Thursday, 10 October 2019

RetroChallenge 2019/10 Coco Version Akalabeth on the Rocks?

On to a new project?
The amount of memory reported by MCX Basic running on the emulator is 28703.  I think you get even more memory on real hardware. And you don't have to clear memory for use by hires commands.  It's just reserved automatically. The amount of memory reported by Coco Basic if I PCLEAR 2 (2 X 1.5 memory pages), which is needed for the PMODE2 screen leaves only 25889 bytes.  I'm starting to fear that the program won't fit on the Coco.

I have only a few hundred bytes free after all the array variables and other variables are declared in the MCX version.  In the Coco version I will also have to insert spaces in all the following instances of variable names touching directly on Basic command keywords:
ON T_GOSUB
FORT=D_TO10
IF A>D_THEN
IF P_ANDP_OR
B_STEP
The MC-10's Basic is fixed to be able to search in a way that it can differentiate between variable names and Basic keywords.  This means you don't need to put any spaces between commands and variables, which is really handy for saving memory and squeezing programs into the MC-10.

I don't think 25K will be enough to run this very large program.  This will leave it to Curtis to bring the game to Coco in the form of a Basic09 program. There might be some troubles here too, as I remember that memory management, as least on level 1 Basic09 can be a little tricky.  I think the largest program I ever compiled was one that needed me to use the #32 argument when running Basic09.  Probably easier in level 2 to get all the Graphics routines loaded up.  Hope so. I'd really like to see this game ported to a windowed program running under Nitros09.

So this might be the end of my Akalabeth porting project. I've been play testing a bit, and the program seems pretty stable.  However, my son Charlie is coming home this weekend for Canadian Thanksgiving, so I'll abuse my fatherly authority and position as family cook to extort some game testing out of him.  He's always really good at sniffing out bugs and takes great relish in pushing programs into situations where conditions are generated that reveal bugs.  I think it's his way of getting some revenge for me making him do beta testing of my crappy old Basic games.

So it might be onto the next project for me. I'm thinking of taking the example program "Mazies and Crazies" for the TRS-80 and typing it in and porting it to MC-10.  I haven't found a working version available anywhere on the Net.  Just the scan of the book by Frank De Costa, "Writing Basic Adventure Programs for the TRS-80" in which it appears.  Or maybe a text adventure of some kind.  Hmmm....

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