So, the Commodore 64 has two special registers in locations $00 and $01. By writing to these registers, you can somehow turn on and off the ROMs and other things. The thing that I am not understanding is why there is a direction register at location $00.
So if you write a 1 or 0 to the first bit in location $01, somehow this controls whether you can read from Commodore BASIC ROM or from RAM at the same addresses (in the literature this is apparently known as the LORAM
signal). And I'm interested in knowing what happens if you write a particular value to the same bit in location $00. Does that mean that LORAM
is now an input? Can you use this to test if BASIC is on?
how does it work
, I think it effectively askswhat is it
(whereit
is the mechanism for accessing memory), and that feels slightly awkward to read (in UK English at least).