Wrathchild

tbf, memorize the 6502 hex code and mnemonics, then when staring a hex dump / file you've spot the the patterns such as A9 XX 8D YY XX and distinguish runs of instructions from data. like anything, practice, practice, practice.

but there are many different coding styles you'll come across. you'll see lots of inline reserving of data bytes between functions but then you'll also see data defined separately in, say, contiguously across a specific page or more of memory.

April 24

Maybe uses something like the 'move' command given in this example:

#NotAFanOfPeekPokeOutsideOfBasic (but I get it)

April 21

4 minutes ago, CharlieChaplin said:

If your ML-file should load under DOS

To expand upon this, it makes sense to explain that if you intend to make use of DOS functions then do not utilise that memory area either along with ZP, page 3 locations used by the DOS/OS in relation to I/O.

It is OK to use DOS to load and run from $2000 (and above) but then discard and overwrite lower memory so long as you don't intend to return cleanly.

April 21

In the latest help file is:

/distance=Color distance function
  Default: yuv, other options: euclid, ciede

However I can still use cie94?

April 18

On 4/16/2024 at 11:52 PM, TJ76 said:

SIO2USB

Can you clarify here if you mean SIO2PC-USB cable version as SIO2USB is a specific device permitting a USB pen/flash drive to be plugged into the unit and files selected from it and read over SIO.

April 16

DOS friendly version

With downloads, Chrome is blocking but seems to simply leave the file in the download folder as something like "Unconfirmed 198598.crdownload" and so you rename that back to the download name then it is fine. Or use a browser such as "Brave" alongside and copy the download link across to that.

mazeam_exomizer.xex

April 15

Spy Hunter (2nd player uses 2nd joysticks fire?)

April 14

Does it fail if loaded from, say, an SIO2SD device rather than the A8PicoCart?

The Pico would be responsible for loading the game but once control is passed to it, the Pico isn't involved.

The game itself is doing some fun stuff with the scroll registers via the Display List interrupts:

      - NMI interrupt (DLI)
          7016: 69: 99 | A=05 X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7016: 79:100 | A=0A X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7016:104: 99 | A=0F X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7016:114: 99 | A=05 X=F4 Y=FF (   I C) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7016:124:100 | A=0A X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7016:149: 99 | A=0F X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7016:159: 99 | A=05 X=F4 Y=FF (   I C) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7016:169:100 | A=0A X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7016:194: 99 | A=0F X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7016:204: 99 | A=05 X=F4 Y=FF (   I C) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7016:214:100 | A=0A X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (VBI)
          7016:248: 81 | A=05 X=F4 Y=FF ( V I  ) | 41CD: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7017: 69:100 | A=0A X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7017: 79:101 | A=0F X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7017:104: 99 | A=05 X=F4 Y=FF (   I C) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7017:114:100 | A=0A X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7017:124:101 | A=0F X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7017:149: 99 | A=05 X=F4 Y=FF (   I C) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7017:159:100 | A=0A X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7017:169:101 | A=0F X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7017:194: 99 | A=05 X=F4 Y=FF (   I C) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7017:204:100 | A=0A X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL
      - NMI interrupt (DLI)
          7017:214:101 | A=0F X=F4 Y=FF (   I  ) | 41A2: 8D 04 D4          STA HSCROL

And the actual Display List is a little unconventional:

