PACE: A colecoVision core for the MiST fpga

colecoVison video game system

I decided to finish the pacedev colecovison port for the MiST. I used the platform to update the mist related pacedev files and stick the data io and osd into the framework. I wanted to use variables for the data_io ram file but mixing verilog with vhdl isn’t that easy so I used hardcoded values for now. Hopefully I can clean that up a little in the future. For now it works fine. The osd is a little wide but my clock divider can only half the frequency of the used video clock of 21.333 MHz. Enough talk just let the pictures speak for themselves:

Pitfall II on colecovison for the MiST

Zaxxon on colecovison for the MiST

From the readme:

Source files: https://github.com/wsoltys/pacedev/tree/master/sw/synth/platform/colecovision/mist
Original Source: https://svn.pacedev.net/repos/pace/sw/synth/platform/colecovision/

Update 08.07.2014:
Updated the readme with the missing keys and uploaded a new core which fixed the missing keys 5-0.

A colecovision port for the MiST?

During some free time I ported the pacedev colecovision port to the MiST. I didn’t spend much time on it yet since I dunno if its worth. It seems that the colecovision didn’t got much attention in the past and thus not many games are available for it (and no scene demos).
Anyway here are the first impressions from a colecovision running on the MiST.

Colecovision on MiST running Donkey Kong
Colecovision on MiST running Donkey Kong

Sourcecode: https://github.com/wsoltys/pacedev/tree/master/sw/synth/platform/colecovision/mist

MA2601: Atari VCS 2600 for the MiST fpga

Finally the core is ready for prime. From the readme:

Sourcecode: https://github.com/wsoltys/tca2601
Binary: https://code.google.com/p/mist-board/source/browse/trunk/bin/cores/a2600

MA2601: Atari VCS 2600 for the MiST fpga … almost

Source: http://upload.wikimedia.org/wikipedia/commons/b/b9/Atari-2600-Wood-4Sw-Set.jpg

During my search for easy portable hdl sources for the MiST I recently stumbled upon the TCA2601 which is based on the Papilio Arcade port of the A2601 done by Retromaster. Since the Turbo Chameleon 64 and the MiST are similar devices I thought of giving it a try.
The port was more or less assigning the right pins and using the input methods for the MiST. The first launch already was a success because I saw Pitfall on the screen 🙂

Pitfall with wrong colors and osd test

Unfortunately the game didn’t looked like the screen shots found in the web. It had less colors and looked more like a dark yellow/white composition. I couldn’t find the reason and contacted Till about it and after a short time he found out that the Atari VCS had some external switches one of them for B/W or Color mode … dooh! 🙂
He found some other smaller issues which I committed to the repository as well.
Pitfall and other 2k/4k games were playable but had to be compiled into the core.

A2601 running Pitfall

California Games intro

California Games

The next step will be to implement a OSD to choose the games from the sd card and upload it to the fpga. Till is cooking something together already and hopefully we have an usable Atari 2600 port soon with some limitations:

  1. Bank switching: The originial source had the bank switching schemes of the games on flash hardcoded into the source. That won’t work when we want to choose dynamicly games from sd card. So the first step will be to decide the bss depending on the size of the catridge. This will only support the Atari bank switching schemes for now.
  2. The current cpu doesn’t support the so called illegal opcodes.

The source code can be found here: https://github.com/wsoltys/tca2601
The binaries will be here: http://code.google.com/p/mist-board/source/browse/trunk/bin/cores/a2600