MIST Experience with Atari 8 Bit

[Newsdee]

I have a MiST and a MiSTer. I find them more enjoyable to use than software emulators because of the simplicity of setup and instant-on. I agree with Keatah though than in terms of "amenities" they have less than emulators, however they have more than real hardware.

 

Today I'd be inclined to recommend a MiSTer cover the MiST (cheaper) but if you want a clases box, there are interesting MiST clones (like the MiSTica16 with composite and svideo out)

[Level42]

My only real experience with FPGA's are those that were made for a series of Williams arcade games.

Most of Williams' games used more or less the same hardware and thus it was interesting to make a FPGaa for it to play more of the games on one machine or if not for that, to replace (missing) game PCBs for real machines.

 

Later there was also a FGPA board for Gottlieb games, mainly Q*bert and related.

 

What is noticsvle about these is that they still used a real physical original processor. All the other stuff was FPGA'ed so I'm pretty sure the developer never got any of the processor cores to run as good as the real thing. Those boards had VGA OUT, but also the original RGB signals so they can be hooked up to the original monitor without any problems.

 

The feeling of these games was 100% original to me. And I am talking games like Robotron, Joust etc. which are both fast and requiering extremely quick controls. I'm not a pro gamer, but I could not see, hear or feel any difference.

 

The big difference between FPGA and software emulation is that emulation is still (however fast) a sequential thing. FPGA mimics the real hardware, there is NO time difference with real hardware.

 

So, in theory FPGA would be the closest to real hardware. If things do not work exacly like the real hardware, there must be something incorrect about the FPGA cores used. The fact that the arcade FPGA cards use a real processor indicate there were probably issues with the FOGA core of those processors.

 

For me real hardware I'd about 90% of the fun about this hobby and I shiver with the idea of people only running emulation. Emulation is nice to try out some stuff quickly, but it will never give the real feel for me. Not to mention you can never use a proper CRT with emulation (well not without a lot of hassle)

[Level42]

Here's Jrok's website with the arcade FPGA boards I mentioned:

 

http://www.jrok.com/hardware/wsf/

 

He now has done versions for Berzerk/Frenzy and Zoo Keeper/Qix too....

 

Forgot to mention: those boards blew away ANY arcade emulation I've ever seen. Absolutely no lag.

Emulation was never an option for me to put in an original dedicated cab, but I did own two Williams FPGA's because I had found two Williams cabs with the PCBs missing. If possible I'd run the original boards though.....nothing more magic than having the original hardware running....

[Newsdee]

There are several open-source arcade cores; and a bunch of them have been ported to the MiST and MiSTer.

Here's a list for MiSTer as of today (from https://github.com/MiSTer-devel/Main_MiSTer/wiki )

 

I should add that both boards are able to output a 15khz RGB signal from the VGA port, allowing to connect to CRT and arcade monitors with just the proper cabling.
There is also the option to output to component (YPbPr) with a small adapter circuit.

 

MiSTer arcade cores

• Alibaba and 40 Thieves
• Amidar
• Bagman
• Black Hole
• Bomb Jack
• Computer Space
• Cosmic Avenger
• Crazy Kong
• Crush Roller
• Defender
• Dorodon
• Dream Shopper
• Eeekk!
• Eyes
• Frogger
• Galaga
• Galaxian
• Gorkans
• Lady Bug
• Lizard Wizard
• Moon Cresta
• Moon Patrol
• Mr.Do's Nightmare
• Mr.TNT
• Ms.Pacman
• Orbitron
• Pacman
• Pacman Club
• Pacman Plus
• Pacmanic Miner
• Pengo
• Phoenix
• Ponpoko
• Pooyan
• Scramble
• Snap Jack
• Super Glob
• Time Pilot
• Van-Van Car
• Woodpecker
• Xevious

Edited December 3, 2017 by Newsdee

[Level42]

Cool. But I'd love to see some timing measurements compared to the real hardware....

[ijor]

So, in theory FPGA would be the closest to real hardware. If things do not work exacly like the real hardware, there must be something incorrect about the FPGA cores used. The fact that the arcade FPGA cards use a real processor indicate there were probably issues with the FOGA core of those processors.

