My first game in assembler

[TGB1718]

16 minutes ago, manterola said:

At least for me, the main struggle with assembler is related with the implementation of "functions"

In pure assembler there are no "functions" as such, just subroutines, however with modern assemblers like MADS

functions (procedures) are available with or without passed in variables

i.e.

aproc .proc

code here...

        RTS

        .endp

or

myproc .proc (.byte var1, .word var2)

 

code here ....

           RTS

           .endp

 

Generally code in VBI is screen orientated (including PM's) where you want to complete processing while the

screen is not being drawn.

 

Your MAIN code loop can be doing anything needed outside of VBI, but it is still possible to synchronise it with the VBI by setting/clearing

handshake flags between to 2 processes.

 

DLI's by their nature are short/sharp processes and generally used to change line/screen colours on the fly or move PM's horizontally

enabling the same player to appear in a different horizontal position further down the screen, if DLI's take too long

to process, you will see some corruption on screen or undesirable effects. 

[manterola]

I totally agree with the subject of "functions", "procedures" or "reusable code" kind of theme, and there is this whole thing about passing arguments using the accumulator or using the page 0 available locations, etc. That for me is something I have read in theory, and play a bit in practice but I don't feel particularly comfortable about it yet. 

Regarding the "main loop" I have seen games that do everything in the VBI, and almost nothing except init in the main program. I think that way is a good ption with simple games, so you dont worry bout synching the different parts of your program. 

Anyway, sorry for hijacking this post, just wanted to add a bit to the conversation regarding obstacles for Assembler newbies like me, coming from basic, c, pascal, fortran, etc. traditional languages.

 

Edited August 25, 2022 by manterola

[Panther]

4 hours ago, manterola said:

...coming from basic, c, pascal, fortran, etc. traditional languages.

I'm rather certain that assembly predates those...

[Wally1]

just write one k

 

i mean 2 or 3 line programs,

till you see what they do.

 

and never give up!

 

[Wally1]

rdefabri,

 

i'm 52.  

 

you're never too old!

it sharpens one's mind.

 

one trick is to generously use comments when coding..

 

-Wally1

 

and gyros are great!

 

[rdefabri]

2 hours ago, Wally1 said:

rdefabri,

 

i'm 52.  

 

you're never too old!

it sharpens one's mind.

 

one trick is to generously use comments when coding..

 

-Wally1

 

and gyros are great!

 

I got you by a year (53) - I think with some guidance I could learn it but my head is so oriented around high level languages that assembler is a different beast for me.  I may try the baby steps but first I have to create something using BASIC, then I’ll move up.

[Jinroh]

Very great progress so far!

 

Haunted House is the fun game, and your version is looking nice so far on the A8.

[Wally1]

good luck

 

yasou

 

[Wally1]

you can wrikte a asm lang routine

[+MrFish]

13 hours ago, Wally1 said:

i'm 52.  

 

11 hours ago, rdefabri said:

I got you by a year (53)

 

I'm getting old enough now, that I'm starting to become nostalgic about nostalgia.

 

[Wally1]

how do you kill time

 

punch a cl.ock

 

[+MrFish]

13 minutes ago, Wally1 said:

how do you kill time

I used to employ a hatchet to kill time; but since the early 80's I've been using a Ginsu Knife. Those things are amazing!

 

  

13 minutes ago, Wally1 said:

punch a cl.ock

Punching a clock hurts my hand.

 

[Thelen]

On 8/23/2022 at 12:41 PM, olix said:

When I had my first Atari 400 in the early 80's, there was one game I always was jealous about VCS owners: Haunted House. I hadn't even played the game in the past, but loved the pictures on the box and the "spooky" story described in the Atari catalog. Is it really possible that there hasn't been a port of it for the Atari 8-bit computers to this day?

 

So I decided to write my own version of this game. But it's not an emulation of the original code, I'm reprogramming the game with my own code. This is actually my first machine language game ever.

That's funny, in 2002 I took exactly thesame route as you did! 🙂

 

Then, I was also wondering why there was no haunted house for the Atari 8 bit line - and was also learning assembly and did some small try out on the Atari 2600. But the system I prefered was the 800XL (the 8 bit line) what I had when I was a child. So I wanted to make a 8 bit clone - but I never finished it 🙂

Just for fun I searched my post from 20 years ago:

I really hope you finish you're haunted house and that we can have fun playing this 2600 classic!!

