Re: More thoughts about Lode Runner & other multiload games...

[Steve Nickolas <usotsuki@buric.co>]

Thinking again.

1 - LR again

I still have some notes gathered from reverse engineering the game, but 
none of this points to those three functions yet. :(

It does mention where some code can be cut out to disable the Editor, 
something which I will be doing.  Mostly that's 7B84-7C4C which is 201 
bytes.  Something could probably be stuffed in that space.

A possible hint is in these notes: "61E4 = high score table routine",
"6056 = play a level", "786B = show score list".

If a full dasm is done it may be possible to put the three demo levels 
lower in memory, which are stored at 9F00-A1FF.  (It may be that the 
bootloader, still present from 0800-0CFF, is not needed for anything and 
can be reappropriated.)  My notes suggest only 3 other pages, 9B-9D, are 
used between 9000 and 9EFF, which could perhaps also be moved, allowing 
the entire code to sit below 9600.  (Thus allowing a 2-stage DOS loader 
for test purposes.)

With relocation, it is safe to reserve 9800-BFFF for 10K worth of extra 
levels on top of the entire language card.  I offered 24K as an ideal 
before, but this would allow 26, and possibly up to 28 (9000+).  If level 
compression is utilized, it might be possible to stuff all 150 levels in 
there and on the language card.

--

2 - Donkey Kong

If it is, as some think, possible to compress level data by at least 50%, 
it may be possible to stuff it all on the language card; but I hesitate to 
attempt to reverse-engineer the code since not the whole engine may be in 
memory at once.  (With LR, I know it is.)

I feel like all this should be possible and yet have no clue how to do it. 
Somehow I just don't understand anything involving the disk. :<

I need a guru. x.x

-uso.