Space Assailants 2121 - New Atari 8bit and 5200 Game Release by Anschuetz/Weisgerber/Anschuetz

[rra]

SPACE ASSAILANTS 2121

Anschuetz/Weisgerber/Anschuetz

 

Atari 8-bit Version:

Space Assailants 2121.XEX

 

Atari 5200 Version:

Space Assailants 2121.ROM

 

Space Assailants 2121 is another new Atari 8-bit and 5200 game release by the team of Anschuetz/Weisgerber/Anschuetz.   This is the 8th game we have released this year, following Sokoban 2021, Night Rescue 1941, Overflow 2021, Kooky Diver 2021, Alien Assault 2121, Piracy 1621, and Piracy 1981.  All of these games are assembly language updates to games that we wrote in BASIC in the 1980's.  By the end of the year, we plan on finishing 14 games.

 

Instructions aren't really necessary for this game.  Everybody knows how to play Space Invaders.  The only real difference is that you must avoid all of the scrolling stars instead of dodging missiles shot by aliens.  Also, there are no shields to protect you.

 

Space Assailants 2121 makes use of the same exact Antic 4 character set bitmaps that we originally came up with in the 1980’s.   Each space assailant is 2 characters wide.  The original BASIC Space Assailants game (available on Atarimania.com) was not only fun to play, but it was also a technical demonstration of using BASIC to control two separate display lists flipping back and forth.  The original BASIC game used Antic character mode 4 for the space assailant characters, and used BASIC graphics mode 4 for the scrolling stars.  The two displays alternated each frame, so there was a flickering effect like the Atari 2600 Pac-Man ghosts, but it demonstrated that you could display two completely different graphics modes simultaneously.   We submitted the game for publication to Compute!, Antic, and A.N.A.L.O.G. magazines, but none of them accepted the game, citing the flickering display and "too many Space Invaders clones" as reasons.  I have attached the letters below.

 

For the Space Assailants 2121 Assembly update, instead of using BASIC graphics mode 4, a single player is used for the entire star effect.  The horizontal player position of the star changes every row of Antic mode 4, while the vertical movement scrolls through the player bitmap.  So the overall effect shows about 20 stars on the screen smoothly scrolling down toward the player.

 

A few changes to the original game were made to improve the gameplay.  The placement of the rows in pairs of invaders was made to make it more like the original Space Invaders.  Also, in the BASIC version, the game started with only one row of invaders, and each level added another row.  In the Assembly version, the game starts with a full set of invaders.  A moving UFO was also added to the top of the screen that appears three times per level going in different directions, just like the original space invaders.  A row of mountains was added at the bottom of the screen, so the ship moves on terra firma instead of floating in space.

 

We hope you enjoy the game.  Let us know in the comments!

 

Robert Anschuetz

Eric Anschuetz

John Weisgerber

 

 

[Rybags]

Pretty good.  Do you still have the one you submitted in the day?

Obviously if it was in Basic it would have been lacking compared to this release but it'd be interesting to know what they rejected.

[rra]

18 minutes ago, Rybags said:

Pretty good.  Do you still have the one you submitted in the day?

Obviously if it was in Basic it would have been lacking compared to this release but it'd be interesting to know what they rejected.

The original BASIC versions of all of our 14 games written in the 1980's are on Atarimania.com.   Of those 14 games, 2 were bought but never published by Compute (Kooky Klimber and Night Rescue) and 3 were bought and published in Antic (Kooky's Quest, Overflow, and Robot Dungeon).   We also submitted several of the other BASIC games to the three big Atari magazines but weren't bought or published.

 

Here is a link to the BASIC version of Space Assailants.

Atari 400 800 XL XE Space Assailants : scans, dump, download, screenshots, ads, videos, catalog, instructions, roms (atarimania.com)

[Rybags]

Thanks - it seemed to have a bit of a problem working in Altirra - I had to fiddle around to get the joystick input going even though the fire button was fine.

Yeah - a bit lacking.  But in those days we had a bare fraction of the resources and knowledge going around now.

[Mclaneinc]

No probs with j/s here in Altirra, just set to XBOX360 mode using a PS4 pad..

 

Game would have been a decent one back then, not so much now BUT still great to have...Thanks guys..

[TrekMD]

Very cool.  Thank you!

[youxia]

Thanks for the game, but also for posting these letters. That's a great glimpse into the part of the scene I knew little about. Especially the handwritten "we have enough space shoot'em ups to hold us up for two years!" bit...shows you how wildly popular and educational this hobby was.

[+sramirez2008]

1 hour ago, youxia said:

Thanks for the game, but also for posting these letters. That's a great glimpse into the part of the scene I knew little about. Especially the handwritten "we have enough space shoot'em ups to hold us up for two years!" bit...shows you how wildly popular and educational this hobby was.

Couldn't agree more...thanks for including the letters and of course, for the wonderful games (especially the 5200 translations).?

