Pengwin

March 9, 2012

Never mind, just found out that it is for zero-page addresses only. That will explain my error

March 9, 2012

I have this piece of code:

; Routine to load the next level
level_vec .word $0000
scrn_vec .word GameScreen + $28
outchar  .byte $00
loadlevel inc level   ;Increment the level
  lda #$05   ;If the level is now 5, then set it back to 1
  cmp level
  beq levelok
  lda #$01
  sta level
levelok  ldx level	 ;Load the level and reduce it by 1
  dex level
  txa	 ;Multiply the level by 2 for the offset
  asl
  tax
  lda lvlvectors,x ;Get the address of the level data
  sta level_vec
  lda lvlvectors+1,x
  sta level_vec+1
  ldy #$00
getscrnchr lda (level_vec),y   ; <---- THIS LINE HERE GENERATES THE ERROR
  cmp #$FF
  beq leveldone
  tax
  and #$0f
  clc
  adc #$40
  sta outchar
  txa
  lsr
  lsr
  lsr
  lsr
  tax
  lda outchar
rptscrnchr cpx #$00
  beq getscrnchr
  sta (level_vec),y
  iny
  dex
  jmp rptscrnchr
 
  ;  ++++++ HERE ++++++
leveldone lda #$00   ;Temporary instruction
  rts

I know it's probablu quite messy, but this is my first real assembly project.

However, when I try to run the assembler, it tells me that I have an illegal addressing mode on the indicated line. I though that indirect-indexed was allowed for LDA.

Any help please

March 8, 2012

I was having some trouble with Quick, setting up game screens and stuff, so I am going to take the plunge and try to code my current project in assembly.

March 8, 2012

Well, thanks to this thread. I have now written my first 6502 assembly program.

It's very simple, just a screen of text (mixed modes), with some flashing text. The timing for the flashing is done in a VBI, which is doubly amazing for me.

I am so chuffed

March 8, 2012

Slightly off topic here.

But if you could have an ideal IDE for A8 development, what features would you like?

March 8, 2012

After reading through this thread, I have now also added MADS, WUDSN and Eclipse, but this is mainly for learning assembly at the moment.

March 6, 2012

I'm quite surprised that 4 out of the 5 answers so far are from people coding directly on A8 hardware (myself included).

I thought more people were using cross compilers these days.

March 6, 2012

Here's a question, did the A8 have any software 80 column mode programs in the early 80s?

I don't know about any commercially available software, but Atari User did publish a type in for 80 column text to be used with your own basic programs.

March 6, 2012

Guess I'll be the first to answer this.

This is my first A8 project to actually get any momentum since the 80's, so things may change after this one.

Right now, I am developing directly on my 800XL, using the Quick language.

When testing, I use Atari800MacX, because of its built in monitor and debugging tools.

March 6, 2012

I get the same and if I FTP direct, I just get connection failed.

March 6, 2012

DLI's happen on the last line (or only line) for the specified mode, allowing you to make changes before the next line starts. Usually a WSYNC is used to align with the HBLANK area.

http://www.atariarch...ere/chapt05.php

Right, so if I have a displaylist containing:

...,135,2,...

Then, if I make a colour change, it won't effect the mode 7 line that the interrupt is on, but it will effect the mode 2 line following it. Is that right?

Sorry if these are basic questions, but I've not really dealt with interrupts before.

March 5, 2012

I'm a little confused about Display List Interrupts.

If I have a display list as follows:

 DATA($7000)
 [
   112,112,112,72,$94E8
   8,8,8,8,8,8,8,8,8,8,8
   8,6,6,6,6,135,6,7
   65,$7000
 ]

Should the interrupt effect the third to last line (135) or the following line (6)?

March 5, 2012

If you are looking at coding in assembly, I have managed to get working versions of MADS, ATASM and ZASM.

I can send you the binaries if you like.

March 3, 2012

Thanks for the tip Rybags. I can't use Altirra though (I'm on a mac), but atari800MacX does have a decent monitor and debugger.

