Panasonic HHC ROM 'capules'

[Jeff_Birt]

As luck would have it a few hours after posting my last message an HHC with 4 capsules showed up on eBay so I snatched it up.

Regarding the response time of the ROM. On page 15 of Panasonic_HHC_Technical_Information_of_Hardware.pdf it describes the slow bit which causes a /8 of the Y-driver clock for 'slow' devices, stretching out the high part of the signal. It is not clear yet to me what effect this has. It seems to me that the OS must be smart enough to pause briefly when switching banks.

The above linked page has a basic design for a PCB that is a good starting point.