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Favorite obscure game


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Caves of Kafka (spelling)

 

Buried Bucks (obscure, maybe not)

 

H2O - just found this one - pretty fun

 

Escape from Vulcan Isle (and Nightmare the Haunted House version)

 

Atom Smasher

 

 

Im sure Ill think of a few others I enjoyed back in the day ;)

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Hi,

 

Quite an odd co-incidence this question popping up now.

I've just today finished correcting 'Attack at EP-CYG-4' so that it

works on the XL/XE machines. ROM/ATR and EXE attached. :)

 

The problem was only that the text was corrupting due to Romox

using 4 bytes from the OS to alter the text byte put to the screen.

The offending pattern was (in hex) 40, 00, 20, 60. In OS.B this is

located at $FEF6 and in the XL its located at $FB49. To fix it, I placed

these bytes at an unused area of the ROM ($A0A2) and changed the

reference of the ORA instruction at $97EA.

 

I think 'Shamus I' may have been fixed already, but I'm going

to have a look into that one too tonight.

 

Any other requests for fixing non-XL games? :twisted:

 

Mark

attackatepcyg4.zip

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Hi,

 

Quite an odd co-incidence this question popping up now.

I've just today finished correcting 'Attack at EP-CYG-4' so that it

works on the XL/XE machines. ROM/ATR and EXE attached.  :)  

 

The problem was only that the text was corrupting due to Romox  

using 4 bytes from the OS to alter the text byte put to the screen.  

The offending pattern was (in hex) 40, 00, 20, 60. In OS.B this is  

located at $FEF6 and in the XL its located at $FB49. To fix it, I placed  

these bytes at an unused area of the ROM ($A0A2) and changed the

reference of the ORA instruction at $97EA.  

 

I think 'Shamus I' may have been fixed already, but I'm going

to have a look into that one too tonight.

 

Any other requests for fixing non-XL games?  :twisted:  

 

Mark

 

Fix Slime and Gorf for the XL/XE series :) - Slime was another great game - Add Cavelord to that list also!

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Fix Slime and Gorf for the XL/XE series  - Slime was another great game - Add Cavelord to that list also!

 

I've seen Slime mentioned alot so I might do that.

 

Just fixed Black Hawk :D

 

It had a direct jump to $E7AE instead of going through SYSVBV!

All for the sake of saving a few cycles...

Anyhow, I take it all the flashing in this game is because your crashing?

 

Shamus next...

 

Mark

blackhawk.zip

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Fix Slime and Gorf for the XL/XE series  - Slime was another great game - Add Cavelord to that list also!

 

I've seen Slime mentioned alot so I might do that.

 

Just fixed Black Hawk :D

 

It had a direct jump to $E7AE instead of going through SYSVBV!

All for the sake of saving a few cycles...

Anyhow, I take it all the flashing in this game is because your crashing?

 

Shamus next...

 

Mark

 

Very cool stuff. Thanks for doing these.

 

-Bry

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Fix Slime and Gorf for the XL/XE series  - Slime was another great game - Add Cavelord to that list also!

 

I've seen Slime mentioned alot so I might do that.

 

Just fixed Black Hawk :D

 

It had a direct jump to $E7AE instead of going through SYSVBV!

All for the sake of saving a few cycles...

Anyhow, I take it all the flashing in this game is because your crashing?

 

Shamus next...

 

Mark

 

Thanks for the fix! now I can load it straight away without the translator! the flashing is exactly the same as Blue Max, it's to let you know that your getting VERY close to the ground and if you don't pull up, you may crash.

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Hi again,

 

Not a bad day today, fixed a few client issues at work

and now this... yep, Shamus has been tamed!

 

This was a pain to debug, but here's the explaination.

 

During the title screen the music is played via a timer interrupt.

This is located at $63A and looks like:

 

PHA

TXA

PHA

TYA

PHA

LDA #3

STA SKCTL

LDA #0

STA AUDCTL

JSR sub_0_69B

STA CDTMV1

PLA

TAY

PLA

TAX

RTI

 

Being vectored through CDTMA1 ($226), this is supposed to

close with an RTS, not an RTI. However...

 

In OS.B this returns to a legitimate instruction (INX) and so the

program continues oblivious to the mess-ups.

On the XL/XE the RTI isn't so lucky and hits an illegal op-code.

 

I've replaced the RTI with a PLA,RTS - which meant shifting

a small part of the code back a byte and then correcting the LDA

for the loading of $226 from $3A to $39.

 

Anyway, you don't need to worry about that, just download the

new executable and enjoy!!

 

8)

 

Mark

shamusfixed.zip

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...Being vectored through CDTMA1 ($226), this is supposed to close with an RTS, not an RTI. However...

 

No way dude. It must be closed with PLA,RTI !!!, when you're using the OS IRQ servicing routine.

 

When the IRQ occurs, the first thing the IRQ handler does is PHA. So after an IRQ it must be pulled off (PLA), then RTI. Although, as far as I remember, there might be trouble with the BRK-flag, because it forces the CPU in an IRQ-loop. (I had that experience with playing digital sound)

 

By the way. It's very weird to play music synchronised by a Timer IRQ. It uses one of the soundchannels. :ponder:

 

-----

mux

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Apology accepted ;)

 

The trick to it working previosuly was that RTI restores the

status (P) register. Actually they were popping the first PHA into P!

Then, upon return, the popped X is incremented. As the game loop

is simply sitting waiting for some console key to be pressed, nothing

gets upset (except he should have put an SEI/CLI around the check).

 

Mark

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It has come to my attention, by playing the game myself yesterday, that the version of Black Hawk I posted, and presumeably the one fixed by Wrathchild, is a Kilroy hack that apparently makes the player invulnerable.

This to me, ruins the game, as I find no fun in playing a game you can't lose! I haven't yet found the version I've played before that is normal. if anyone tracks it down before I do, please post it. I'm searching my PC right now, as I know I have it someplace... :roll:

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Step aside, make way for the Master Of Obscurity :D

 

I love this one purely for nostalgic reasons--it's an utter POS.

 

"Mar Tesoro" by Ted Clawges, Syncro Software.

 

It was written in BASIC, but it really was a commercial release. It was the first game I bought with my 800, many many years ago.

 

Basically, it's a "sim" type of game where you rent a ship and crew, then explore a map around an island, salvaging shipwrecks and collecting valuables in a desperate attempt to recoup your investment.

 

Good idea, but the execution was SO primitive, and the odds were programmed too high--you almost always go broke and lose.

 

I'd attach the ATR, but I'm at work and it's not handy. Not that you'd want to play it anyway. ;)

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Was there ever a fixed copy of Nautilus?

 

Not sure, but could soon be ;)

 

The problem is the RTI again, however, the loading

routine is a bit clever. The game code/data is interspersed

on the disk with the value 1, but the distance to the next '1'

varies. Hence, if you change any byte then the data gets

loaded incorrectly :(

 

I'm away over the weekend, so I'll have a go on Sunday night.

 

Take care,

 

Mark

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