[HECnet] Tops-20 ANONYMOUS FAL Preliminary Testing Results/DAP Query

[Thomas DeBellis]

Indeed; but there was a time when the PDP-11's 16 bit (64K) address 
space and eight register file seemed positively generous. That's when 
you compare it to the PDP-8's /single/ accumulator and 12 bit (4K) 
address space.

I continue to be astounded what they managed to do with that.  In 
addition to a nice package of languages, with a memory management unit 
(essentially a bank switcher), they got the thing to timeshare.  That's 
right; TSS-8.  There's one still running at the Computer History Museum 
on an 8/I.

So they got DECnet running on the PDP-8?  Wow.  I wonder how they did 
that; whether they re-targeted a BLISS compiler to emit PAL.  I remember 
looking at the source to PDP-8 VT (video) TECO.  Many awe most inspiring 
kludges.  What a tour de force. Very humbling.

The Algol compiler on the 20 has more than 2 bugs...  Sigh...

> ------------------------------------------------------------------------
> On 12/20/19 9:08 PM, Paul Koning wrote
> If you go far enough back, the space efficiency gets pretty amazing.  There's RSTS-11, which ran 16 timesharing users on a 28kW PDP-11/20. (Not well, but it ran.)  Or RT-11, quite comfortable in 8 kW and a 256 kbyte system disk.  Or DOS-11, which would even run, I think, in 4 kW.
>
> Somewhat earlier still, in 1961 two people implemented the first ever ALGOL compiler in 6 months, and it ran on a 4 kW machine (27 bit).  (It's known to have two bugs.)
>
> 	paul
>> ------------------------------------------------------------------------
>> On Dec 20, 2019, at 8:51 PM, Thomas DeBellis <tommytimesharing at gmail.com> wrote:
>> ...
>> But the mini-computer operating systems are just plain cool.  It is amazing what they squeezed into the PDP-8's 12 bit address space and PDP-11's run some of the most interesting collection of OS's that I've ever seen.
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