Biscuits In Hell on Atari 8-bit

[playsoft]

Earlier the year I contacted Dave Hughes and asked if it would be OK to do a version of Biscuits In Hell for the Atari 8-bit computers. I wanted to do something for the ABBUC user club and the game looked fun and a good fit to the Atari 8-bit hardware.

It has just been released on this quarters issue disk, ABBUC issue #144.

[media]https://youtu.be/9p1SPeNkQso[/media]

The game has two modes of play. You can play for points where you start with 5 lives, each level has a time limit, there are (useful) items you can collect and there are obstacles in your way. I borrowed from Endless Forms Most Beautiful for a lot of this. You can also play as per the original ZX Spectrum game, where you have 128 lives to fully complete 8 levels.

There is also a version for the Atari 5200 console that I am about to release on AtariAge. It is identical to the computer version except that it doesn't have the loading or credits screen.

Thanks again Dave!

Paul

[R-Tape]

It has just been released on this quarters issue disk, ABBUC issue #144.

Great work. I'm losing track of the number of ports the 'Moebius' games have.

It looks great. I see you've added touches like the spikes. I don't know anything about the Atari 8 bit — was this an easy job for it? There are a lot of sprites there. On the speccy for example, the 'attribute snake' is really easy, because you can achieve a massive sprite just by using blocks of paper, but I assume yours has to be a pixel sprite?

Any chance you give a quickstart guide to how one might play this. Which emulator, what to type to load etc...

Seeing this has cheered me up massively. Thanks a lot!

[XTM]

That version looks great with some cool effects not present in the Speccy version, like the teleportation "after-image" when you move up/down. The character reminds me of a mix of the ones in Dig Dug and Mr.Do.

[Morkin]

I don't know what it is, these ports (arcade, Atari) seem to fit these games very well.

...Can just about keep up watching the vid... That sustained de-materialize animation is indeed noticeable - probably easier to work out where the sprite is when you're controlling it yourself though..!

[playsoft]

Great work. I'm losing track of the number of ports the 'Moebius' games have.

Thank you. I didn't know about the others initially. I found an entry for Biscuits in a ZX Spectrum database which said it was a clone of Moebius GoatLizard on the Amiga. I found that and on the title screen it credits you with the original game concept. I thought the database must have had it the wrong way round until I noticed the date, it was 2013. I then went on to find Endless Forms Most Beautiful. You should be really proud that there have been all these ports.

It looks great. I see you've added touches like the spikes. I don't know anything about the Atari 8 bit — was this an easy job for it? There are a lot of sprites there. On the speccy for example, the 'attribute snake' is really easy, because you can achieve a massive sprite just by using blocks of paper, but I assume yours has to be a pixel sprite?

The game was a good fit! The Atari's sprite capabilities consist of 4 pairs of player/missiles. Each pair is single colour, the player is 8 pixels wide and the missile 2 pixels. That might not sound great but they are very tall, covering the entire height of the screen. You can make good use of that height because you can trigger display list interrupts vertically down the screen and make changes to the hardware registers in the horizontal blank.

The eight enemies which remain on their platform use players 0 & 1 with display list interrupts to change their colours and horizontal position. The enemy which traverses the platforms uses players 2 & 3. The players are in multicolour mode where overlapped pixels between the two players generate a third colour. The snake uses all 4 missiles in quad width and a mode where they all use one of the playfield colour registers instead of their respective player colours.

Everything else uses playfield graphics. It's running in a 40 column 4x8 pixel character mode with 4/5 colours. It's 2 bits per pixel but you get an extra colour because the character set is 128 characters and the screen map has 1 byte per character. When the top bit is set in the screen map, that character is displayed with any playfield colour 2 pixels replaced with playfield colour 3.

Display list interrupts are also used to change the playfield colours vertically down the screen. In the areas between platforms, the foreground colours are: white, purple, biscuit and flashing. All those colours are changed for the platforms themselves.

The most complicated aspect was probably the use of character based software sprites for Moebius, the dissolve and the bullet (although that's a simplified one). There's a lot of messing around there, replacing and updating characters.

Any chance you give a quickstart guide to how one might play this. Which emulator, what to type to load etc...

I recommend Altirra:

http://www.virtualdub.org/altirra.html

It is the most accurate Atari 8-bit emulator and has great debugging facilities, plus the author wrote his own compatible replacement OS (and BASIC) so you don't have to go looking elsewhere for the OS ROMs.

You can launch it by running the Altirra or Altirra64 exe. The simplest way to load is to press Alt + B (or FILE -> Boot Image) and select the file I send you. I think by default the joystick will map to the keyboard cursor keys and right ctrl for fire. The Atari START, SELECT and OPTION keys map to F2, F3 and F4. Alt + Enter will toggle between full screen and window mode.

Currently the game has appeared on the issue disk of the latest club magazine which has just been sent out. It is also available from the members section of the ABBUC website. I wrote the game for the club since I've been a member for quite a while and never contributed anything. I like the idea of it being exclusive to club members for now as it might encourage other people to join, then for it to be released on their public downloads section when the next issue of the magazine is out. The club does a lot for the Atari community, holding yearly programming and hardware competitions with generous prizes that have helped keep the system alive. How does that sound?

Seeing this has cheered me up massively. Thanks a lot!

it was great fun to work on, thanks for letting me do a port!