Wednesday 17 May 2017

No Vectrex port this time 'round.

Well, that'll teach me - again - not to get too far into a project without checking all the details for intended porting projects! Turns out the Vectrex isn't going to have enough RAM for this port, even in 1 player mode. Wondering if it's possible to design a cart with some SRAM - the connector does have a RW# signal... oh well, it was never the primary target anyway...

As I mentioned, reverse-engineering is getting to the nasty stuff (nitty gritty) and I'm considering commencing the actual porting. My targets now include Coco3 (6809) and Apple IIGS (6502/65816), so I now need to decide which avenue to take. Would be nice to have the IIGS version at least running - if not finished - for the next WOzFest, but given my limited time recently it's a tall order!

4 comments:

  1. It seems that Vectrex carts with RAM do exist:
    https://github.com/alexkazik/mucarex/blob/master/Docs/Developer/PAGE.md

    http://www.madtronix.com/en/news/items/spraypaint-everywhere.html
    http://www.madtronix.com/en/news/items/bakfull.html

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  2. Interesting - thanks!

    I like the Alex Krazik version because it's well documented and has some nice source code that will come in very handy for writing Vectrex code... however it doesn't appear to be a product and presumably hasn't been adopted as any sort of standard...

    OTOH the madtronix website is just terrible; cryptic and just a long list of random postings. I can't even work out which device (if any) from the 'shop' has ROM/RAM???

    Not sure what to do from here-on in. I could adopt the former memory map and patch MAME to support it... and continue on from there. It would make porting a little easier than other platforms... but then again I might concentrate on IIGS first anyway?!? All assuming I get enough time... :(

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    Replies
    1. Yes, it is a bit hard to follow! There seems to be versions with 8K RAM and others with 32K RAM, but I'm not sure which is which and it's not clear what the memory map is.

      I'd adopt the earlier memory map and hope that minor changes to the source code will fix it, should you need to adopt another memory layout later.

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    2. I get the impression that the carts are all meant more for being multi-carts than dev carts... hence the lack of information?!?

      But you make a good point. Switching memory maps should be trivial should the need arise... perhaps I will consider a Vectrex port first...

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