 lines. That is way too much ...

[BlankVector]

These instructions create illegal instruction exception, and they can be simulated in machine code.

If I understand correctly, you are complaining that FireTOS does not emulate ROL/ROR instructions.

In that case, you are wrong. FireTOS does emulate them through the CF68KLib.

However, sometimes FireTOS itself crashes and gets lost somewhere while it is in plain ColdFire mode, and messages such as "illegal instruction" are displayed. The original cause of the crash is elsewhere.

[joska]

I took a look at cf68klib .... it's far too big to use.

It seems to work just fine on the FireBee In what way is it to big?

[oehansen]

It seems to work just fine on the FireBee In what way is it to big?

That code is a monster, way too bloated it "appears" to emulate the XServer code ok.

The original cause of the crash is elsewhere.

ahemm ... cough cough

I have to admire Motorola/Freescale engeneers ... taking out ror/rol, instead of taking out either arithmetic or logical shifts. reading about the "compatibility" between the different versions of 68k, makes me feel like a junkie. if that makes any sense

[joska]

That code is a monster, way too bloated it "appears" to emulate the XServer code ok.

Here's a video of that monster running Arkanoid just fine: http://youtu.be/6B1xjo4VkyM

See http://acp.atari.org/.

[BlankVector]

[Klapauzius]

I recently got my FireBee, which is really a nice piece of hardware! However, because of the very different architecture of this machine, the current game patches unfortunately can't work on the FireBee.

After some fiddling around and getting lots of help from the nice people at the ACP (special thanks to Mathias and Vincent!), there is now a test version of Arkanoid for the FireBee available!

Please keep in mind that this version has to be considered as being in pre-alpha state, so some things don't work 100%, or not at all.

Here are the restrictions:

- USB keyboards and mice won't work in the game. You'll have to use Atari keyboards/mice or connect PS2 devices via an Eiffel interface.
- Some monitors may not support the FireBee's ST low screen resolution, the output timings generated by the FPGA are not 100% yet. If you get a black screen, try to use the VGA input on your LCD monitor by using a DVI->VGA adapter.
- You need to start the game from FireTOS or from Mint. Running the game from EmuTOS won't work, since there is no 68K emulation layer in EmuTOS.
- There will be slight flicker on some of the sprites here and there, due to the VBL interrupt not being synced to the monitor VBL (hard to fix, maybe some day).
- There's another minor bug in the FPGA/Videl that shifts the entire ST low picture down by one halfline. This is hardly noticeable in this game, though.
- Snapshots taken on the FireBee can't be restored on other machines (and vice-versa).

This is not much more than a proof of concept yet. Maybe we'll also see some sort of emulator on the FireBee for running ST games. In any case, there may be more game fixes coming for the FireBee from my side, but there are some issues that have to be solved before that.

This FireBee version should also work on 'normal' Ataris, it's a 'universal binary'

Get it here:
http://dbug.kicks-ass.net/klaz/Old_Games.html#Arkanoid
(it's the download link to the right)

[jfl]

After some fiddling around and getting lots of help from the nice people at the ACP (special thanks to Mathias and Vincent!), there is now a test version of Arkanoid for the FireBee available!

Oh Boy. This is insane. I tried it just out of curiosity since I was certain my LCD panel would not handle it but the game works perfectly! With sound and all! It's really amazing to see such an old game run so well on such a new machine. This tells a lot about all the work done by all involved in this project to make this possible.

[Mathias]

Oh Boy. This is insane. I tried it just out of curiosity since I was certain my LCD panel would not handle it but the game works perfectly! With sound and all! It's really amazing to see such an old game run so well on such a new machine. This tells a lot about all the work done by all involved in this project to make this possible.

Exactly, and Klapauzius is counting it still as "Alpha" software!! Incredible isn´t it?


If I consider what parts are still missing, it´s much more stunning that it became possible! I hope such insane support of the plattform is going on or even increasing, and a real killer machine will develope if we are all working together!

[Klapauzius]

Exactly, and Klapauzius is counting it still as "Alpha" software!! Incredible isn´t it?

That's mainly because USB keyboards and mice can't work in the game. I guess many people would like to use a shiny new and smooth USB optical mouse with their FireBee, instead of that old blocky Atari brick. I would, if I didn't have an optical mouse connected to the ST keybaord via the PeST.

If I consider what parts are still missing, it´s much more stunning that it became possible! I hope such insane support of the plattform is going on or even increasing, and a real killer machine will develope if we are all working together!

Yes, I hope so!

[Dal]

Tried running Arkanoid on my Bee and I get this:

Ark_FB_Error.jpg

[Mathias]

Two quick ideas:

1) Are you sure you got all the latest "Firemwares" (BaS, FPGA, FireTOS in this case) at your Bee? I know you got yours very early.

2) Did you wait at least 2 minutes after bootup, before you started Arkanoid?

[Dal]

I flashed the firmwares supplied on the CF card I got from Medusa a couple of weeks ago. I assume these are the latest?

I did not wait 2 minutes before trying to run the game. Didn't even know this was something that should be done - what's the reason?

[Mathias]

I flashed the firmwares supplied on the CF card I got from Medusa a couple of weeks ago. I assume these are the latest?

I hope so

I did not wait 2 minutes before trying to run the game. Didn't even know this was something that should be done - what's the reason?

I am not sure if it is still necessary. If so Klaz has to explain it, I didn understand it exactly
But does it work if you wait a little bit?

[wongck]

I am not sure if it is still necessary. If so Claus has to explain it, I didn understand it exactly
But does it work if you wait a little bit?

It may be it is the time for you to do the Happy "It will work on my FireBee" dance.
Did you not do that ?

[Klapauzius]

Dal, I had some issues with the self extracting program file format under FireTOS.
I thought these issues were gone now after changing the cache flushing code in the unpacker. Looks like there still might be something wrong with that.

Anyway, I have attached an unpacked version of Arkanoid to this post. Hopefully this will work for you.

PS:the 2 minutes wait should no longer be neccessary. It had to do with PCI drivers accessing the ST RAM shortly after booting or shortly after using the mixer.