M220B (PDP-8/I) schematics available

From: Bob Shannon <bshannon_at_tiac.net>
Date: Thu Jul 10 18:06:01 2003

Hell yes, the blinkinlights are over half the point to vintage hardware!

When I built my HP1000 ATAPI (IDE) disk controller, the first job was
drilling 72 holes in the rack
mount front pannel for the LED's!

Turning that into a working disk drive was rather, well, secondary to
getting the LEDs blinking in a meaningful
way. I even tweaked my current limiting resistors to try to match the
LEDs brightness to those of the HP 2113
CPU, and use a real HP grey blank panel spacer so it would look 'close
to right'.

I gotta get .JPG of that machine on-line someplace....

Tony Duell wrote:

>>One of these days, I need to get my RK11-C up and working (I have a
>>working RK11D that's been used recently - I've had the -C since 1984
>>and haven't ever had the occasion to power it on).
>>
>>I should probably build a KM-11 clone first.
>>
>
>You'll need it. Actually, it's useful to have _2_ of them, since there
>are a pair of KN11 connectors with different signals on them.
>
>Does anyone have the full lights panel for the RK11C? It's 144 LEDs or
>bulbs that display the I/O registers, etc. I have the panel, but not the
>right bezel for the RK11-C (I only have the DX11 bezel...)
>
>Not particularly useful, but the blinkenlights sure look pretty....
>
>-tony
Received on Thu Jul 10 2003 - 18:06:01 BST