  4068: x3   blank 8
  406B:      mode 2 @ 0780
  406E:      mode 2
  406F:      blank.i 1
  4070:      mode C @ 4CF5
  4073:      mode 4 @ 2004
  4076:      mode C @ 4D01
  4079:      mode C
  407A:      mode.h 4 @ 2020
  407D:      mode C @ 4D1C
  4080:      mode.i C
  4081:      mode.h 4 @ 2040
  4084:      mode C @ 4D37
  4087:      mode.i C
  4088:      mode.h 4 @ 2060
  408B:      mode C @ 4D51
  408E:      mode C
  408F:      blank 4
  4090:      mode C @ 4CF5
  4093:      mode 4 @ 2084
  4096:      mode C @ 4D01
  4099:      mode.i C
  409A:      mode.h 4 @ 20A0
  409D:      mode C @ 4D1C
  40A0:      mode.i C
  40A1:      mode.h 4 @ 20C0
  40A4:      mode C @ 4D37
  40A7:      mode.i C
  40A8:      mode.h 4 @ 20E0
  40AB:      mode C @ 4D51
  40AE:      mode C
  40AF:      blank 4
  40B0:      mode C @ 4CF5
  40B3:      mode 4 @ 2104
  40B6:      mode C @ 4D01
  40B9:      mode.i C
  40BA:      mode.h 4 @ 2120
  40BD:      mode C @ 4D1C
  40C0:      mode.i C
  40C1:      mode.h 4 @ 2140
  40C4:      mode C @ 4D37
  40C7:      mode.i C
  40C8:      mode.h 4 @ 2160
  40CB:      mode C @ 4D51
  40CE:      mode C
  40CF:      blank 4
  40D0:      mode C @ 4CF5
  40D3:      mode 4 @ 2184
  40D6:      mode C @ 4D01
  40D9:      mode.i C
  40DA:      mode.h 4 @ 21A0
  40DD:      mode C @ 4D1C
  40E0:      mode.i C
  40E1:      mode.h 4 @ 21C0
  40E4:      mode C @ 4D37
  40E7:      mode.i C
  40E8:      mode.h 4 @ 21E0
  40EB:      mode C @ 4D51
  40EE:      mode C
  40EF:      waitvbl 4068

So I would think timing is pretty critical here and potentially there is a slight glitch when the game starts before the correct display is rendered.

This can be seen in Altirra by setting a breakpoint at the launch address (3FD3) and then using 'gv' to step a frame at a time.

I see this, or variants of, or sometimes no problem (due to using Altirra's "Randomize program load timing" setting):

These generally pass quickly and the user barely notices them, however I was looking at the launching of the Kangeroo prototype recently on Incognito and experienced different results in different profiles, so wonder if something locks up instead.

I don't know (or think he doesn't) if @phaeron has an 800 with Incognito or any idea what might be happening here? Or if anyone else with one is able to better diagnose things, e.g. with a scope.

April 13

Chimera had a nice clam shell too

April 12

Can you attach a single example of a failing xex?

6 hours ago, Spudster said:

ran some XEX file tests

April 12

4 minutes ago, tonma said:

And if we can use sc card on 400 with 8ko ram + dos, do we have enough space ?

Don't rule out using an 8K ROM, any self-modifying code and DATA / SCREEN RAM can be located in low memory but most code will happily run from ROM.

The vast majority of users these days will have a device that can run a ROM image

April 11

This is also true of XEX loaders used in most cart devices, SIDE Loader etc. These tend to load the XEX loader bootstrap to $700 and so writing over that area during the loading is going to crash things.

April 11

Have a go with running it through exomizer to produce a single part loader @ $2000 which is fine for most DOS's. e.g.

exomizer sfx $600 -n -t 168 -Di_table_addr=$500 -Di_load_addr=$2000 -o mazeam_exomizer.xex mazezam.xex

mazeam_exomizer.xex

April 10

Harry, I think the OP has moved the discussion on a bit from memory considerations to specifics about scroll memory management

April 9

plus the available test is a quick OR of the lo/hi bytes being zero

April 9

Rather than the tag being a yes/no, could be a count that is inc'd / dec'd but then the problem simply becomes "you can't have it appearing more than 255 times" 😄 (but seeing at there are only 128 characters you you put hi/lo counter bytes into a single page)

April 2

Syntax isn't that far away from MADS so was easy to manipulate. I built using:

mads -l:sr.lst -o:StarRaiders.rom StarRaiders.asm

StarRaiders_MADS.zip

March 31

7 minutes ago, Tempest said:

Are there any other 400/800 only games that haven't been converted to run on an XL?

There were a couple @CharlieChaplin mentioned (a "Q-Bert" and "Satarn Saturn") here that weren't addressed?

March 31

2 hours ago, Tempest said:

That one does not work.

I've re-packed this with exomizer, give this one a go.

I think the issue with existing binaries is that there is a short period where the dlist is 'random' and so crashing could depend on timings as to whether or it muscles through.

Kangeroo-exomizer.xex

Profiles

Forums

Blogs

Gallery

Events

Store

Posts posted by Wrathchild