[olix]

3 hours ago, Thelen said:

That's funny, in 2002 I took exactly thesame route as you did! 🙂

 

Then, I was also wondering why there was no haunted house for the Atari 8 bit line - and was also learning assembly and did some small try out on the Atari 2600. But the system I prefered was the 800XL (the 8 bit line) what I had when I was a child. So I wanted to make a 8 bit clone - but I never finished it 🙂

OK. So i'm not the first one, trying to port Hauntd House. Why did you never finished the game?

 

I'm a few steps further. I see you used the PM-Collision-Detection. This was also my first try. But I didn't like the wiggling of the eyes when they touch a wall. So know i use a software based collision detection. I's a lot smoother.  Also i have since some days the diagonal movement implemented. And my firelight looks more like the original one. 

 

Next step is building the stairs and the movement to the other foors. I think this is not so difficult. After that i will install the items. And then the monsters, sound, scoreboard ..... so alot of work to do.

 

And thanks to all AtariAge users here in the forum for the good words, that's really motivating.

[Thelen]

21 hours ago, olix said:

Why did you never finished the game?

Well I don't know exectly anymore... When I was (20) years younger I started every month an new game or project and never finished something. 30 years ago I started every week a new game. (in Basic) I've made progress, now just once a year

 

21 hours ago, olix said:

I'm a few steps further. I see you used the PM-Collision-Detection. This was also my first try. But I didn't like the wiggling of the eyes when they touch a wall.

Didn't like that either, much better to do software collision!

Great job you're doing for the 1st time 6502 asm!

[+Stephen]

2 hours ago, Thelen said:

Well I don't know exectly anymore... When I was (20) years younger I started every month an new game or project and never finished something. 30 years ago I started every week a new game. (in Basic) I've made progress, now just once a year

 

Didn't like that either, much better to do software collision!

Great job you're doing for the 1st time 6502 asm!

Sounds familiar!

[olix]

Things are going on. There are a lot things to to, but i'm making progress:

 

The player can now move through all four floors of the mansion. You can collect the items and build the vase. After collecting all three parts of the vase, you can leave the house and the game starts again.

 

So, what's missing and coming in the next big step are the ghost, spieder and bat.... 

[Stefan Both]

On 8/25/2022 at 2:22 PM, MrFish said:

 

jmp	abs	0114	76	0x4c	3	3
eor	abs	0115	77	0x4d	3	4
...
...
...

I'm missing the opcode ' jwr ' ...🤭 .

 

Stefan 

[+MrFish]

49 minutes ago, Stefan Both said:

I'm missing the opcode ' jwr ' ...🤭 .

?

 

[griz]

Nice! As you can tell by my avatar, I am a big fan of Haunted House.

[Stefan Both]

On 9/22/2022 at 11:49 PM, MrFish said:

?

There must be that opcode !!!

At least, jwr must exist in my programs... 🤭

 

Jump Without Reason 😒

 

Stefan 

[+DjayBee]

6 minutes ago, Stefan Both said:

There must be that opcode !!!

At least, jwr must exist in my programs... 🤭

 

Jump Without Reason 😒

You are missing the point.

We are talking about real world computing and not of Agile Development. 😎

[+MrFish]

9 hours ago, Stefan Both said:

There must be that opcode !!!

At least, jwr must exist in my programs... 🤭

 

Jump Without Reason 😒

Ah, ok... this is all I was able to come up with (from the web).

 

Acronym    Definition
JWR    Jewish World Review
JWR    Just Within Reach
JWR    Jehovah's Witness Recovery
JWR    Johnny Walker Red (whiskey)
JWR    James Wegg Review (website)
JWR    Joint War Room
 

"Jump Without Reason"... sounds like some sort of involuntary habit (or Tourette syndrome symptom).

 

[Stefan Both]

A joke, Mr. Atari told me, years ago,  when we first met.

I could not resist 😄.

 

Stefan 

[Thelen]

On 9/22/2022 at 11:36 AM, olix said:

The player can now move through all four floors of the mansion. You can collect the items and build the vase. After collecting all three parts of the vase, you can leave the house and the game starts again.

Nice update! 🙂