>  I recently acquired an upright BattleZone and was wondering if you had made
>any updates to the BattleZone high score memory conversion before I start on
>it.

Go nice and easy on your board and remember to make it so it can simply
be removed.

I did post an upgrade that got around the problems with test mode, I
suspect you may have the version of the modification without the upgrade.

Good luck, let me know how things go.

-----------------------------------------------
> KNOWN PROBLEMS
> --------------
> 
> The main problem with this patch is that I haven't had a look at the test mode
> code yet, and because the data in ROM 409 has been changed the Battlezone
> test mode spots this and complains. This will not effect normal operation
> but if you put the ROM into test mode you will have problems.
> 
> I may just be a case of juggling the checksums for the ROM so they match
> the original ones, or it may be more complicated. Also the test mode
> might mess with our score locations (while it is testing the RAM).
> I'll be looking into this problem and will post a new patch that will
> pass test mode when I've figured it out (or someone has beaten me to it).
> 
> Until then simply don't enter testmode. If you really need to check things
> out then put the original ROM (and SRAM) back in first.

Anyway here is a version of the patch that will remember the top 3
scores, pass test mode and not corrupt your scores during test mode.

7800          <---- Starting address for ROM 036-409
7FFF          <---- End address for ROM 036-409

7b58 {        <- location of 1st part of patch
  A2 3C A9 00 9D 00 03 E8 D0 FA A0 0A AD 00 08 29 01 
  F0 02 A0 07 A2 1B A9 16 9D 1E 03 9D 1F 03 9D 20 03 
  A9 05 9D 00 03 A9 00 9D 02 03 9D 01 03 CA CA CA 88 
  D0 E2 20 1F 53 4C 00 50 7D
}

7AE6 {        <- location of 2nd part of patch
  EA EA EA
}

7C71 {        <- location of 3rd part of patch
  03
}

Here are the details:

This version permanently preserves the top 3 high scores, and
initailizes the others to "5000 AAA" (unless the right coin
switch is held down during powerup/reset, when it will set all
10 entries to "5000 AAA").

All the bytes in a each Battlezone ROM need to XOR to 0xFF for the ROM
to pass test mode (This is what the 0x7D does at the end of the 1st
section above).

I have prevented the code from checking page 3 (addresses
0x300-0x3FF) during test mode because this scribbles over
the high score locations. But all the checks for the other
areas of RAM are still in there.

Regards, John.

* John Keay                               ! TMS320C80 design       *
* work: keay@tiuk.ti.com                  ! Texas Instruments Ltd. *
* home: john@keay.demon.co.uk             ! Northampton, U.K.      *
* Disclaimer:  All opinions expressed herein are personal. etc etc *