SAM Coupe core for MiST

[SirDavid]

Actually, this core is open source and anyone can add more features I prefer to focus on features giving some noticeable advantages.

I'd like to try, but first I have to learn how to build a core from your sources...

[Sorgelig]

New release:
- FDC code has been greatly reworked. Now you can write to both EDSK and MGT images.
- Remove SDF support to reduce complexity of code. SDF is superseded by EDSK. Use SAMdisk utility to convert it into EDSK.
Read the updated readme for more info.

[Sorgelig]

There is slight improvement in OSD when new firmware will be released. Instead Mount/Load *.DSK options, it will display Load Drive 1/2.

[SirDavid]

Meanwhile I have added back AY to the newest core, this time with changed address. And It works, all the demos I have converted once work! Who would have thought, I had no idea about programing FPGA until today

[schombi]

You´re crazy, guys! Thanks for your work.

Is there a way to learn FPGA programming resp. a guide and a list of what tools are needed?

[Sorgelig]

For Altera FPGA programming, the only tool you need is Quartus II: http://dl.altera.com/13.1/?edition=web
I didn't see comprehensive guide about FPGA programming. Google may help you

[ericgus]

For Altera FPGA programming, the only tool you need is Quartus II: http://dl.altera.com/13.1/?edition=web
I didn't see comprehensive guide about FPGA programming. Google may help you

Sorgelig, Under your "My cores for MiST" I dont see the most recent FPGA64 core you worked on .. i'd like to take a crack and playing with/compiling my own to learn fpga programming (since I know the c64 best of all).

[Sorgelig]

Sorgelig, Under your "My cores for MiST" I dont see the most recent FPGA64 core you worked on .. i'd like to take a crack and playing with/compiling my own to learn fpga programming (since I know the c64 best of all).

Because of author of FPGA64. He prohibit release the code.
Btw, how it's related to SAM Coupe topic?

[ericgus]

Sorgelig, Under your "My cores for MiST" I dont see the most recent FPGA64 core you worked on .. i'd like to take a crack and playing with/compiling my own to learn fpga programming (since I know the c64 best of all).

Because of author of FPGA64. He prohibit release the code.
Btw, how it's related to SAM Coupe topic?

schombi asked about learning to program FPGAs .. You suggested Quartus II and I was looking at your "my cores" to download one to try it with.. thats how.

[Sorgelig]

New release:
- Support multiple file extensions for disks. Now you can use native extensions for different formats.
- Support for IMG format used on ZX Spectrum (will be supported in next release of my ZX core).
- Improved write support. Now you can format the disk.
- Add SID support.

You must update to firmware 2016-06-19 (https://github.com/mist-devel/mist-bina ... r/firmware) or later for correct work of this release!

Please read updated Read Me for more details.

[NML32]

@Sorgelig thanks a lot for all the hard work you've put in to your cores.

[schombi]

Added SID support?!? Fantastic!

[Sorgelig]

SirDavid
i will check the game you've reported.

[Sorgelig]

The problem with keyboard in game Colony is unclear for me. Game simply has no any reaction on keyboard. I see there is keyboard scan, but why there is no reaction - i have no idea.
Game written in some high level language or in some game constructor - so it's extremely hard to find the source of problem.

If there any other game with keyboard problem then let me know. More games with similar problem - higher change to fix.

[Sorgelig]

OMG. This game compare keyboard port data against whole byte value instead of check separate bits.
And since tape input bit in my code is 0 instead of 1, none of keys matched in this game.

[Sorgelig]

New release:
- Fix disk formatting.
- invert RXMIDI and Tape-IN bits to suit some picky games.

[vebxenon]

New release:
- Fix disk formatting.
- invert RXMIDI and Tape-IN bits to suit some picky games.

Thanks as always

[SirDavid]

Unfortunately, i cannot increase CPU speed due to MiST using SDRAM. Unlike in other my cores where i could use FPGA RAM for video cache, SAM Coupe uses whole 512kb for video. So i had to use SDRAM for video. Since SDRAM require significantly longer time than SRAM to access the data, there is no time left for increasing CPU speed (unlike in ZX core where i could achieve 56MHz).
So, the only thing i could do is to disable CPU Throttle to allow CPU work at full speed (6MHz) whole time.

So how Amiga core can use higher CPU clocks and 2 MB of chip (video) RAM?

Anyway, original SAM Coupe didn't have 20MHz, so there should be no big loss.

Original SAM didn't have external RAM either. And higher CPU clocks are more useful then external RAM. There is an accelerator for SAM (called Mayhem Accelerator) and new demos can use it. It has two clocks: 10 and 20 MHz. Even 10 MHz in SAM core would be great...

[Sorgelig]

Full code is available on github. You are free to add higher CPU clocks and share with us.

[SirDavid]

I can share Quazar Surround soundcard (playing stereo) if you want, or anybody else wants, there are lots of software to play with it. For now my skills are far from enough to mess with RAM, CPU clock etc. I have tried but with no success. And I have no idea why. But if it works with Amiga core, it is not impossible.

[ericgus]

But if it works with Amiga core, it is not impossible.

I don't know the Coupe that well but believe it uses a z80 type cpu whereas the Amigas use a Motorola 68K family processor so you can't really make that sort of assumption.. apples to oranges comparison here.. those techniques and the logic core for the M68K cpu core wouldn't work here, you would need a fpga z80 core that is purposefully designed to run at a fast clock rate. I know it would be nice to think its just simply changing some number in a source code file to whatever new speed you like but it doesn't work that way.

[vebxenon]

Sam Coupé uses a Zilog Z80B at 6 MHz.

[Newsdee]

There's all kind of side effects that could happen if one cranks up CPU speed without adjusting the rest; especially for these earlier architectures that weren't designed for it (unlike a modern PC designed to accomodate a very wide range of processor speeds)

[Sorgelig]

I've added turbo 12MHz and 24MHz, but these two demos (SlowMotion 1,2) originally should benefit from turbo, in reality have problems.
I don't know HW details of that Mayhem Accelerator. If it replaces system memory by static RAM, then CPU can have very high clock without contention. In MiST we have only SDRAM which is much slower than SRAM and should serve the video as well. Thus turbo modes (i.e. 12MHz and 24MHz) cannot avoid contention. Although these turbos are faster than original 6MHz mode, they are not at 100% of their speeds (90% of 12MHz, 60% of 24MHz). May be this contention(throttling) confuses these demos if there are some timing calculation used inside.

[SirDavid]

Great anyway! Can you share it?