PDP-8 Straight 8 restoration

Marc Howard cramcram at gmail.com
Sun Mar 29 17:11:24 CDT 2020


Nigel,

I first learned assembly on a straight-8.  Also learned about repair with
the same machine (1974).

As for fun time wasters back then there was a DECUS paper tape that could
compute n! up to 200! exactly.  I remember that I could start it before
lunch, come back, and then about 15 minutes later it would start printing
all the digits for 200!.

Enjoy your 8,

Marc Howard


On Sun, Mar 29, 2020 at 2:59 PM Nigel Johnson via cctalk <
cctalk at classiccmp.org> 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.
>
> 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.
>
> 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!
>
> 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!
>
> 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
>
>
>
>


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