🚀 go-pugleaf

On 2018-07-14 16:45, John Levine wrote:
> In article <picc8e$360$2...@dont-email.me> you write:
>> One tended to be overawed by the PDP10 series, but I wonder if
>> its operating systems would seem rather infra dig compared to Linux
>> today?
> 
> In terms of number of features, linux wins by a parsec.

Not so sure. If we talk about the OS as such, there are a couple of 
things Linux has that TOPS-20 don't. But that is true in the other 
direction as well.

Now, if you instead were to talk about useful applications, then sure, 
Linux have way more of that.

> In terms of getting useful work out of a computer that ran at about
> 5MHz (yes, I know the KA was async) and had 1MB of core, TOPS-10 wins
> just as much.  It had features that mattered then but don't any more
> like doing disk I/O directly in and out of buffers in user space
> without an extra copy.  I could have done without the sequence numbers
> with the flag in the low bit of the word, though.

Disk directly to buffers in user space in Linux? Sure, it's called mmap. 
Which, by the way, is more or less a direct ripoff from TOPS-20.

> Of course, even TOPS-10 was a pig compared to DTSS which ran on a GE
> 635, about the same speed as a KA-10, with a very slow front end
> terminal mux (sort of like a 680) and provided good performance to 100
> users.

One of the more interesting features I remember from Tops-10 was that 
you could have a daemon that kicked in when files were accessed that you 
did not have access rights to. And that went though a script, which 
could modify the rules for access to the file arbitrarily. I remember it 
being very cool, and I don't know of anything similar today.

   Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: b...@softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol