and we have stood in front of a
late-model PDP 1170 this end of it would
have had things like the memory box are
the storage and capacity expansion
things and then in this side was the
processor box the main processor box is
down underneath and with power supplies
right on the bottom and in the middle we
know it's a late-model PDP 1170 because
it doesn't have the nice switch panel
which the original ones modified so that
you could actually make you do things
manually yourself after that we have a
further expansion box and a strange tape
drive I suppose you would call it it
only accepted the smallest types that
were available so this is a small tape
typically it was used to load software
onto the machine the tape drive is
different to other there's no real at
the other end to put it on you simply
manually really dig around yourself and
you were ready to go as I say that were
fairly unique later other tape drives
are in the auto loan or they had a big
reel at the other side and they took
bigger tapes next we move on to the disc
storage within the computer this drives
in this era or typically a removable
pack that you insert it into the drive
so these are the two drives that are
attached to this PDP 1170 they each had
a capacity of 67 megabytes and they were
these later model
were much faster access than the earlier
models although that's all of relative
terminology my memory serves me
correctly the access time on these
drives was around a 30 millisecond mark
like this which was the base and then
you were ready to use your drive
spin it up to speed this is something
that we used to do a lot of a night as
we were doing copies for backup purposes
you would typically copy one disk to
another one swap the packs around take
your copy discount put the original disc
in swap the other disk and copy that
disk that way and this is a chore that
used to be split around people whereby
you know tonight it was my turn tomorrow
night somebody else did it we all had to
stay late on one time or another these
digital branded drives as on our mo3
they were really this driver control
data drive with a slightly different
case on and the digital badge and about
10,000 pounds added to the price other
than that there was absolutely no
difference whatsoever other
manufacturers used these drives and they
used them in quite a number of
capacities so fairly typically they
would most of the capacity changes were
done in software they were not they were
still capable of 67 megabytes but they
would do a little bit of sort of
fiddling around and restrict the
capacity and then they could come along
the engineer could spend all morning
with the covers off the drive and
upgrade you by just patching the
software and off you went
you didn't know that of course she paid
for his time on site beneath this we
have an RL o2 which was a 5 megabyte
drive again with removable pad
but you just clipped it in had a little
door that opened somewhere and when you
clicked it in and lifted the lid clip
back in and had a five megabyte
removable drive that would not have been
on a high-end machine like a 1170 that
would have been on a low-end machine and
later on still that we've got floppy
drives the floppy drives we all know and
love nowadays there's three and a half
inch floppy even those there umbrella 53
font then you have the five and a
quarter which was replaced by that in
this era we had an eight inch floppy
drive originally they held 80 K again
nice simple thing just like you do on
subscribes as this and you have to click
a Lister course modern ones you would
just put a floppy oh I say modern we
don't have you tried buying something
with a floppy drive on it nowadays and
you want 16 so that's the type of
storage options that were available in
those days the capacity is laughable
nowadays this was a large large drive at
67 megabytes
okay this is Tim Chamberlain again you
remember we loaded our mag tape onto the
funny little twiddly thing bit earlier
on on the pdp-11 70 this is a much more
modern tape drive if that's the correct
use of the term machi and we're just
going to load the tape onto this one as
a comparison so I open the door I post
the tape with a little reel and get
myself a little piece hanging out and I
press the load button when I can see it
there we go the load button and vacuum
sucks a tape in and you will hear
whooshing noises
it sucks the tape around the spindleswill notice it says it's loading
it's loaded the tape now and it's
running it backwards and forwards to
read the ID of the tape this to the
correct density and what type of tape it
is this was a brand-new tape so it has
no ID on it what would be interesting
now is we lift the lid will begin to
lock on it I'll power it off and then
we'll be able to lift the lid and you
can see how the loaded tape looks so
here it comes it's spun it all the way
around here it's used a vacuum system to
suck the tape all the way through around
this spool and then weld it on
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