VCF-Berlin, 2015

Noel Chiappa jnc at
Thu Nov 5 10:00:23 CST 2015

    > From: Johnny Billquist

    > They could be from a PDP-11 or PDP-8 as well.

Not _impossible_ (since the RP11 does have one row of 36 lights - no doubt
because it can be used to read packs written by PDP-10's - it's the shift
register for reading the bit stream off the drive) but I'd say less likely,
given the two rows of 36 bits.

Or maybe not; one is a shift register, the other is a Longitudinal Parity
accumulator, which would also naturally be the same word length.

    > The RP11 controller, for example, I seem to remember had panels like
    > that.

In fact, I have a picture of an RP11 panel, and... the one in the back _is_
an RP11! Well, knock me over with a feather!

    > Can't recall any PDP-8 stuff at the moment, but I'm pretty sure I've
    > seen something like that for a PDP-8 as well.

I've seen images of (or worked out the light pattern for) two, the TS08 and
the RK08, and this isn't either one. (Both have only two rows of lights.)
I wonder if there's an RP08? {Checks} Yes, there is. Do we have prints?
{Checks} Yes. Alas, the scans of the connector pages of the prints are
pretty bad, but it doesn't seem to support a display panel.

    > From: Vincent Slyngstad

    > A higher resolution  picture

Oooh, thanks very much, that will be _very_ helpful.

    > From: Al Kossow

    > They are both disk controller panels.
    > The one marked tape controller has "sector word count"

Hmm. Could be; now that I have the better picture, let me see what I can
turn up.

I note the 'sector word count' has 7 bits in it, which kind of implies a
PDP-10 - most PDP-11 disks had 512 bytes / 256 words -> 8 bits. Although
maybe there are a few early ones that had 256 byte sectors, I have this vague
bit set that there were; will have to check that.

I think I'm going to have to create a page for DEC indicator pabels!


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