C64 - Impossible Mission On Blu?


Morwynd

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One of my favourite games of all time is Impossible Mission on the C64. In fact this is one of the major reasons I purchased a GP32, to be able to play this on a handheld.

Well, it worked just fine on my FLU. But I have been completely unable to get it working on my BLU. I have tried many different versions of Frodo, several different firmwares, things like enabling 1541 emulation, and tried many different versions of the actual D64 file, but with zero success.

This is what happens every time:

The game seems to load properly, the title screen comes up OK, but when the game itself should start, the C64 resets. (That is, the EMULATOR resets, not the entire GP32) If I go to the Frodo debug console, I see this:

Code:
opening d64 file in write mode
Jump to I/O space at 7F73 to DD03. : Reset
I am currently running Slubman's new BLU firmware, and the standard v12 version of Frodo. (I tried the special BLU version of Frodo v12, which is supposed to fix a display problem, but in fact it CAUSES a display problem on mine.. the whole screen is shifted vertically and wraps around)

Any help or suggestions would be very much appreciated. Does Mike Dawson frequent these forums? There's not much in the way of support at his official Frodo site, so I came here. Think I should email him directly?
 
i have it too on my BLU+ version i can actually get it working
sometimes when you try load it the c64 reboots if so i reload the game again and keep trying and trying evntually it does work i would give you a save state or something so youd bypass the problem but for some reasion the save states dont work for me ..

the sound on the game isent perfect but kinda funny ish when you fall down a hole and he goes AAAAAAAAAGHHHHHHHHHHH :D

the firmware im using is windups+multifirmware with the bios ripped out and switched with a BLU+ one for bar bug fix.......


Steve
 
I haven't had any experience of using Slubman's Firmware, so maybe that's a factor, try launching Frodo from something like Pacrom...?

®
 
Well I tried the multiFW & Pacrom, didn't help. (BTW, you should really try Slubman's)

So then I downloaded the Frodo source code, (I am an experienced coder, although never on the GP32, and my C is rusty as hell) determined to find what was throwing the error.. and while searching for that error string I found the file 'flavours.html' which offers the following:

The improved line-based emulation 'Frodo PC'

Frodo PC is also a line-based emulation but it has some improvements over the standard Frodo:
  • Code in chip registers can be executed
  • Correct calculation of 6510 instruction cycles
  • More precise CIA emulation
Programs that don't work on the standard Frodo or that produce an "Illegal jump to I/O space" message might work with Frodo PC. However, Frodo PC is a bit slower.

Bang, problem solved. Why he doesn't have this file displayed prominently on his web page, or even in the Frodo distro, is beyond me.

This makes perfect sense since the error being thrown is complaining about a jump to I/O space DD03, which are shared control registers for the VIC chip, and one of FrodoPC's differences is the ability to execute code in register space.
 
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