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List:       classiccmp
Subject:    Re: youtube video of a runnning XDS Sigma mainframe with lots of nice peripherals
From:       Chuck Guzis <cclist () sydex ! com>
Date:       2015-10-31 21:08:32
Message-ID: 56352DD0.7080306 () sydex ! com
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On 10/31/2015 11:51 AM, ANDY HOLT wrote:
>> I remember hacking the computed goto in the Fortran so it would
>> execute my own entered assembler. That was fun. ;)
>
> Interesting - it was a more normal hack to abuse the assigned goto -
> in most implementations* the variable contents were just a genuine
> memory address and you could drop code into a common block thus Bob's
> yer uncle.

Absolutely.  The ASSIGNed GOTO was subject to much abuse--in CDC's 
FORTRAN compiler (FTN and RUN) the COMMON and EQUIVALENCE sanity 
checking routine was a very large set of ASSIGNed GOTOs to implement a 
state machine...with absolutely no commenting at all.

It was one of those "don't fool with this thing as you'll probably end 
up breaking it"  routines.  I've seen others over the years--they do 
what they're supposed to do, with incredibly complex uncommented code.

It's probably a good think that X3 eventually dropped ASSIGNed GOTOs 
from the language.

--Chuck




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