exxos's Atari, Amiga & retro forum

That's getting pretty quick.

Badwolf wrote: 21 Jun 2023 12:08 * Have you noticed how most of exxos' smilies are about frustration and beating people up? This is the best I could come up with for gobsmacked and blown away :P

:smoke: :chairsmack:

@dad664npc That is some seriously cool work there. 8-)

exxos wrote: 21 Jun 2023 12:36

Badwolf wrote: 21 Jun 2023 12:08 * Have you noticed how most of exxos' smilies are about frustration and beating people up? This is the best I could come up with for gobsmacked and blown away :P

:smoke: :chairsmack:

What Exxos means to say, is that you must have a sore head (like you've been hit repeatedly with a deck chair) after all that hard work. :lol:

Amazing work. I hope that it becomes stable enough to be a usable accelerator. (If it is already, hats off)

dad664npc wrote: 21 Jun 2023 11:53 whilst stepping through the [emulator] code I realised that a lot of optimisations could be made. So implementing these changes to the non-baremetal code, performance has increased A LOT!

Are these optimisations being pushed upstream? I'm sure they would be very well received.

I think it's fairly stable. I can run all CPU variants with differing ROMs. Run various benchmarks on each. I can run Mint on 68030 and 68040.
The next stage is to get a few more users and test a bit more. Then we need to look at a bespoke hardware solution for the Atari.

Even a PI4 clocked at 1.5 GHz now offers good performance - CoreMark 36.18, Elite FB 2980
And if you crank it right up to 2.3 GHz - CoreMark 57.04, Elite FB 3391

GitHub is up to date - https://github.com/gotaproblem/pistorm-atari

And I have made a little more progress on the bare-metal version. I can now boot in to GEM - but it is painfully slow. Need to figure out the cache and MMU settings - so if anyone knows about that stuff...

dad664npc wrote: 23 Jun 2023 06:49 I think it's fairly stable. I can run all CPU variants with differing ROMs. Run various benchmarks on each. I can run Mint on 68030 and 68040.
The next stage is to get a few more users and test a bit more. Then we need to look at a bespoke hardware solution for the Atari.

Fantastic work!

And I have made a little more progress on the bare-metal version. I can now boot in to GEM - but it is painfully slow. Need to figure out the cache and MMU settings - so if anyone knows about that stuff...

Slow in what way? Do you mean the ARM cache and MMU? 68k has neither, obviously.

BW

Slow in what way? Do you mean the ARM cache and MMU? 68k has neither, obviously.

Slow as in it takes several minutes to draw anything on the screen. I have configured the clocks for CPU=1.5 GHz and GPU=750 MHz and have confirmed they are set.
Yes the ARM side of things. What I have for enabling data and instruction caches does not do anything. I read somewhere that the PI MMU has to be enabled before cache can work. But trying to find info on this for 32 bit bare-metal isn't easy. Might have to try aarch64 again.

dad664npc wrote: 23 Jun 2023 10:00

Slow in what way? Do you mean the ARM cache and MMU? 68k has neither, obviously.

Slow as in it takes several minutes to draw anything on the screen. I have configured the clocks for CPU=1.5 GHz and GPU=750 MHz and have confirmed they are set.
Yes the ARM side of things. What I have for enabling data and instruction caches does not do anything. I read somewhere that the PI MMU has to be enabled before cache can work. But trying to find info on this for 32 bit bare-metal isn't easy. Might have to try aarch64 again.

Ah. I know more Welsh than I do ARM. Presuambly Emu68 has had to tackle the same? Can you crib anything from that?

https://github.com/michalsc/Emu68/tree/master/src/raspi

BW

Also Michal the dev of emu68 is very available & helpful on the Discord, speaking directly to him might be a good idea!

I do speak to Michal but do not find him helpful at all. Maybe I'm asking the wrong questions :?