HAL PCG-6500 Graphics Board
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GALAXIAN on the PCG-6500, a display not possible with standard PET character graphics.The HAL PCG-6500 is a programmable character set generator and sound device for PET/CBM computers, developed by HAL Laboratory in Japan. It was distributed in the USA by Systems Formulate Corporation of Palo Alto, California.
PET/CBM computers do not have bitmap graphics capability and do not have the ability to reprogram the character set. Games must be constructed using only the built-in characters. The PCG-6500 allows software to reprogram 64 of the characters with custom ones, resulting in higher quality graphics like the GALAXIAN screenshot above. The PCG-6500 also provides a speaker for CB2 sound.
Operation
The PCG-6500 was designed for the PET 2001 series and is housed in an metal enclosure designed to sit on top of a 2001’s 9″ monitor. It has two cables that attach to the PET: one goes inside and plugs into the character ROM socket, the other goes to a card edge connector that plugs into the user port. The original character ROM is relocated to the inside of the PCG-6500. Characters are reprogrammed by sending the data to the user port. The protocol is described in the User’s Manual below.
Reverse Engineering
Git Repository with disassemblies of PCG-6500 programs.
Resources
Credits
The PCG-6500 was rediscovered when Jim Oldfield Jr. sent me his collection of PEDISK II disks for recovery. I found the PCG-6500 programs on these disks. Jim then found the PCG-6500, sent photos, and scanned the manual.