PDP-11 architecture Was: internet blocking problem ?

Johnny Billquist bqt at update.uu.se
Fri Sep 11 10:31:51 CDT 2015

On 2015-09-11 17:28, Paul Koning wrote:
>> On Sep 11, 2015, at 11:23 AM, Warner Losh <imp at bsdimp.com> wrote:
>> On Fri, Sep 11, 2015 at 9:03 AM, Paul Koning <paulkoning at comcast.net> wrote:
>>> ...
>>> For efficient overlays, RT-11 with Link tends to be better.  It's less
>>> flexible but that reduced flexibility enforces more care in overlay design,
>>> and the implementation is a whole lot faster.
>> True. We were running under RSTS-E and so had some more flexibility.
>> However, by the time we got to this overlay structure, we knew we'd done
>> something horribly wrong and spent several weeks slimming down the program,
>> reducing the number of parameters to some routines and redesigning some
>> code to have either simpler algorithms, or inlining some code. We slimmed
>> it by 30% but more importantly went from about 8 overlay depth to 3. Still
>> slow, but it was acceptably slow rather than insane.
> The nice thing about RSTS/E is that you can use either the RT11 or the RSX tools, according to which is the best answer for what you're doing.  And that gives you a choice of overlay schemes (regions with LINK, or trees with TKB).

True. However, depending on which language they were using, that could 
limit them to just one or the other RTS. If your compiler generated code 
for RSX, you still could not use the RT-11 linker.


More information about the cctalk mailing list