🚀 go-pugleaf

Rich Alderson <ne...@alderson.users.panix.com> wrote in
news:mddh8...@panix5.panix.com: 

> When introduced to the PDP-10, 8 years later, I found it annoying:  No
> base register, only a single index register per instruction, so some of
> my favorite tricks simply did not work.  No condition codes; what's
> with all these SKIPx and JUMPx and Txxx (test) instructions?  And then
> a miracle happened. 
> 
> I still think in EBCDIC, nearly 50 years later, rather than ASCII,
> which I sort of learned less than 40 years ago, and I still have a
> fondness for the 360 instruction architecture, but the orthogonality of
> the PDP-10 instruction set, the uniform use of bits 7-8 to indicate
> no-modification/immediate/memory/self on all the data movement
> instructions, the elegance of single instructions to conditionalize the
> execution path rather than a sequence in which you have to be careful
> of changes to the condition codes you're checking, even the word 
> addressing rather than byte addressing, have forever spoiled me for
> lesser systems.

I loved the -10 for its orthogonal instruction set.  It could be displayed 
on a single page of the programming card.  It didn't take long to learn.
I had started out on the IBM 1620, and then wrote extensively in assembler 
for the PDP-9 and when I came to the PDP-10 the family resemblance made it 
familiar but oh! so much better.

I never did much with the 360, but when I did, I was always having to look 
up instruction descriptions to understand what they actually did.  I never 
developed any affection for it.

The Data General Nova instruction set was (sort of) admirable for its cut-
down simplicity.  The DG Eclipse had to be admired for the way they added a 
lot of useful instructions, while still being 100% compatible with the Nova, 
but pretty it was not.  Even more so with the 32-bit MV series.

I did a little coding for the CDC 6xxx.  There were some clever things in 
that design, but I never thought it was elegant.