New Release: Doom

Witzo · Post by **Witzo** » Fri Jan 18, 2013 1:00 pm

Kweepa, your project has been noticed by the Google+ MOS6502 group:

https://plus.google.com/108984290462000 ... EkEhCrKr6q

Apparently, a Doom-on-C64 project never came to any demonstrable results, while yours sure does!

Kweepa · Post by **Kweepa** » Fri Jan 18, 2013 4:03 pm

Thanks for pointing that out!

orion70 · Post by **orion70** » Sat Jan 19, 2013 5:21 am

Commodore 64 0 - VIC20 1

From the comments:

Denial is a dangerous one. Very active, very VIC.

Kweepa · Post by **Kweepa** » Mon Jan 21, 2013 3:43 pm

New version:
Fixed flashing projectile bug.
Maybe fixed lockup in checkSectorForPickups.
Updated credits.
Fixed finish game and restart not clearing inventory.
Cleared screen for "ENTERING" message.

The flashing projectile bug was due to a bug in cc65. (long)/(unsigned int) produces an unsigned result. I reported it to Ullrich, and he's on it.

It's embarrassing to be using such things (long divides), but it's only for the projectile launch frame.

The lockup looked like a C stack overwrite. I'm not sure, but I freed up a few bytes and haven't seen it since.

tokra · Post by **tokra** » Mon Jan 21, 2013 4:53 pm

Hooray! Did not notice the hang-bug again (yet?) - played for about 20 minutes. Will test some more in the next few days. Hopefully the bug is squashed.

The "reverse-ostrich" is still possible I see - if it's by design let's call it a technique for expert-players

Noticed there is still the pe1m9-file on the .d64 - maybe you still feel like adding a secret level

?

Kweepa · Post by **Kweepa** » Mon Jan 21, 2013 5:25 pm

Awesome. Thanks for checking.

E1M9 is a test level that I was using to track down bugs. I don't think I'm going to push my luck trying to squeeze more hacky code into this game for the secret level. Next week I'll probably change my mind

I'll leave the file there to tease the curious.

The "reverse-ostrich" isn't "designed", but it's totally expected and I use it all the time to squeeze past enemies that are in the way. Enemies only block the player from moving forward, and only if there's an enemy within 2 map units of the player in in the center of the screen.

tokra · Post by **tokra** » Thu Jan 24, 2013 2:38 pm

Ok, real VIC testing today. Played through on my PAL-VIC with MegaCart and noticed a few things:

- you can press runstop/restore to kill the game (NMI-vector at $318/319)
- you can press c=/shift to destroy the graphics (Deja Vu)

- when I run out of ammo original Doom reverts to the next (lower) weapon automatically. It happened to me once or twice - since you cannot see the weapon action it "feels" like a bug if it does not revert
- Bug or feature? In "Command Control" in the top left corner is an ammo that does not disappear but instead keeps on giving you ammo.

- would be nice to have and "Quit Game" option in the Main Menu that gives snide remarks like the original
- I was missing a "Pause"-feature until I noticed I could just go to automap-mode for that

I also tested this on my NTSC-VIC with MegaCart - works like a charm
Also tried my "Final Expansion 3" - works great on PAL. But on NTSC and Final Expansion I get all sorts of screw-ups. Mostly the game does not start at all. Once I got to the menu, could move through it but not make a choice (like the "Return"-key was broken). Very strange indeed, since all other combinations work:

PAL + Mega-Cart -> fine
NTSC + Mega-Cart -> fine
PAL + Final Expansion 3 -> fine
NTSC + Final Expansion 3-> broken

NTSC + Final Expansion seems to be a rare combination, but it *should* work and I cannot understand why it does not. I could understand if maybe Doom breaks some memory locations the FE3 uses from RAM-swapping, but then this should break PAL as well. Maybe Diddl has some insight since he designed the FE3?

Anyway, the game plays a little smoother on PAL, no wonder since the PAL-VIC is about 8% faster than the NTSC-version. Mike may be able to explain why that is, I forgot

Mike · Post by **Mike** » Thu Jan 24, 2013 2:54 pm

tokra wrote:NTSC + Final Expansion 3 -> broken

Could it be the Easy Wedge was active by chance with this combination? In that case, the memory between $0400 and $0FFF is write-protected by FE3, and Doom can't use it anymore. I'd try the combination I/O Register on (R, x), Easy Wedge off (W, .) and All RAM (F7) in the RAM Manager menu.

tokra · Post by **tokra** » Thu Jan 24, 2013 3:17 pm

Nope, I always deactivated Wedge and I/O-registers and this works fine in PAL. I just tried the combination you suggested. Same results as before. Doom on NTSC won't work with FE3.

Kweepa · Post by **Kweepa** » Thu Jan 24, 2013 4:34 pm

Hum.
I'll have to fix those bugs, tokra.
I should also revert to the earlier weapon when out of ammo, like you say. Forgot about that.
Thanks!

I have no idea what's happening with the final expansion. I can only imagine that there are protected memory locations, but then that would break a lot of games.

tokra · Post by **tokra** » Thu Jan 24, 2013 6:47 pm

Seems to be a Final Expansion-issue: Writes to $2400 - $2fff influence $0400 - $0fff. It is not the same value that is written, but 2 out of 3 times the original value in $0400 is destroyed when I write t $2400. It does not happen the other way around (i.e. writes to $0400 do NOT influence $2400). Very strange, even moreso since it ONLY happens with NTSC and the same machine works with the MegaCart and the same FE3 works on a PAL-machine.

Kweepa · Post by **Kweepa** » Thu Jan 24, 2013 7:02 pm

Sounds like some kind of timing bug with the bank mapping in the FE?
The timing would be slightly different with a different clock speed. Although it's strange that the faster machine works.

darkatx · Post by **darkatx** » Thu Jan 24, 2013 8:18 pm

I ported it over to the real machine too and it won't run.

Unless I'm doing something wrong trying to load it up

I'm using NTSC and Eslapion's 32K expansion unit. Tried it out with Realms of Quest III to make sure it works and it loaded it just fine.
I used Star Commander to port it over with.

Kweepa · Post by **Kweepa** » Thu Jan 24, 2013 11:08 pm

32k isn't enough!
You need an expansion that fills the 3k in block 0 and the 8k blocks 1,2,3,5.
I think the only new expanders that will work are the MegaCart and the Final Expansion.
Sorry

[EDIT] Nothing to see here.

Vic20-Ian · Post by **Vic20-Ian** » Fri Jan 25, 2013 12:23 am

Kweepa wrote:32k isn't enough!
You need an expansion that fills the 3k in block 0 and the 8k blocks 1,2,3,5.
I think the only new expanders that will work are the MegaCart and the Final Expansion.
Sorry

[EDIT] Nothing to see here.

Is this the first case of a Vic20 getting bloatware

Only kidding - amazing to see the Vic with only memory expansion being pushed so far.

For your next project may I suggest porting N64 Goldeneye ?

With an FE3 you do have another 512KB to play with.