youtube video of a runnning XDS Sigma mainframe with lots of nice peripherals

Diane Bruce db at
Sat Oct 31 16:05:26 CDT 2015

On Sat, Oct 31, 2015 at 06:51:18PM +0000, 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.

oops. Sorry yes, this is exactly what I did. Dropped my own address into
and executed code I stuffed in at run time into a data variable.
That needed a compile flag to link the data as executable. (I think)

> * On the ICL1900 all assignable labels got small integers which were used as an
> index lookup in an assigned goto thus that trick would not work.
Ah pity!

- db at db at

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