On Sep 7, 2023, at 9:12 AM, Paul Koning via cctalk
<cctalk(a)classiccmp.org> wrote:
On Sep 7, 2023, at 3:17 AM, Lars Brinkhoff
<lars(a)nocrew.org> wrote:
Paul Koning wrote:
Even then it increments by 2, by special
exception. So 112700, 1
(movb #1,r0) fetches the instruction and increments PC by 2, then
fetches the word where the PC points and increments by 2, not 1,
again.
It's not really a special exception because immediate mode is @(R7)+.
(R7)+, actually; @(R7)+ is absolute. I meant "special exception" because auto
inc/dec of R6 and R7 always increments by 1, while for R0-R5 it increments by the datum
size.
Oops, typo. Of course, auto inc/dec of R6 and R7 (SP and PC) always increment by TWO,
while auto inc/dec of other registers increments by the size of whatever is accessed.
paul