[rra]

Here are a few additional scans of correspondence with the Atari magazines during the games submission process in 1984.  It is hard to imagine that the correspondence back and forth took weeks and months.  There was no email back then, so everything involved sending a letter and waiting for a response in the mail.

 

Antic Evaluation Letter below sent to authors while they were reviewing material for submission...

 

 

COMPUTE's letter below informing us that the cassette didn't load!  We developed most of our games using a shared Atari 400 with a 410 cassette recorder.  A lot of time was wasted when the program that we thought we saved the night before wouldn't load the next day when we resumed programming.  We lost an entire game to a dead tape that was based on Atari's Night Driver.

When a game was rejected, COMPUTE sent us an Author's Guide that would give us game programmers tips on how to improve their games to get them accepted in the future.   For us in the 1980's, when one magazine rejected a game, we would send it to the next magazine, etc.   If all three main Atari magazines rejected a game, we would just leave it alone (for 30+ years) and move onto another game.

[+sramirez2008]

1 hour ago, rra said:

Here are a few additional scans of correspondence with the Atari magazines during the games submission process in 1984.  It is hard to imagine that the correspondence back and forth took weeks and months.  There was no email back then, so everything involved sending a letter and waiting for a response in the mail.

 

Antic Evaluation Letter below sent to authors while they were reviewing material for submission...

 

 

COMPUTE's letter below informing us that the cassette didn't load!  We developed most of our games using a shared Atari 400 with a 410 cassette recorder.  A lot of time was wasted when the program that we thought we saved the night before wouldn't load the next day when we resumed programming.  We lost an entire game to a dead tape that was based on Atari's Night Driver.

When a game was rejected, COMPUTE sent us an Author's Guide that would give us game programmers tips on how to improve their games to get them accepted in the future.   For us in the 1980's, when one magazine rejected a game, we would send it to the next magazine, etc.   If all three main Atari magazines rejected a game, we would just leave it alone (for 30+ years) and move onto another game.

Wow. This would make for a cool CIB version.  Thanks again for sharing.

[rra]

What is CIB?

[darwinmac]

2 hours ago, rra said:

What is CIB?

I believe it stands for “complete in box”. If you were to create a boxed version, he was suggesting copies of the letters could be included as extras. 
 

Bob C

[+sramirez2008]

49 minutes ago, darwinmac said:

I believe it stands for “complete in box”. If you were to create a boxed version, he was suggesting copies of the letters could be included as extras. 
 

Bob C

Exactly.  Apologies, I should have written out complete in box vs CIB.

[+bhall408]

Alot of fun, and a great update on the 80s version!

 

My high score so far is 6750...

 

Taking requests?

 

Would love some additional effects -- explosion for when you or saucer get hit, and some sort of game over for a few seconds before returning to the title screen. 

 

For game play, I could imagine it being cool if your shots took out the falling debris same as the assailants (but 0 points?)

 

And riffing on that theme, I could totally see a mash up of this game with Astrosmash -- the invaders attacking, the debris falling, and then some assailants or ships or missiles/bombs dropping too. Then it would invaders meets galaxian meets astrosmash, the 2122 version! 

 

Since this is a shoot and scoot, we'll have Argon default to the 4-way digital stick for better accuracy.

 

(We're working on a special 2-way digital for shoot and scoots later on)

 

[+sramirez2008]

Wow.  Lots of fun!  Played several games this morning and made it to level 8.  That space ship really zooms across the screen on that level.  Thanks again for translating the game to the 5200.

 

[rra]

@sramirez thanks for posting pictures of Space Assailants playing on your actual 5200 console.  We should have added another digit to the score!

[+bhall408]

1 minute ago, rra said:

@sramirez thanks for posting pictures of Space Assailants playing on your actual 5200 console.  We should have added another digit to the score!

Are you using 2 bytes BCD internally and adding a 0 for display?

 

[rra]

No BCD.  Each digit is a separate variable and we have a routine to add to digits and handle the carry to the next digit.  Then copy each digit to the screen by adding 32 to get the Atascii value.  Not the most efficient, but it works.

[+bhall408]

Just now, rra said:

No BCD.  Each digit is a separate variable and we have a routine to add to digits and handle the carry to the next digit.  Then copy each digit to the screen by adding 32 to get the Atascii value.  Not the most efficient, but it works.

Interesting! Do you still tack on the 0 then? I always thought that was a good hack when your scores were multiples of 10 anyways.

 

For 2 byte BCD you get to use the ADC opcode. The extra work is in splitting out the 2 nybbles for display (AND and ROR depending).

[eea]

Yes, the zero is just tacked on and is always just displayed at that screen location. Makes it easier to have bigger scores and tracking less score digits.

[+bhall408]

Two gameplay videos have shown up over the weekend on YouTube...

 

ATARI 8 BITS FOR EVER:

 

and AtariTeca:

 

[+bhall408]

On 9/17/2021 at 5:53 PM, bhall408 said:

(We're working on a special 2-way digital for shoot and scoots later on)

The 2-way digital stick for "shoot and scoot" games has been implemented in Argon, and will show up in the next public beta later this week...