[TUHS] mental architecture models, Anyone ever heard of teaching a case study of Initial Unix?

[Charles H Sauer (he/him)]

On 7/6/2024 3:56 PM, John R Levine wrote:
> On Sat, 6 Jul 2024, Clem Cole wrote:
>> ESPOL predators all of them, although one can say since it was only
>> available on Burroughs large, medium, and small systems - it was 
>> retargeted,
>> but not widely used.
> 
> Good point.
> 
>> Other systems programming languages followed, BCPL, BLISS, PL/360 and 
>> even
>> B before C. If you consider PL/M a child of PL/360 (which is was more 
>> than
>> child of PL/1 if you look at it), all of the others have code generators
>> and libraries for multiple ISA and OS and did before C did. That said, I
>> don't think any fo them have as many targets as C and many FORTRAN.
> 
> Untangling the sequence of all this stuff is hard.  BCPL was indeed 
> retargeted at a lot of machines but it's not clear how portable programs 
> were since the word sizes varied so much from 16 to 60 bits, but 
> couldn't deal with byte addressed memory which is a large reason we have C.
> 
> The original version of BLISS was only for the PDP-10.  DEC retargeted 
> it to the PDP-11 and VAX, but I think that was after Unix moved to the 
> Interdata and possibly other machines.
> 
> PL360 was Wirth's implentation language for Algol W, a 360 assembler 
> with Algol-like syntax that had nothing to do with PL/I and only 
> targeted the 360.  I used it, it was pretty nice.
> 
> Are you maybe thinking of IBM's PL.8 or PL/S?  The former was originally 
> for the 801, later S/360 and ROMP, the latter used for S/360 system 
> programming.  PL.8 was about 80% of PL.I, hence the name, PL/S a subset 
> with some hackery like register declarations and in-line assembler.
> 
> R's,
> John

I like the 80% explanation, but suspect PL.8 was really named PL.8 to go 
along with the 801 processor architecture defined in Building 801 aka 
Thomas J. Watson Research Center in Yorktown Heights. There are probably 
living Yorktown alumni that could be definitive.

I found PL/I quite usable as long as one kept it simple. But then, I 
also found Fortran usable as long as one kept it simple. Regarding 
Fortran portability, I did all my dissertation work on punched cards 
using CDC Fortran on the 6400/6600 at the UT-Austin computation center. 
I brought several boxes of cards to Yorktown and don't remember any 
significant difficulty getting my simulator and other programs to run on 
VM/370 there. The absence of pointers and structures in Fortran was 
annoying. Eventually I used SNOBOL to quickly translate the Fortran to 
PL/I (https://technologists.com/sauer/RESQPPP.pdf).

Charlie

-- 
voice: +1.512.784.7526       e-mail: sauer at technologists.com
fax: +1.512.346.5240         Web: https://technologists.com/sauer/
Facebook/Google/LinkedIn/Twitter: CharlesHSauer