I'm going to have to spill over onto a second picture anyways so I'll probably have different sprites depending on the tile Chip is on.  All that should change is that instead of the sprite's location in the picture being constant it'll be dependent upon the variable N, which is already in use in my program.

Thanks for showing me how to mask sprites though

Sorry, I was sure that masks only works with xor

Top: XORing the mask and sprite
Middle: AND the mask and OR the sprite
Bottom: OR the sprite on the tile (what simplethinker is doing now)

It's funny that the bottom 2 are the same. Not the case for all creatures and bg tiles though.

That screenshot (on the other page) looks pretty nice.

Chip's Challenge was actually one of my favorite games years ago (I think it came on a Windows 95 computer I used to have)

Thanks

It came on a computer I had (might have been win95) and was the first computer game I ever played.  I accidentally deleted it (never tell a 6 year old playing in DOS is fun) but I finally came across it a few weeks ago.  I figured that my difficulty with it was the fact I was 6, but even now (12 years later) some levels take a few dozen tries

Oh it's from a Microsoft software? I'M never gonna play this calc game, then.

J/k I don't mind lol I use Windows and in some rare occasions IE too. Nice job so far

I have a copy of the "Microsoft Entertainment Pack" 1-4 along with Bob's House and a few other M$ goodies. I keep them all on my flash drive in case I'm feeling nostalgic.

Well, I have some bad news (a lesson on the dangers of announcing projects too early).  Remember when I said a few posts back that there are a few levels I would have to leave out because of the insane number of enemies?  That number has now grown to over 1/2 (I'm playing the computer version and I'm at level 90 now) and I expect when I get to higher levels it will eventually reach 2/3.  The problem isn't really the number of enemies that start, but the "clone machines" make the number of enemies highly variable since they provide an unlimited number of enemies.  I was thinking I could handle 10-15 enemies at once, but looking at many of the levels it wouldn't be a stretch to assume 100+ at once is easily reached

This leaves me with three options:
1) Keep going and trying to be as close to the original as possible even though ~2/3 of the levels would be gone.
2) Keep going but don't try and model the levels after the original and create my own with little to no enemies (poorly designed levels too probably).
3) Scrap the project.  I could potentially use the engine I have so far for another puzzle-type game though.

I don't think you should stop. Since it's just a calculator it doesn't have to be exactly like the original, you can simply include less levels and less enemies at once to keep the game at decent speed. I won't mind playing the game if it has less stuff than the original, almost all calc games are like this and it will still be fun to play anyway