 

The processor on these fpga clone boards is not (normally) used as part of the emulation/cloning. It is used because it is much more convenient for processing such things as presenting the menu to the user, accessing files on a SD card and managing PS/2 or USB input.

 

You could avoid the processor and perform those tasks with the FPGA if you want. But it's not efficient, and it doesn't makes much sense since this is beyond the original hardware.

[foft]

 

The processor on these fpga clone boards is not (normally) used as part of the emulation/cloning. It is used because it is much more convenient for processing such things as presenting the menu to the user, accessing files on a SD card and managing PS/2 or USB input.

 

You could avoid the processor and perform those tasks with the FPGA if you want. But it's not efficient, and it doesn't makes much sense since this is beyond the original hardware.

One benefit of putting the control cpu in is portability to other boards. There are many fpga boards and they rarely have the same companion cpu setup.

[ijor]

One benefit of putting the control cpu in is portability to other boards. There are many fpga boards and they rarely have the same companion cpu setup.

 

May be. Surely it has some pros, but probably has more cons. Anyway, my point was that the presence and usage of an external CPU doesn't mean at all that there are some issues with the FPGA core, as Level42 assumed.

[Grevle]

My biggest problem with Emulation is the joystick input lag, Direct 3d always seem to add some noticeable input lag, If you can use Windows XP and have a emulator that supports directdraw fully then the lag is lesser but Still the Mist FPGA specially when used in 15khz connected to a Crt screen the input response is very close to the real Hardware.

 

I have done some tests on CRT Screen and came to these conclusions about input lag:

 

Real Hardware = Spot on as you would expect. I believe real Hardware have only one frame lag.

Mist FPGA = Close as you can get to the real thing. I tried comparing Real Hardware and Mist FPGA and its very close.

Emulator on Winxp with directdraw = Can be petty good if the emulator supports directdraw. This is on Flat pc Gaming monitor, the monitor itself adds just a very tiny bit of lag it seems.

Emulator With Direct 3D. There is more noticeable lag, Specially if you appreciate Retro gaming at its purest form.

 

Heres some facts : Mist FPGA Atari core cannot support Light gun because the way the input port need to be read is to demanding.

Real Hardware is champ with light Gun and Paddles.

Mist Can support paddles via USB using the 2600 daptor, Which i also tested and it works pretty good but there is a noticeable difference between Real hardware and mist.

 

One big advantage with Mist Atari Core is the ability to support PAL and NTSC cores, So you can switch between PAL and NTSC when using software designed for one or the other.

For PAL having real 50hz on a CRT screen makes it very authentic.

Also the is many other good cores for Mist, The C64 Core have come a long way, The Nes core is very good, Atari 2600 works good, but need more work. The Amiga Mist core is probably the most advanced one and its pretty awesome. The Atari ST core works good. Coleco core and so on. All these support 15khz for CRT tv. I'm bit of a CRT fanatic and wouldn't use it any other way.

 

So Mist FPGA is pretty close to perfect, For Atari 8bit core the sound could be better, and then Light gun support totally lacking, for that probably a more powerful FPGA would be needed, Maybe Mister have the capability.Paddles support via 2600daptor USB works but leaves a little to be desired for perfection.

 

Still i really enjoy the Mist FPGA Atari core and the other system cores as well.

Edited December 3, 2017 by Grevle

[_The Doctor__]

Very accurate run down, thank you for paying such attention to detail, this information shoud be shared with the Ataribox people as well. You put everything is a fashion that is very understandable! Nicely stated, nicely summed up.

Edited December 3, 2017 by _The Doctor__

[Grevle]

I also believe that Windows 8 and windows 10 USB Routines is more optimized , so using usb controller with windows 10 would work better than using USB controller with win XP, so then its like these two things works against each other like this, Win 10 better for USB controllers , But win 10 does not have proper support for Directdraw, Versus Win XP have full support for Directdraw, But the USB routines is not as optimized., The solution ? Well after extensive use and testing of emulators, Using WinXP With A PS\2 keyboard adaptor like the I-PAC, And a emulator supporting Directdraw gives the best input response, for me, other may have other solutions. The newest I-PAC doesn support PS\2 anymore, only USB. The keywiz is the only keyboard adaptors still supporting PS\2 i believe.

