[HECnet] DU11 vs. DUV11

[Gregg Levine]

On Sun, Jan 6, 2013 at 1:20 PM, Bill Pechter <pechter at gmail.com> wrote:
perhaps rsx11s was planned for the pdt11 series.

On Jan 6, 2013 12:14 PM, "Lee Gleason" <lee.gleason at comcast.net> wrote:


              .IF DF   L$$SI1

              MOVB       @(R5)+,-(SP)       ;;; COPY CHARACTER FOR WORD MOVE
MOV         (SP)+,(R4)           ;;;   (SAVES 85 USECS ON PDT-11)

              .IFF       ; DF L$$SI1

              MOVB       @(R5)+,(R4)         ;;; OUTPUT A CHARACTER

              .ENDC     ; DF L$$SI1


OK, I'll bite.   Why is moving a character in the deferred location in
R5 to the stack and then, from the stack to the address in R4 faster
than just going from the deferred R5 location to the R4 address?

--

I'm even more curious what a PDT-11 optimization is doing in an RSX
driver...was there at one time an RSX product product planned for the PDT
family?

--
Lee K. Gleason N5ZMR
Control-G Consultants
lee.gleason at comcast.net

Hello!
I'm even more curious just what finally happened to that family
member. (And this week I'm not interested in finding one or two.)

-- 
-----
Gregg C Levine gregg.drwho8 at gmail.com
"This signature fought the Time Wars, time and again."