19 Feb
2025
19 Feb
'25
3:39 p.m.
On 2/19/25 17:38, Chuck Guzis via cctalk wrote:
It uses the RJ instruction to record register content, bit-by-bit.
Think about it--RJ is about the only instruction that can modify memory
without fiddling with the A6 and A7 registers.
Of course... I vaguely recalled there was a bit-by-bit save, but didn't
think of the RJ. Thanks.
Gary
One of most ingenious coding tricks to me was the
problem of saving and
restoring all registers without resorting to an exchange jump. We used
that one as a test for applicants.
Argh... I know I've seen this trick, but it's been too many years. How
about a hint?