 

Such keyboard adaptors makes it possible to connect various joysticks via the PS\2 Port.

 

Still mist FPGA comes out better that any emulator i tested for Input lag.

 

Using mist with a flat screen modern monitor is a different story, Because the monitor have to scale to the resolution used by mist and this scaling takes a litte time with then means it adds lag to the controller. A Crt screen doesn't need scaling , Mist can output native resolution and the CRT screen support it native without no scaling, and support both 60hz for NTSC and 50hz for Pal properly, And the crt screen have real scanlines.

Edited December 3, 2017 by Grevle

[Level42]

 

May be. Surely it has some pros, but probably has more cons. Anyway, my point was that the presence and usage of an external CPU doesn't mean at all that there are some issues with the FPGA core, as Level42 assumed.

 

I meant to say that running a processor core in FPGA caused issues compared to running a real physical one and "only" put all the other hardware in the FPGA.....and I think that was exactly what you confirmed

Edited December 3, 2017 by Level42

[Newsdee]

So Mist FPGA is pretty close to perfect, For Atari 8bit core the sound could be better, and then Light gun support totally lacking, for that probably a more powerful FPGA would be needed, Maybe Mister have the capability.Paddles support via 2600daptor USB works but leaves a little to be desired for perfection.

 

Light gun support is more a matter of having the core handle it rather than FPGA limitations. The Analogue NT mini (for example) uses an FPGA that has a similar size to the MiST and has light gun support on CRT TV's.

 

I think the issue is that nobody has looked at that problem yet, and also perhaps there isn't much incentive to do so when using a mouse to emulate it could be a more generic approach (there are modern light guns that translate to mouse handling now).

[ijor]

I meant to say that running a processor core in FPGA caused issues compared to running a real physical one and "only" put all the other hardware in the FPGA.....and I think that was exactly what you confirmed

 

I might have misunderstood you, sorry. But it is perfectly possible to put the processor in the FPGA. As a matter of fact, Foft's Atari core does precisely that, even at the MIST. But a soft processor takes precious space on the FPGA.

 

Light gun support is more a matter of having the core handle it rather than FPGA limitations.

The problem of Light gun is that the trigger needs to be connected directly to the FPGA, and not to the CPU as is the case with the MIST. It could have been done, but guess it was deemed not very important.

[Newsdee]

 

The problem of Light gun is that the trigger needs to be connected directly to the FPGA, and not to the CPU as is the case with the MIST. It could have been done, but guess it was deemed not very important.

There are some free FPGA pins that can be used

 

On the MiST I think one needs to disable the MIDI, which has been done to support an "Ear" (audio in) input for Spectrum cores. The MiSTer I think still has some unassigned pins.

 

The problem though is that none of the cores are wired for.that. Can be done in theory but needs a keen developer. I do have both boards and a Zapper, if any developer wants a keen beta tester / guinea pig

[foft]

The core itself supports the light gun, just needs wiring to a pin - careful of the 5V though since that would break the fpga.

 

On my mist dev board the midi pins go to the rs232 port...

 

Back to the external cpu vs soft core. I tried out the SOCkit a while back. ie the cyclone v with integrated arm. It was pretty cool to be able to map the atari core onto the arm bus. I struggled with latency issues due (I think) to running Linux on the arm.

[ijor]

Back to the external cpu vs soft core. I tried out the SOCkit a while back. ie the cyclone v with integrated arm. It was pretty cool to be able to map the atari core onto the arm bus. I struggled with latency issues due (I think) to running Linux on the arm.

 

Latency on what? The input controllers or accessing the SD card? I don't know if Linux introduces a significant latency. But in the worst case you are not forced to run Linux. You can run a real time OS, or even bare metal. The flexibility of running full Linux is extremely powerful, though.

[foft]

Not sure, I stopped developing on it because the jtag port fell off and I was already frustrated with several things! For example no-one had a working example of using the ddr3 ram fpga side without qsys. I think I was suffering from dropped sio bytes - I was using a pokey to receive without fifo though, so not much leeway!

