Old HP48SX resurection and upgrade

[manjo]

(02-19-2019 02:12 PM)rprosperi Wrote:  Keep in mind that if you wire the additional RAM as Port-1, you can then merge that 'Port RAM' into main RAM, achieving the same basic thing as your original goal, assuming you don't plan to use Port-1 for a real card.

As a matter of fact I wired it to pins closer to RAM and ROM chip, it turned out that those are PORT2, PORT2 MERGED with IRAM as expected:
2 MERGE
and that's it...

Interesting thing is that, in some places ports are refered to as Port-0 and Port-1, on other places PORT1 and PORT2...go figure...
It seams .. I was just lucky...