[ih] "network unix"

[jack at 3kitty.org (Jack Haverty)]

Hi Noel,

You're right, I should have said 32KW....but I wonder how many people
today would know what "KW" means?  I suspect many would think it
referred to the power that our ancient monsters consumed...actually
probably not far off for the bigger machines that consumed many square
feet of lab space!

The other aspect of the "Stone Age" that may not be remembered today is
that a "byte" was not yet very well-defined back then.  PDP-8s had 8-bit
bytes in 16-bit words.  Other machines made different choices.  The
PDP-10 was agnostic -- the instruction set allowed the programmer to
specify whatever byte size they liked.  So a "byte" only made sense in
the context of a specific machine.

Today of course we all know that a byte is 8 bits.  Period.  Perhaps
some historian can figure out exactly when that happened.....

Fun times...
/Jack

On 10/09/2016 10:21 AM, Noel Chiappa wrote:
> A few notes/corrections:
> 
>     > The /40 design utilized a single address space for instructions and
>     > data, so everything had to fit in 32KB of memory (yes K, not M or G).
> 
> Err, that was 32KW, i.e. 64KB. But 8KB was the I/O page (device registers), so
> only 56KB of memory - sort of, because V6 Unix used one 8KB page to map in
> each process' kernel stack + other swappable per-process data, so really only
> 48KB for all kernel code, data, disk buffers, etc.