> -----Original Message-----
> From: Jon Elson via cctalk <[email protected]>
> Sent: 08 October 2022 03:10
> To: ben via cctalk <[email protected]>
> Cc: Jon Elson <[email protected]>
> Subject: [cctalk] Re: Bendix G-15 Restoration
>
> On 10/7/22 18:14, ben via cctalk wrote:
> > On 2022-10-07 1:09 p.m., paul.kimpel--- via cctalk wrote:
> >> We'd all like to see the ALGO compiler, but be forewarned
> >> -- it's something like 14 passes on paper tape, with intermediate
> >> results punched on paper tape. I understand it's a bit more
> >> convenient to use if you have magnetic tape drives, but it's still
> >> going to be slow -- there's only so much you can do with 2K words of
> >> memory.
> >
> > Trying to hide the fact the drum makes it slow.
> > Did any one ever replace the drum with core memory, on the early
> > serial computers?
> > Ben.
> >
> Tghe G-15 was a serial computer with an 90 KHz bit clock. The entire
> organization of teh computer revolved around the drum (pun intended). There
> was an optimizer that organized instructions around the drum so that the next
> instruction came up on the read head just as the last instruction
> finished. Without tearing the entire machine apart and redesigning the logic,
> core would not make it faster.
>
I know the Ferranti Pegasus which is/was a serial machine everything was
clocked to the drum. If the drum failed there was a special set of hardware to
re-write the clock track.
Whilst replacing the clock would not have been hard, I don't think adding core
would have helped there because everything was so integrated.
.. it used delay lines for registers which ran at the same speed so everything
just worked...
> The PDP-8S did have core memory, and for a bit serial computer, it was fairly
> fast.
>
For calculation, I believe the G-15 was fast. I can't believe any one would
seriously run a high level compiler on such a machine.
> Jon
Dave
