WIP: Reversi

[carlsson]

A friend of mine developed a soft sprite routine for the VDP a while ago, albeit for Z80. I might bug him about converting it to 6502. Frankly I don't know which end is more difficult: the choice of CPU or the choice of graphics hardware.

[Mobsie]

Hi Carlsson,

i forget to say that your Reversi is great!

I will find a way to run the Homebrew Software on a real CreatiVison.
I have the Multicart for the ColecoVison and is great.

But i think the fan base is to small for someone to invest in a project like this.

[carlsson]

We'll see. Perhaps we can fit eight 4K games within 32K EPROM, of which each set of two games is selectable with DIP switches and then the user on power on selects which of the two games to play. As it currently stands without music, Reversi is < 3K IIRC. It can be checked by increasing ORG until a point where the assembler complains about address mismatch.

I'm quite sure MADrigal eventually would be able to sell all copies of a limited run homebrew software, estimated next year. Of course if someone like Scouter3d comes up with an ingenious SD card interface it would be even easier to load whichever homebrew will emerge. I've read on the AtariAge forum about people interested in developing for the Creativision/Wizzard so with the right promotion and some of us pioneering we might get a bit of development going on.

[carlsson]

"Appendix E" of the "Programming guide" to the TMS9918.

I located the guy on AtariAge who scanned the book and sent him a PM asking if he'll scan the rest of the pages.

[MADrigal]

> Perhaps we can fit eight 4K games within 32K EPROM, of
> which each set of two games is selectable with DIP switches

Why DIP switches? 32K can be addressed from the CPU all in a row, no need to bank switch. You need a 8-games menu, and you don't even need to do eight 4K games, you can even mix games of various sizes, making sure the total doesn't exceed 32K. You can even recycle routines, text, graphics, music, etc

> I'm quite sure MADrigal eventually would be able to sell all
> copies of a limited run homebrew software, estimated next year.

I'm ready.


> Of course if someone like Scouter3d comes up with an ingenious
> SD card interface it would be even easier to load whichever
> homebrew will emerge.

That's for sure!!


> I've read on the AtariAge forum about people interested in developing
> for the Creativision/Wizzard so with the right promotion and some of
> us pioneering we might get a bit of development going on.

I know a few people willing to code games for the CreatiVision, but they're currently busy in other projects. They need to see some well-done routines (Carlsson, this is for you to start.

[carlsson]

Aha, I thought the circuit boards you already got were designed to push 8K at a time, but if one can install a 32K EPROM and have it all mapped into memory, even better. It would require a cold start to get you to the menu, the reset button to restart current game and perhaps holding down a number key on the keyboard to get a quick start to desired game. Very nice!

Whenever I get the chance, I'll break out the utility routines into separate code + brief documentation. I feel this thread for example has deranged a bit so it'll be for everyone's good to keep WIP and general development separate.

[MADrigal]

By the way, I still prefer getting 1 single game per cartridge.

[carlsson]

I just think it is a waste of material to produce board, shell, box etc for a game less than 4K code. Of course whenever development takes full scale, we might see 16K games that indeed deserve an individual release instead of packed as a compilation.

[MADrigal]

> I just think it is a waste of material to produce board, shell, box etc for a
> game less than 4K code.

Well, there's plenty of games for the CreatiVision, which fit into 4K
Crazy Chicky... Air-Sea Attack... Sonic Invader...

I know it's a "waste", but I think as a "collector". Single games are much cooler than compilations. And I prefer having "a complete collection of 4 game carts by Zapac Software" than "the cart with all games by Zapac"

I remember the series of 4 game carts made for the Intellivision are now worth a fortune. They were extremely simple games like Tetris or similar puzzles. They sell for hundreds of dollars - if you're lucky finding them on Ebay!

My 2 cents

[carlsson]

So if I'd be itching to program my own 32K EPROM to replace the one in my DiagnostiCart, is there anything in particular I need to know? That one has DIP switches for sure, even if future carts don't have to have them. Hm, 32K equals 27256. I need to see if I've got some of those. Would a 27128 work for only 16K?