[Simh] Announcement: back10

[Johnny Eriksson]

Lars Brinkhoff <lars at nocrew.org> wrote:

> > But ok, such an encoding would work. But then your PDP-10 7-bit ASCII
> > files might not truly convert into 8-bit ASCII files... That final bit
> > can be a zero or a one... Some code on a PDP-10 did use that last bit
> > as well, when playing with 7-bit text, if I remember right.
> 
> That's right.  I understand some programs encoded a line number in a
> word with the final bit set.  But I would not call those pure text
> files.

Yes, a line number is stored as five digits, in a single 36-bit word,
with the low-order bit set.  This means that you will have to pad the
previous line with NULLs to get to a word boundary.  Example on how
this looks in emacs:

0180\260            DICTNEXT:           DCTNX^M
^@^@0190\260        DICTCLOSE:          DCTCL^M

--Johnny