Bomber Word discovered!

History and Preservation Issues

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nbla000
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Postby nbla000 » Sun Feb 05, 2012 8:18 am

OK, option 5 LOAD FROM CASSETTE fixed.

Change the code in $AF42 from:

Code: Select all

af42   A2 FF      LDX #$FF
af44   78         SEI
af45   9A         TXS
af46   D8         CLD
af47   4C 54 AF   JMP $AF54


to:

Code: Select all

af42   A2 FF      LDX #$FF
af44   78         SEI
af45   9A         TXS
af46   D8         CLD
af47   4C 2F FD   JMP $FD2F


By changing the JMP in $AF47 we substitute the internal "exit to basic" code to the standard vic-20 start sequence code so the standard Vic-20 prompt appears and we can load the data file from tape or disk:

LOAD"WORDS",8,1

Then by hitting [RESTORE] (Page UP on VICE) the game restarts and you may select option 4 CASSETTE WORDS successfully.

I've used the e5frog 4K fixed version (with $a000 $a001 fixed pointers) so for the full fixed ROM, by starting from the original 8K dumped rom, you need only the first 4K then these changes:

From:

Code: Select all

a000   2f fd

af47   4C 54 AF   JMP $AF54

afae   FD FD FD   SBC $FDFD,X
afb1   FD FD FD   SBC $FDFD,X
afb4   FD FD FD   SBC $FDFD,X


to:

Code: Select all

a000   ae af

af47   4C 2F FD   JMP $FD2F

afae   20 8D FD   JSR $FD8D
afb1   20 18 E5   JSR $E518
afb4   4C 4A AF   JMP $AF4A


As buzbard said, the data file address starts from $1800 and the data file format is 8 letters for each word (spaces used for lower letter's words)

Example:

Code: Select all

HOUSE   STRENGTHMIRROR  COMPUTERCALENDARTOWEL   DENIM   TWENTY  GUESS   TRIBE   

There is a fixed number of words (without end markers) in the data file, the max lenght file is $600 bytes HEX = 1536 bytes / 8 bytes for each word = 192 words.
so the last byte used in memory is $1DFF, from $1E00 starts the video memory of course.

It seems there is also an easter egg/hidden text in this cartridge:

Code: Select all

RECRUIT BEACON  COSMOS  SWAP    AVER    WARRANTYDISK    HEXAGON GAZEBO    1982 CHARLES GOLDMAN

This is a text sequence at the end of $600 bytes in rom and it sounds strange to me, what do you think ?
Maybe Charles Goldman is the Programmer and 1982 the year ? and the other words ? who knows ?
Mega-Cart: the cartridge you plug in once and for all.

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buzbard
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Postby buzbard » Sun Feb 05, 2012 10:53 am

nbla000 wrote:It seems there is also an easter egg/hidden text in this cartridge:

Code: Select all

RECRUIT BEACON  COSMOS  SWAP    AVER    WARRANTYDISK    HEXAGON GAZEBO    1982 CHARLES GOLDMAN

This is a text sequence at the end of $600 bytes in rom and it sounds strange to me, what do you think ?
Maybe Charles Goldman is the Programmer and 1982 the year ? and the other words ? who knows ?


I initially copied those words as well to the cassette words list, but when the file is loaded you can see the words appear at the top of the screen. They get deleted as soon as the screen is cleared by the program, so I took them out.

Yes, I agree, Charles Goldman is the programmer and 1982 is the year.
If you look at the picture that Mayhem posted in the first post, you can see "COPYRIGHT ©1982" on the sticker.

I've also noticed a glitch in the ROMs word list. The word AFFLUENT starts at $AE6F which is not evenly divisible by 8, it should start at $AE70 which is evenly divisible by 8.

So this:

Code: Select all

00000E60  42 4C 49 54 5A 20 20 20-4D 49 58 45 53 20 20 41  BLITZ   MIXES  A
00000E70  46 46 4C 55 45 4E 54 20-43 49 47 41 52 20 20 20  FFLUENT CIGAR   

should look like this:

Code: Select all

00000E60  42 4C 49 54 5A 20 20 20-4D 49 58 45 53 20 20 20  BLITZ   MIXES   
00000E70  41 46 46 4C 55 45 4E 54 43-49 47 41 52 20 20 20  AFFLUENTCIGAR   

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Mayhem
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Postby Mayhem » Sun Feb 05, 2012 11:04 am

Ian only had the cartridge, so can't help there with instructions etc. Great work on the patching though :)
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nbla000
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Postby nbla000 » Mon Feb 06, 2012 4:41 am

buzbard wrote:I've also noticed a glitch in the ROMs word list. The word AFFLUENT starts at $AE6F which is not evenly divisible by 8, it should start at $AE70 which is evenly divisible by 8.

