PDP-8 Straight 8 restoration

Warner Losh imp at bsdimp.com
Sun Mar 29 18:33:35 CDT 2020


On Sun, Mar 29, 2020, 5:10 PM Diane Bruce via cctalk <cctalk at classiccmp.org>
wrote:

> On Sun, Mar 29, 2020 at 05:59:42PM -0400, Nigel Johnson via cctalk wrote:
> > Brings back memories!  My first 6800 cross assembler came to me as 2000
> > Fortran source code punch cards. We had an F4R4 compiler on the PDP11 but
> > the card reader was on the PDP-8.
>
> Funny how the kids don't realise Fortran was the 'C' language at one time.
> Editors, linker, macro preprocessors a lot of it was done in Fortran. ;)
>

He was lucky the card deck was in order. One of my first jobs was to read
in old, horrible FORTRAN IV from punch card, then check it against a
listing the boss had and edit to match... This was the same place we wrote
malloc for FORTRAN and passed around all kinds of crazy data structures
that offset into the malloc arena so it would run on both the pdp-11 and
the vax...

Warner

>
> > The only common peripheral was paper tape.  One night, the Chief Engineer
> > and I fed the cards into the PDP8 card reader, punched tape, and fed it
> > directly into the PDP11 tape reader.  X-on X-off was handled by hitting
> the
> > stop and continue buttons on the PDP8 as the punch was faster than the
> > reader.  The buffer was a pile of paper tape in the floor, which we
> > carefully prevented from tangling.  Somehow OS/8 managed to not crash
> with
> > the constant start/stop.
>
> heh I can only imagine.
>
> >
> > Nobody was more surprised than we were when the output compiled
> perfectly on
> > the PDP11 and we made our first 6800 program - a ham repeater controller!
>
> Cool!
>
> >
> > The Chief Engineer is still alive - I was at his 95th birthday last year
> and
> > we often have fun talking about the good old days!
>
> Nice!
>
>
> >
> > cheers,
> >
> > Nigel Johnson
> >
> >
> > On 29/03/2020 16:59, Diane Bruce via cctalk wrote:
> > > On Mon, Mar 30, 2020 at 09:47:51AM +1300, Brendan McNeill via cctech
> wrote:
> > > > Here in NZ and around the world many of us are in lockdown and
> spending more time on our computers, if that were possible.  I have just
> completed the restoration of a PDP-8 Straight 8 which I believe is the only
> one in New Zealand.  You can view the restoration story and find
> appropriate resources here:  https://pdp-8.nz <https://pdp-8.nz/>
> > > >
> > > > While it plays Chess, it would be great if someone wanted to write
> (say) a Prime Number Generator, or some other application and email it to
> me off list.  I have Focal-69 and can probably source other languages for
> this wonderful old machine with 4K of memory.
> > > I have memories of keying in RIM and BIN. Long long time ago. I also
> learned
> > > how to talk to the OS/8 file system so we could play morse code from a
> file
> > > instead of a paper tape for our University club station. ;)
> > >
> > > > --------------//----------------
> > > > brendan at mcneill.co.nz
> > > > +64 21 881 883
> > > >
> > > >
> > > >
> > > >
> > > 73 de VA3DB for those that care ;)
> >
> >
> > --
> > Nigel Johnson
> > MSc., MIEEE
> > VE3ID/G4AJQ/VA3MCU
> >
> > Amateur Radio, the origin of the open-source concept!
> >
> >
> > You can reach me by voice on Skype:  TILBURY2591
> >
> > If time travel ever will be possible, it already is. Ask me again
> yesterday
> >
> > This e-mail is not and cannot, by its nature, be confidential. En route
> from me to you, it will pass across the public Internet, easily readable by
> any number of system administrators along the way.
> >    Nigel Johnson <nw.johnson at ieee.org>
> >
> > Please consider the environment when deciding if you really need to
> print this message
> >
> >
>
> --
> - db at FreeBSD.org db at db.net http://www.db.net/~db
>


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