30 Aug
2006
30 Aug
'06
1:35 p.m.
An obscure unibus & pdp-11 question:
Does "clr" always do a DATIP (i.e. read-modify-write) on all 11's?
It does on my 11/44. Something tells me I've seen threads (long ago) on
this and the perils of using clr as opposed to "mov #0," when talking to
hardware.
The rl01 bootstrap does it talking to rl11 registers, which tripped me
up for a bit.
-brad