Pengo !! Time to add some battery backed RAM to
this classic ! Already using 2k x 8 SRAM on the original game board makes
life a lot easier, simply replace the ROMs and add in an SRAM.
There's a couple of issues, one being the SRAM might not fit into the boards RAM socket very well, in which case a wirewrap socket is required, and the second is a minor pain.....
It appears that the first release/s of Pengo used a Custom CPU, a z80 with some encryption hardware, but the later versions did not and had unencrypted ROMs and a regular z80A CPU. The new game images are designed only for the unencrypted version of the board.
If your board is the first variety with the 'custom
controller' at location IC2 you will need to replace it with a plain z80A, the
'A' is important and a Z80B or Z80C will also work, or a D780 which is an
NEC z80 equivalent.
Source codes !! Yes, I'm sharing the source for this
one ;-) Here are the the source codes to the hack plus note on what
was changed in the original game ROMs.
It's designed for use with the TASM cross assembler for DOS.
Pengo High-Score Save Sources and ROM Patch Details.
High-score table saved to SRAM
1Player start + 2Player start held down simultaneous when powering up the machine will reset the high score table to defaults.
Dallas 1220 battery backed SRAM & 24pin wirewrap socket*
Eight 2732 ROMs with new program images
*if the SRAM does not fit into the socket for IC19 a wirewrap socket will be required.
**with the later Pengo boards the 'custom controller' appears to have been replaced with a regular Z80a CPU, if your board does not have the z80 you WILL need to replace it for the updates to work.
Close up view, Z80 CPU at top in location IC2
Battery backed SRAM at location IC19
|SRAM in 24pin Wirewrap socket||
Socketed SRAM inplace
*NOTE: The new battery backed SRAM replaces the standard 2k x 8 SRAM in
The new program EPROM filenames match the following board locations, all EPROMs are 2732 ( 4k x 8 ).
Download the high-score save Game Program images
Go back to Save Our High Scores