Re: Will Digital's abandonned software ever go "public" ?

phil_at_rephil.org
Date: 11/11/05 

Date: 10 Nov 2005 21:53:03 -0800

Bill Gunshannon wrote:
> In article <890539d90511031104m64b98fd8t190fe4bae9b47414@mail.gmail.com>,
> Carl Friedberg <frida.fried@gmail.com> writes:
> > I seem to remember this was where I first heard the term "Cutler
> > coding". It referred (to DNC, of course) to Dave's abhorrence of any
> > wasted locations -- he would dig around for an instruction which
> > had the right value to use as a constant...
>
> This was more common than you might think, especially in the early
> microcomputer days (remember, 28K Words is not much memory).

<SNIP>

> JMPing into the middle of the address saved the programmer
> one byte of memory.

I'm a day late and a dollar short, but while it was certainly more
common, Cutler was absolutely brutal about it. He came over from
DuPont to do RSX-11M, the small memory version of RSX, and he inspected
*every* line of code in the system. If he could write it smaller, you
got it returned. (He had a stamp that said, "Size is the Goal," but I
wouldn't be surprised if the slightly more risque version -- that his
stamp said "Size Matters" -- were true.)

My father, who wrote the -11M error-logging subsystem, is really proud
(to this day!) about the fact that he was able to successfully argue
his case when he wanted to use two *BITS* that Cutler didn't think were
needed, until he heard the proposal.

No; there is not a lot of unnecessary repetition in RSX-11M! (perhaps
-11D, probably -11A)

Incidentally, I think that coding this tight is one thing that makes
for the reliability of RSX and VMS, and my personal bias is to suggest
that just becuase memory's cheap doesn't mean that coding should
necessariy be approached any differently -- but that's just (my)
armchair philosophy.

Cheers,
Phil Mendelsohn

Relevant Pages

  • Re: Basic ASCII File Reading
    ... (snip on programs relying on all available memory in blank COMMON) ... but the one in BLOCK DATA ... Many of the tricks used to divide up one large array at run ...
    (comp.lang.fortran)
  • Re: How to release memory ?
    ... how do perl developers handle quite commons tasks where one program needs ... Reuse the space yourself, commonly by using a $global to hold the data. ... So it is common in Perl programs, to see the system memory usage rise to ... It is common to use disk-based databases to handle sharing of huge data. ...
    (comp.lang.perl.misc)
  • Re: MPM bring up.
    ... Even if you build a MP/M kernel without any RSP's, ... The 16KB common are comfortable to work with, ... What if the banks are in a linear memory ... that the disk system can address directly. ...
    (comp.os.cpm)
  • Re: MPM bring up.
    ... You can't use more memory than the ... smallest possible common segment allows, and you won't get it down to 4KB, ... The major complaint with MP/M always was ... tracks on a disk. ...
    (comp.os.cpm)
  • Re: A question about memory bank switching
    ... 16KB common and 48KB TPA left. ... may specify their memory management schemes. ... One can cheat a bit on switched banks of memory, ...
    (comp.os.cpm)