Classic, Woodstock and Spice Emulators

[PANAMATIK]

(08-03-2016 04:18 PM)Harald Wrote:  Wow, there is really a lot happening in terms of emulators these days! Thanks Bernhard!

Harald,

In this case, you are 4/5 responsible for making this possible, because 4k out of 5k ROM I could extract from your HP-19C, which you gave me some month ago for this purpose. I needed until now to understand how the 5th k could be read: Two of the ROM chips in the HP-19C have dedicated chip select inputs, one is low active, the other high active, sharing the same address space at 4k. The chip select pin is controlled by the s0 bit in the ACT status register, which is connected to the two ROMs. In later calculator models i.e. HP-67 HP invented the bank switch instruction, which toggled between the ROM chips during runtime without needing an extra chip select pin.

Many credits! Thanks again for your help, you will be mentioned in the upcoming manual of the HP-19C emulator.

Bernhard