Panasonic HHC ROM 'capules'

[Paul Berger (Canada)]

(01-06-2023 06:55 AM)brouhaha Wrote:  

(01-03-2023 05:19 PM)Jeff_Birt Wrote:  you can't create SnapFORTH programs without the SnapFORTH 'ROM capsule'. (But you can run them without it.)

The SnapFORTH development ROM was 16KiB and wouldn't fit in a capsule. It was an expansion box, about the same size as e.g. the RS-232 expansion box, but without an I/O connector. Inside there are EPROMs and logic for bank-switching.

The Snapforth was very definitely released as a capsule I have one along with the Snap BASIC and Microsoft BASIC. The HHC bank selects the capsule ROMs by switching the power pin and for the 16K capsules they use what would normally be the -E pin as an address line. One thing that it occurs to me that they may have done was mounted the dies for a "normal" 16K ROM in a 24 pin package and internally wired bonded the enable pin so that it would always be enabled when the powered up.

Paul.