Friday, 26 May 2017

Variables disclosed as I reconsider the Vectrex

After some discussion with jmk (which can be seen in the comments of the previous post) I'm now reconsidering a Vectrex port. Given there exist a few multi-carts with RAM expansions, I think there's still enough of an audience to make the port worthwhile, especially considering I'll have a 6809 core for the Coco3 - even if it is just a 'proof of concept' playable demo.

That decision aside, just as I was getting bogged down trying to determine the usage of the player data RAM blocks, I notice that much of the work has (recently?) been done for me on a well-known reverse-engineering website. It really is getting to the point where I should reveal the project...

But for now, I'll take this new information and persist with the reverse-engineering whilst the code is relatively self-explanatory. If and when I do hit another brick wall, I'll turn my hand to starting one or more of the ports. I have a deadline for the IIGS port at least...

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!

Monday, 15 May 2017

Slow going, time to start porting?

Slowly, slowly chipping away at the code; not that I've had much time to spend on it lately, but it's also slow going as all the low-hanging fruit has been... commented!

I'm starting to think that it's time to start on the port, and perhaps work in parallel with the rest of the reverse-engineering. This approach worked reasonably well with Knight Lore, and I've certainly got all the hardware figured out to a point to allow me to do so.

If so, then I'll start with the 6809 port - but not for the Coco3!