10 Apr
2026
10 Apr
'26
3:18 p.m.
On 10/04/2026 05.30, Terri Kennedy wrote:
On 2026-04-09 09:24, Dave McGuire wrote:
I know (heard) that CIS would be used for copying memory around, but
what in the kernel would depend on FPP?
(A little surprising is that RSX don't, however, it will use the block
move instruction of the Mentec processors that have that one.)
In RSX, it only is a topic for context switching and trap handling. The
kernel don't depend on the actual behavior more than in the most basic
sense otherwise (auto increment/decrement being done with the right
amounts, and only the actual registers referred to being changed when
expected, and so on.
/me slaps forehead
The 11/70's FP board set is flaky, and it has been removed pending
repair. I had forgotten about that. But the "hello world" program
shouldn't use any FP instructions..?
Be careful with bad FP and modern(ish) RSTS/E. It will use FP
(and CIS, for that matter) in the monitor, and if your boards are
returning garbage, you can scarfle* your system disk. * Bonus points for anyone who knows what scarfle
means. It's ac-
tually SCRFLE and is a boot command on MAI Basic-4 systems which
erases the system disk you booted from.
Never heard that one. :-)
Johnny