conversions and other stuff

[dr. kwack]

I lately rediscovered in my collection of classic computer stuff two books: Marvel Book of Computer Fun volumes one and two. It's a bunch of simple BASIC programs written around Marvel Comics Characters.

 

I'd like to do them on my Atari 8 bit, but it has no listing! What other popular computers of the time are closest to Atari Basic? I'm guessing C64. How hard would a conversion be?

 

Also, this will be my first summer off for a few years (I'm a teacher). One item on my to do list is to write a text adventure using AdventureWriter. I'm thinking of doing a Questprobe game featuring... Howard the Duck. Seriously. Never used the program before, any suggestions or advice?

[kenjennings]

I lately rediscovered in my collection of classic computer stuff two books: Marvel Book of Computer Fun volumes one and two. It's a bunch of simple BASIC programs written around Marvel Comics Characters.

 

I'd like to do them on my Atari 8 bit, but it has no listing! What other popular computers of the time are closest to Atari Basic? I'm guessing C64. How hard would a conversion be?

 

"hard" is relative.

 

If the game includes graphics for a different computer, then "hard" could be hard.

 

If not, then BASIC is BASIC (mostly). Strings are the biggest difference for Atari BASIC. Most other things are easier to adapt. If you can identify the platform used for the BASIC listing, then you should be able to google for a reference guide to explain how the commands work.

[Defender II]

I lately rediscovered in my collection of classic computer stuff two books: Marvel Book of Computer Fun volumes one and two. It's a bunch of simple BASIC programs written around Marvel Comics Characters.

 

I'd like to do them on my Atari 8 bit, but it has no listing! What other popular computers of the time are closest to Atari Basic? I'm guessing C64. How hard would a conversion be?

 

Also, this will be my first summer off for a few years (I'm a teacher). One item on my to do list is to write a text adventure using AdventureWriter. I'm thinking of doing a Questprobe game featuring... Howard the Duck. Seriously. Never used the program before, any suggestions or advice?

 

You shouldn't have too much trouble with the text adventure. No graphics problems like mentioned above.

Have you done any BASIC programming?

[sack-c0s]

the problem with c64 basic is that it's crap. PEEK, POKE and SYS are about the only decent commands it has so consequently and half-decent 'BASIC' typein will end up just being a loop to poke a machine code program into memory and call that instead.

 

so if a C64 program uses 'purely BASIC' then it'll be trivial to port to the Atari, but a bit rubbish. If it uses assembly then at best it's going to be a heavy rewrite of the 6502 it dumps into memory, at worst a total rewrite.

 

BBC basic is also a problem because it's probably the best BASIC, or to look at it another way the best damn macro assembler you'll ever use - you can put 6502 between square brackets and use the BASIC to control assembly to create macros, fill out lookup tables, etc. So a lot of it could end up being 6502 and not BASIC. On the plus side though it's a pretty barebones 'framebuffer strapped to a CPU' type machine and you do have the 6502 source to look at.

 

The ZX Spectrum basic is a bit of a pig to code in (it's like keyboard twister - left finger SYMBOL SHIFT, right thumb J, etc.) but maybe reading the code it should be fairly generic and one of the less painful machine to port from. Being a very popular machine in the UK there should be a lot of listings around for it too.

 

But whichever machine you go for it's going to be an effort

[deathtrappomegranate]

Is this one of the books?

 

http://www.flickr.com/photos/paxtonholley/sets/72157627268305495/with/6024978513/

 

If so, it's not very complicated stuff. The strings would probably be the trickiest part to convert, but there's nothing too daunting otherwise.

[miker]

Ok, guys. Here's my trial.

 

I've retyped Bombs Away from the link given by deathtrappomegranate,

 

Steering by hitting L R U D (respectively).

 

Have fun!

BOMBS.BAS

[dr. kwack]

That's the book! Very cool miker. This will be a perfect time killer for the summer.

[devwebcl]

Ok, guys. Here's my trial.

 

I've retyped Bombs Away from the link given by deathtrappomegranate,

 

Steering by hitting L R U D (respectively).

 

Have fun!

 

nice work, however I didn't understand the game... (I love conversions )

[miker]

Well, the plot is fairly simple. There are bombs appearing around our "superhero" and you have to press the right direction (Left, Right, Up or Down) to hit the bomb and make it go "away". That's all.

[+Stephen]

Sounds like the 1st "stage" in Cosmic Ark, one of my fave 2600 games.

[miker]

Ok, next one. Program looks trivial, but originally usues string instructions, which are not available in Atari BASIC, like LEFT$, RIGHT$ and MID$.

 

But... you can do without them as well.

 

How?

 

- Instead of LEFT$(A$,X) use A$(1,X).

 

- Instead of RIGHT$(A$,X) use A$(LEN(A$)-X,LEN(A$)).

 

- Instead of MID$(A$,X,Y) use A$(X,X+Y).

 

Of course the above instructions should be TRAPped, to avoid goig out range error.

 

OK, back to the program... Type in your name (12 chars maximum, or else it will be cut), and watch you name turning into... Hehe, no more hints. Just run it!

 

SPACE restarts the effect, any other key ends the program.

NAMESTAR.BAS

Edited April 25, 2012 by miker

[NuY]

- Instead of RIGHT$(A$,X) use A$(LEN(A$)-X,LEN(A$)).

 

- Instead of MID$(A$,X,Y) use A$(X,X+Y).

 

Slight correction - RIGHT$(A$,X) returns the last X characters of a string, so if one had a string of "1234567890", RIGHT$("1234567890",3) would return "890". In your example, this would come out as A$(LEN(A$)-3,LEN(A$)), which evaluates as A$(7,10), which returns the last four characters.

 

So, to get the equivalent, you need to add 1 to X in RIGHT$, hence:

 

RIGHTS$(A$,X) becomes A$(LEN(A$)-(X+1),LEN(A$))

 

Similar for MID$ - MID$("1234567890",5,3) would return "567", which would need to be in Atari Basic as A$(5,7). Hence:

 

MID$(A$,X,Y) becomes A$(X,X+(Y-1))

 

This should be correct for standard Atari Basic and Turbo, not sure about Basic XL/XE or any others.