What is TuneLayer?

[newcoleco]

Hello!

Aswald send me a BASIC code : a video game made by himself.
I tried to convert it for the ColecoVision but I wasn't able to do exactly like the original game.

You move in a room with warp doors (like pacman). There is no walls in the room (so it's not a maze). But things appear each time you walk one step. Some things are good, some things are bad and you are the only one who can move in the room.

I have done a few screenshots of my Coleco version of TuneLayer.
http://www.geocities.com/newcoleco/tunelayer.html

[Aswald]

Not bad! Colors are different, but that's Tunelayer! The Tunelayer was yellow, and the Double Notes were red, for example.

Island of Foxes is not a really complicated piece of programming, just oddly done. Based on my descriptions, how hard would a ColecoVision port be from the Commodore 64?
By the way, I think I may have thought of a way of allowing one to continue play by use of a code that'll work on a ColecoVision. But until I get a working Commodore 64, there's no way of telling for sure.

[newcoleco]

It's difficult to answer your question because I didn't finish my "chateau du dragon" project.

The main problem will be the C compiler limit. There is a limit in hi-tech C compiler about length of file size. To avoid this problem, you will have to struct your program to avoid making a big one C file. I reach this limit with the project Ms Space Fury.

I don't think the RAM limit will be reach... But, because the coleco bios use some specific memory address, you may have a problem with memory corruption. I have this kind of problem with my Reversi project because I programmed an ALPHA-BETA algo to do the AI.

[Aswald]

Uhhh...duhhh....(brain shorts out).
Me, uh, know how to isolate blocks of memory from BASIC and how do machine language subroutines on Commodore 64...

[Aswald]

Brain reactivates...

I don't understand this?

My understanding of programming limits is rather simple: any given console or computer has a certain amount of information it can hold. In the case of the Commodore 64, the limit (if you program using BASIC) is roughly 40K RAM. Of course, you can divide up a program using disks; most RPGs did this. I guess the console equivalent is "bank switching."

It doesn't seem likely that "Island of Foxes" would fill up the ColecoVision's 32K ROM limit- the game just isn't that big or complicated. Most of it has a pre-drawn map, with "you" as a memory location moving on that map; what happens depends on what "character" on the map you move that location onto. If you move "North" (up), you subtract 32 from your current location (I've set up the C-64 version to use =/- 32 instead of 40)- if the character your location lands on is, say, #45, then you go to the subroutine that informs you that you are in a meadow, and that an Elolypa is there. All information relevant to Elolypa combat is loaded (I use PEEKs instead of variables) into the appropriate locations for the combat subroutine. Since the odds of an Elolypa hitting you are 60%, 60 is loaded into, say, memory location 30018. The computer PEEKs this location to see what the odds are (if it was an Ariskyloc, that number would be 70 instead of 60).
I did this so one combat subroutine could be used for all combat sequences.

Hopefully, sometime in the forseeable future I can get a working Commodore 64. But I hope anyone reading this isn't expecting a game that will blow Lord of the Dungeon or Wizardry out of the water; it isn't. It's just a simple, pleasant, text game. Nothing more.