3 replies to this topic

[Tony Knerr]

Here's something I found from 15 years ago, and seems appropriate to post to this "games-centric" group.

            CONVERT ATARI GAMES ON DISK TO RUN WITHOUT SPECIAL LOADER
         ---------------------------------------------------------------

         by Tony Knerr, 01-26-96.

         Do you have the disk or disks with the Atari games that load
         from Extended Basic? If you do, I'm sure you're not really
         pleased with that loader (it seems to take about an hour and a
         half to load that object code!) Well, hope is in sight, those
         files can be converted rather easily to work from
         Editor/Assembler option 5 or any other similar program image
         loader like FUNNELWEB or XBOPT5. The game files are already in
         program image format, they just don't contain the necessary
         file header information on where to load and where to start
         execution. The loader decides where to load the game and where
         to begin execution. Fortunately the first few bytes of each
         game file are not used by any of the programs and we can change
         them to the necessary file header information. (For those who
         are interested, the first 20 or 30 bytes are the Cartridge
         headers left over from when the games were in Cartridge form.)
         To make the changes use a sector editor or file editor (Disk
         Utilities works real well) to edit the beginning bytes of each
         file as listed in the chart below. You'll find that the files
         usually start with something like AAFF 0000 0000 or AA01 0000
         0000 or AA01 0100 0000. if you see that sort of information,
         you'll know you're at the start of the file. Replace the string
         at the start of the file with the string from the chart, and
         write the sector back to the disk. For two-file games, you need
         to change both files. Please do not use your original disk to
         make the changes, copy the files to another disk and work with
         the copy disk in case you make a mistake! After the changes are
         made, you can load the games from Editor/Assembler option 5 (or
         equivalent) by running the file ending with a 1. For example,
         type "DSK1.DK1" <enter> from the "File Name ?" prompt to run
         "DONKEY KONG" after selecting 5 from the Editor/Assembler menu.
         The games load and run now without the need of the special
         loader. We also have the added bonus in that the games will
         still run from the special loader, the changes do not affect
         the operation of the loader. Happy game playing!

         Game                File(s)             Patch to Start of File
         ----                -------             ----------------------

         Centipede           CP1                 0000 1FFA A006 0460 A056

         Dig Dug             DD1                 FFFF 1FFA A006 0460 C03C

                             DD2                 0000 1FFA C006

         Defender            DF1                 0000 1FFA A006 0460 A072

         Donkey Kong         DK1                 FFFF 1FFA A006 0460 A086

                             DK2                 0000 0FFA C006

         Jungle Hunt         JH1                 FFFF 1FFA C006 0460 C020

                             JH2                 0000 1FF4 E006

         Moon Patrol         MP1                 FFFF 1FFA C006 0460 C0FE

                             MP2                 0000 1FF4 E006

         Ms Pacman           MS1                 FFFF 1FFA C006 0460 E0AE

                             MS2                 0000 1FF4 E006

         Pacman              PM1                 FFFF 1FFA A006 0460 A052

                             PM2                 0000 0FFA C006

         Pole Position       PP1                 FFFF 1FFA A006 0460 A060

                             PP2                 0000 1FFA C006

         Protector 2         PT1                 FFFF 1FFA C006 0460 DE3A

                             PT2                 0000 1FF4 E006

         Shamus              SH1                 FFFF 1FFA A006 0460 CBDA

                             SH2                 0000 10FA C006

Edited by Tony Knerr, Sat Aug 20, 2011 6:24 PM.

[Tony Knerr]

I struggled a bit with my article post, which was originally written in a fixed width font.
The only way I found to post it in the proper format was to post it as code. Using a fixed
width font (courier new) did not preserve the necessary spaces. Is there a way to preserve
a fixed width font with spaces here, or is that a limitation of this forum? (and a painful
limitation, at that).

Tony

[sometimes99er]

Using a text editor I replaced 9 spaces with one, and linefeed with a single space, and got this. Was it something like that you were looking for ?

Do you have the disk or disks with the Atari games that load from Extended Basic? If you do, I'm sure you're not really pleased with that loader (it seems to take about an hour and a half to load that object code!) Well, hope is in sight, those files can be converted rather easily to work from Editor/Assembler option 5 or any other similar program image loader like FUNNELWEB or XBOPT5. The game files are already in program image format, they just don't contain the necessary file header information on where to load and where to start execution. The loader decides where to load the game and where to begin execution. Fortunately the first few bytes of each game file are not used by any of the programs and we can change them to the necessary file header information. (For those who are interested, the first 20 or 30 bytes are the Cartridge headers left over from when the games were in Cartridge form.) To make the changes use a sector editor or file editor (Disk Utilities works real well) to edit the beginning bytes of each file as listed in the chart below. You'll find that the files usually start with something like AAFF 0000 0000 or AA01 0000 0000 or AA01 0100 0000. if you see that sort of information, you'll know you're at the start of the file. Replace the string at the start of the file with the string from the chart, and write the sector back to the disk. For two-file games, you need to change both files. Please do not use your original disk to make the changes, copy the files to another disk and work with the copy disk in case you make a mistake! After the changes are made, you can load the games from Editor/Assembler option 5 (or equivalent) by running the file ending with a 1. For example, type "DSK1.DK1" <enter> from the "File Name ?" prompt to run "DONKEY KONG" after selecting 5 from the Editor/Assembler menu. The games load and run now without the need of the special loader. We also have the added bonus in that the games will still run from the special loader, the changes do not affect the operation of the loader. Happy game playing!

[sometimes99er]

To retain multiple spaces I think there's only one way, and that is using the "code" control in the forum editor.

Game           File(s)  Patch to Start of File
-------------  -------  ------------------------
Centipede      CP1      0000 1FFA A006 0460 A056
               
Dig Dug        DD1      FFFF 1FFA A006 0460 C03C
               DD2      0000 1FFA C006
               
Defender       DF1      0000 1FFA A006 0460 A072
               
Donkey Kong    DK1      FFFF 1FFA A006 0460 A086
               DK2      0000 0FFA C006
               
Jungle Hunt    JH1      FFFF 1FFA C006 0460 C020
               JH2      0000 1FF4 E006
               
Moon Patrol    MP1      FFFF 1FFA C006 0460 C0FE
               MP2      0000 1FF4 E006
               
Ms Pacman      MS1      FFFF 1FFA C006 0460 E0AE
               MS2      0000 1FF4 E006
               
Pacman         PM1      FFFF 1FFA A006 0460 A052
               PM2      0000 0FFA C006

Pole Position  PP1      FFFF 1FFA A006 0460 A060
               PP2      0000 1FFA C006

Protector 2    PT1      FFFF 1FFA C006 0460 DE3A
               PT2      0000 1FF4 E006

Shamus         SH1      FFFF 1FFA A006 0460 CBDA
               SH2      0000 10FA C006