🚀 go-pugleaf

bb16@prism.gatech.EDU (Scott Bostater) writes:

> I hope this doesn't sound too naive, but....
> 
> I have some software written for VMS version 4.6 that makes use of a PDP-11
> backward compatibility mode.  I want to run the software on a microvax.  Is
> this backward compatibility mode going to shoot me in the foot?  

Well, it depends how you define "shoot yourself in the foot".  If you
mean "will it work?", the answer is yes (you may need to purchase VAX
RSX; I'm not certain offhand if the emulation software is provided in
VMS or in the RSX kit).  Note I say "emulation" -- only VAX11/7xx and
VAX86xx machines have compatibility mode in hardware; others do it in
software.

In short, if you are using the PDP-11 compatibility mode instructions
extensively in compute intensive processing, you may suffer a serious
performance hit.  Otherwise, you might just get away with it.


Don Stokes, ZL2TNM  /  /                            Home: don@zl2tnm.gp.govt.nz
Systems Programmer /GP/ Government Printing Office  Work:        don@gp.govt.nz
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