So this:

Code: Select all

00000E60  42 4C 49 54 5A 20 20 20-4D 49 58 45 53 20 20 41  BLITZ   MIXES  A
00000E70  46 46 4C 55 45 4E 54 20-43 49 47 41 52 20 20 20  FFLUENT CIGAR   

should look like this:

Code: Select all

00000E60  42 4C 49 54 5A 20 20 20-4D 49 58 45 53 20 20 20  BLITZ   MIXES   
00000E70  41 46 46 4C 55 45 4E 54 43-49 47 41 52 20 20 20  AFFLUENTCIGAR   

Yes I've noticed this too but I've not fixed it because is a nice original bug of the program :wink:

Btw since is a patched version, I may fix it too, what do you think ?
Mega-Cart: the cartridge you plug in once and for all.

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buzbard
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Postby buzbard » Mon Feb 06, 2012 11:40 pm

As long as it's labeled as a "Patched" version, I don't see any harm.

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e5frog
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Postby e5frog » Tue Feb 07, 2012 3:13 pm

Glad you sorted it out and the missing autostart also got its explanation, didn't realize I had done a mistake, but it wasn't a good patch anyway since the load and save didn't work. Will try the new patch instead...

Of course you should fix that bug, strange way of making a list and have an even eight bytes instead of endmarkers after each word. I guess the programmer thought that was easier. Perhaps it could be patched to an 8k cart with a very large word list... ;-)

On the Fairchild Channel F Hangman each letter is coded with five bits, so eight letters in five bytes. Though that was a good space saver - it was fun making a Swedish version of it and encode a new word list.


EDIT:
Uploaded the new nlba000 version here:
http://channelf.se/files/vic/BOMBA04K_patch2.prg
My other interest: http://channelf.se

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e5frog
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Postby e5frog » Tue Feb 07, 2012 4:48 pm

Made a disassembly as well, might be of interest maybe - in case you don't like to do it in VICE.

http://channelf.se/files/vic/BOMBA04K_patch2.7z
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Kweepa
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Postby Kweepa » Tue Feb 07, 2012 6:59 pm

How good is that Interactive Disassembler?
Does the free version (5.0) do everything the 6502 needs?
I would love to disassemble a bunch of games...

Aww, I tried the free version and the demo version and neither disassembles 6502. :cry:

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e5frog
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Postby e5frog » Thu Feb 09, 2012 5:51 am

It's pretty good, it's the only one I have managed to do any 6502 disassembling with apart from the VICE monitor.

There was one called AP, newer understood how it worked.
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nbla000
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Postby nbla000 » Thu Feb 09, 2012 7:23 am

e5frog wrote:EDIT:
Uploaded the new nlba000 version here:
http://channelf.se/files/vic/BOMBA04K_patch2.prg

OK, thank you.

This version fixes the word list error "MIXES" "AFFLUENT" too, we may consider it as the definitive patch.

Maybe I will release an Italian Cassette Word list by editing the buzbard's file with an HEX editor, does someone want to add a own words list ?
Mega-Cart: the cartridge you plug in once and for all.

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nbla000
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Postby nbla000 » Thu Mar 29, 2012 4:03 am

Mayhem wrote:Yeah, he's fine with it. I think he has a Megacart already, he queried being able to get an update at some point...

Mega-Cart firmware updated (rev.21) with "Bomber Word" in the Cartridge Games section.
Last edited by nbla000 on Thu Mar 29, 2012 4:22 am, edited 1 time in total.
Mega-Cart: the cartridge you plug in once and for all.

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e5frog
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Postby e5frog » Thu Mar 29, 2012 4:12 am

Lets hope not as it's called "Bomber Word" because there is bombing of words. ;-)
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nbla000
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Postby nbla000 » Thu Mar 29, 2012 4:37 am

Opss :oops:

Name fixed, thanks for the info :wink:
Mega-Cart: the cartridge you plug in once and for all.

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e5frog
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Postby e5frog » Thu Mar 29, 2012 5:01 am

BTW.... Has there been any recent hardware changes to the Mega-Cart or will it work if I simply download the new version (can I?) and program my spare unused 27C801 roms and swap? (I solder and desolder PLCC32 chips several times per week)
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6502dude
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Postby 6502dude » Thu Mar 29, 2012 8:37 pm

e5frog wrote:.... I simply download the new version (can I?) and program my spare unused 27C801 roms and swap? (I solder and desolder PLCC32 chips several times per week)


Yes, you should be able to update by desolder old roms and soldering new ones in place.
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