What I discovered is that the displaylist, which should be entered into memory with

DATA($7000)
[
 112,112,112,71,232,148
 7,7,7,6,6,6,6,7,7,7,65,0,112
]

doesn't seem to be in memory. Not sure why. I tried out one of the demo games that is available on the AtariWiki, and that fails to put the display list in memory. Looks like there could be a problem with Quick itself.

Edit: Just tried with Quick 2.1 (I was using 2.2) and the data is now being stored in memory.

March 2, 2012

Just spotted one thing...the last byte of the display list should have been 112, not 70. But but still doesn't work

March 2, 2012

Should have mentioned... the colours look great on a Pal system.

March 2, 2012

Works brilliantly. I love the new front screen.

The screen corruption that I saw before has now gone as well.

March 2, 2012

I need some help fro anyone out there who knows Quick.

I have taken a page from XXL's book and am trying to port some simple spectrum games to A8. Unlike XXL, I am not using assembly, I will be using the Quick language. In theory, this should be straight forward, but I have already hit a snag.

I am trying to create a custom display list (actually, there will be 2 in the game, but one at a time here).

I 'think' it is creating the correct list, but when I try to poke a character to the screen, I get nothing.

I tried virtually the same in TurboBasic and I got a character on the screen. Could any one help?

I am posting the code to both the Quick and the TurboBasic versions so maybe someone could see something.

Quick Code

BYTE
[
 DMACTL=559
]
WORD
[
 SDLSTL=560
 MENUDLI
 MENUSCRN
]
* FRONT MENU DISPAY LIST
DATA($7000)
[
 112,112,112,71,232,148
 7,7,7,6,6,6,6,7,7,7,65,0,70
]
MAIN
 MENUDLI=$7000
 MENUSCRN=$94E8
 .FRONTMENU
ENDMAIN

* DISPLAY FRONT SCREEN
PROC FRONTMENU
LOCAL
WORD
[
 PKPOS
]
BEGIN
 DMACTL=0
 SDLSTL=MENUDLI
 DMACTL=34
 CLR($70,1)
 ADD(MENUSCRN,56,PKPOS)
 POKE(PKPOS,65)
ENDPROC

TurboBasic Code

1 DMACTL=559:SDLSTL=560:MENUDLI=28672
2 MENUSCRN=38123
3 HSBMENU=INT(MENUDLI/256)
4 LSBMENU=(MENUDLI-(HSBMENU*256))
10 FOR F=0 TO 18
20   READ A
30   POKE MENUDLI+F,A
40 NEXT F
100 POKE DMACTL,0
110 POKE SDLSTL,LSBMENU
120 POKE SDLSTL+1,HSBMENU
130 POKE DMACTL,34
150 POKE MENUSCRN,99
1000 DATA 112,112,112,71,232,148,7,7,7,6,6,6,6,7,7,7,65,0,70

Any help would be very greatly appreciated.

February 28, 2012

I'll be lucky if I get to level 6!

February 27, 2012

Atari 8-bit

Pac-Man

Donkey Kong

ST

PacMania

Sega Saturn

Virtua Fighter

February 27, 2012

Strange I never saw this thread before, even stranger that I found out about these 'electronic novels' last night.

Thanks to Sio2OSX, I am going to give the one not mentioned yet a try, Brimstone.

If anyone is interested, I'll post my thoughts in this thread when I've had a chance to really get to grips with it.

Like Gunstar, I would also like to get hold of originals of these, but I've never seen them in the wild.

February 26, 2012

Here's my first attempt: 10650

Quite proud of that

February 25, 2012

Thanks for confirming that for me Dan. I wasn't sure if the DLI would also work with the PMGs, but now I know.

February 25, 2012

I'm playing Bounty Bob right now, and I just did a 'head-count' of the number of sprites that are definitely PMGs. I count 6. Now, I know a fifth player can be created by combining missiles, or even 2 small sprites by making 2 pairs of missiles, but these appear to be full size players.

Am I right in thinking that this can be achieved by creating multiple copies of the sprite image in a single player, then changing the horizontal position of the player by using a DLI? or doesn't this apply to PMGs?

February 23, 2012

I'm getting better at this:

H.E.R.O. - 55780

Profiles

Forums

Blogs

Gallery

Events

Store

Posts posted by Pengwin