Jul 172015
 

Im currently working on a Time Pilot PCB and tested out Shoestrings diagnostic ROM.
This board is the Atari version which wasnt supported at the time but has now been updated.
I also ran into a problem where nothing appeared on the screen. Working together we eventually found the issue.
The original game code makes a write of 01 to address $c308. Using the Fluke 9010 I found that this write actually initialises the screen output.
MAME doesnt have any support for this so when testing the ROM in MAME it works fine. The test ROM has been updated with this now too and should work fine.

This highlights the need to test things on REAL hardware.
Thanks to Shoestring for making the diagnostic ROM and for putting up with all my questions.

 Posted by at 5:04 pm

  5 Responses to “Time Pilot diagnostic ROM update”

  1. it would be wise to start adding version numbers to these test-roms.

    • Its Shoestring’s work so don’t want to start messing with it but I agree version numbers or even a checksum of the latest version may be useful.

  2. Writes to $c308 are currently unmapped in the Time Pilot driver (“protection??? stuffs in some values computed from ROM content” – according to the driver). Is it only the Atari version that writes to $c308 or do the Konami/Centuri versions write to that address too?

    I can’t stress the importance of testing on real hardware enough. I’ve developed so many routines that work perfectly in MAME and fail abysmally when deployed to hardware.

    • All the versions write the same value to the same address.
      I’ve sent the findings to dev’s so its up them if they include it or not but a note in the source should at least be added IMO.

  3. Noted.

    My Track & Field test ROM is currently in development and it’s looking good so far, it also includes a version number & I will make a habit of including that on the title screen in the future. Critique is always welcome.