Edited December 4, 2017 by foft

[Grevle]

The core itself supports the light gun, just needs wiring to a pin - careful of the 5V though since that would break the fpga.

 

On my mist dev board the midi pins go to the rs232 port...

 

Back to the external cpu vs soft core. I tried out the SOCkit a while back. ie the cyclone v with integrated arm. It was pretty cool to be able to map the atari core onto the arm bus. I struggled with latency issues due (I think) to running Linux on the arm.

 

OK . I did not know that, I was under the impression that Light gun would be hard next to impossible to implement. Sorry about that. About that wiring ? could it be wired on mist fpga board and how many wires and where on the board ?. is it only possible on the Mist version with midi port ? Thanks.

[Newsdee]

is it only possible on the Mist version with midi port ? Thanks.

It's possible on all boards; what happens is that the MiST has four "extension" pins that are normally used for the MIDI ports, but some cores have given those pins other purposes. For example, you can use the pins to plug an audio-in connector (e.g. the Spectrum "EAR"). One needs to disconnect the MIDI ports for it to work, though.

 

Originally these pins were for serial UART communication for debugging, but that is only used by developers so they were put to better use. The MIDI is very important for Atari ST people for example.

Edited December 11, 2017 by Newsdee

[Keatah]

It likely goes without saying.. but.. If the cores are of sufficient accuracy and if they model and emulate the original system's circuitry in all details (they do not), then "lightgun support" would simply happen as a matter of default.

[foft]

It likely goes without saying.. but.. If the cores are of sufficient accuracy and if they model and emulate the original system's circuitry in all details (they do not), then "lightgun support" would simply happen as a matter of default.

True, though it would still have the issue of needing to be wired to a pin.

 

Re simplicity: On the mist core side its not connected to midi in, so the core would also need rebuilding.

[Level42]

That MiSTer looks a lot more interesting than the MiST. Never heard about it before.

 

Since "everything" is on FPGA A8 wise on these machines: why can't anyone create an FPGA POKEY-only ?

[Newsdee]

That MiSTer looks a lot more interesting than the MiST. Never heard about it before.

It's a successor device of sorts. It was made possible by off-the-shelf FPGA boards being cheap enough to be great alternatives to the MiST's 100% homebrew board. Same community around it though. Edited December 11, 2017 by Newsdee

[ianoid]

I have been spending a bunch of time getting my MIST unit loaded up, with the last core I really want to figure out being the Atari 8-bit one. If anyone understands how I'm supposed to set it up, do tell. When I try to load a disk image in the on screen menu, it has a non-standard approach, I think requiring some kind of database, and using the Atari font rather than the system font.

 

----

 

There is little active development happening for the original MIST system. The MISTer has a great deal more going on as far as core development goes. The "core" is the system you want to run on the FPGA. So for example, you need an Atari 800 core (which is usually just a single file you leave on the SD card root directory, sometimes with a few additional ROM files in a specific location on the SD card) to run Atari 8-bit stuff on your FPGA. The core shuts down when you turn off the system and is reloaded when you power it up. You can choose different cores easily when you startup the unit by a simple menu.

 

Some thoughts if you are interested in using FPGAs for your retrogaming and computing:

 

theoretically the best hardware level emulation

 

requires some work getting setup, as far as finding the files you need and organizing them- usually more particular than software emulation

 

file types are specific and your file archive may not match the format your FPGA core wants; I've had to rename my Atari 2600 .bins to .a26 (annoying)

 

cores may be underdeveloped and missing major features (support for various file types, read/write to images)

 

most software emulation is quite advanced and undergoing active development- cores may be abandoned by the developer and community

 

smaller user base than software emulation

 

FPGAs feel more like the original computer- no windows front end needed

 

FPGAs are small and can be added to a TV setup easily

 

Keyboard (and console switch) compatibility is limited and frustrating because of special keys on vintage computers; figuring these out has been more difficult than I'd hope since there isn't a central repository with all of that information

 

FPGAs power on and operate at the same clock speed as original computers, if they are programmed to be authentic

 

---------

 

After reading this thread, I've become more interested in a MISTer setup. There is too little being adapted to the MIST at this point to expect any new developments.