[U2] EXECUTE vs PQN (was: D3 Master Dictionary)

[Clifton Oliver]

EXECUTE was invented at Devcom by John Drumheller. Part of the idea was 
to have INFORMATION be a one-language machine. Paragraphs were 
introduced because some Neanderthal VAR swore they would sell many 
machines if they didn't have to compile programs for batch jobs. So 
Bill Wilson coded the first paragraph processor. It was a simple "start 
at line 2, REMOVE each line and EXECUTE it." Of course, no good deed 
goes unpunished, so in-line prompts, looping, and a 
forward-reference-only goto followed. The original team hated 
paragraphs, but you've got to eat. One of the Snake Pit's mottos was 
"PROCs are Crocks!"

Now in fairness to MCD, Rod Burns, who was a former MCD engineer, 
pointed out that Don Nelson's machine had been spec'd to completeness. 
That is, the code realization of it had the built in issue of the 
original design not being open ended. Thus, implementing things like 
EXECUTE layers was a Non Trivial Task. Every bit in that PCB was 
used--three or four times, as any PICK Assembler programmer will tell 
you.

Similar issues hindered the PICK world's implementation of B 
correlatives as a response to INFORMATION's I-descriptors and SUBR 
function.

Life is much easier when you write your own run-machine from scratch. 
Of course, you risk starving in the process. :-)

--

Regards,

Clif

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
W. Clifton Oliver, CCP
CLIFTON OLIVER & ASSOCIATES
Tel: +1 619 460 5678    Web: www.oliver.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
On May 7, 2004, at 21:08, Mark Johnson wrote:

Everyone else focused on EXECUTE/PERFORM while MCD developed the PQN to
handle some of these advanced features. Now, writing procs is a lost 
art.
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