'91 TDS 256KB RAM Card for the HP-48 SX

[Christoph Giesselink]

From my knowledge of the HP48 hardware, it's not possible to switch the banks of a RAM card > 128KB under software control with a HP48SX.

Only a HP48GX has a bank switcher logic for card slot 2, and only for the slot 2. This hardware logic adds 5 additional address lines for max. 2^5 = 32 banks. Slot 1 of the GX can only handle a 128KB RAM card like the SX.

So if somebody know, how this super duper 256KB RAM card is able to switch his banks under software control in a SX, please tell me. I'll try to implement this immediately into Emu48. ;-)

Christoph