Re: C64 ROMs on a MAX?

From: MagerValp (
Date: 2001-02-08 13:16:35

>>>>> "RB" == Ruud Baltissen <> writes:

RB> If the Max has only one CIA, at what address does it show up? The
RB> C64 has two CIA's. Remove the "keyboard"-CIA, and you have no
RB> interrupt: cursor does not blink. Remove the "drive"-CIA and you
RB> have no normal screen as this CIA steers two lines of the VIC.

RB> Presume the CIA of the MAX is the "drive"-CIA and the rest of the
RB> hardware (addresses and wiring) is the same, you only have to
RB> "move" the interrupt by replacing the addresses of the used timer
RB> by the ones of the "drive"-CIA.

I'm pretty sure the MAX has the $dc00 CIA but not the $dd00 CIA -- the
VIC address lines are just kept low, as it can only address 16K of
RAM. The rest of the stuff in the $dd00 CIA is useless in a MAX as it
doesn't have a serial or a user port.

    ___          .     .  .         .       . +  .         .      o   
  _|___|_   +   .  +     .     +         .   .  Per Olofsson, konstnär
    o-o    .      .     .   o         +
     -       +            +    .
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