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    Restoring a PDP-8/L

    I have restored a PDP8/L, its about 10 years now. I did this litte web-page to easier find my way around the schematics for the modules: http://www.pdp-9.net/docs/pdp-8-l/modules/index.html
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    PDP-9 at the RICM

    Sure, I realized that there are no pull up/down resistor to measure the current thru. This is also not the version that matches the board. I'll do more changes...
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    PDP-9 at the RICM

    I have made this so far. A prototype of a levelshifter, to 3.3V logical levels. Two channels of I/O. Tolerant to +/-15V in case of faulty modules. Releays are for galvanic isolation. Three holes in top is ground and connections to the pins of the tested board for clipping on oscilloscope probes...
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    PDP-9 at the RICM

    Which components fails usually? How do they fail? I'm trying to understand what a tester must be able to find.
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    Change bearings in RL01 drive?

    Is there someone here that has changed bearings in a RL01 drive? The bearings in the disc spindle in one of my drives sounds bad and generates vibrations. From what I can see the belt pully is pressed on the axis. I guees heat, a puller and a hydralic press is good tools to have. It seams like...
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    A new G888 manchester read/write module

    Roland Huisman solved the problem with the RK05 to RK8E cable, which is great (which is the one I use, thanks Roland). I'm trying to do the same for TD8E to TU56 (and even TU55) cable. I have drawn replacement boards for M961 and M960. The "M961" board also includes the five G888's. The...
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    RK05 problems

    I had my RK05 working, but now it wan't pass the MAINDECS anymore. It fails the "drive control test" at address 3277: http://svn.so-much-stuff.com/svn/trunk/pdp8/src/maindec/08/dhrkb-e-d.pdf As I understand it all data written to the disk and is verified in the test before. The test that fails...
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    Hacking a bit with spacewar without EAE, detailed info about AX08 programming wanted.

    0 Fire (Red) 1 Rotate L 2 Rotate R 3 Thrust (Green) 4 Yellow 7 Yellow 8 Fire (Red) 9 Rotate L 10 Rotate R 11 Thrust (Green) My idea was to change the code so that the yellow triggered hyper space, but I never came to it. In the implementation I have hyper space is triggered by pushing both...
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    Looking for an omnibus extender board

    I found some proper DEC connectors so I ordered a custom board. No hard gold unfortunately, so lets see how long it will last.
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    New limited function board for PDP8a with MOS memory

    Well, what should I say? THANKS! Finally I got something to print on the 3D-printer at work. An Ultimaker 2+ for those that might be interested.
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    New limited function board for PDP8a with MOS memory

    A friend of mine got parts to build a small PDP-8a/100 with MOS memory. After some time he figured out that the limited function panel didn't work, it was for a core memory machine! I draw a new one, it should be possible to move the components from a core-board to this new one. I built mine...
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    Questions About the TU56 Tape Drive

    I used those: https://eu.mouser.com/ProductDetail/80-R60EW61005000K 100uF/100V I should really print some holders to those...
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    Looking for an omnibus extender board

    I'm looking for an omnibus extension board or flexible top connectors. I want to get access to the component side of the middle board of a RK8E board set (M7105). Either I need to put two boards on extenders (have one) or I'll need top connectors with a flat cable in between the connectors (have...
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    What is DB08?

    I found this backplane in a box. I know what a DB08-E is, but is this something similar? For which 8-series computer was this used? I tried to find something on bitsavers on it but didn't succeed.
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    RK05 fan blower motor

    The motor turned very nice and easy! You can see the black in the middle of the picture, this is a burned winding.
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    RK05 fan blower motor

    I'm restoring a RK05 drive, but have a problem with the fan. It rotates, but really slow. The motor capacitor is fine. The motor gets crazy hot, over 100 degrees Celsius within minutes. I have opened up the motor and its has at least one burned winding. The fan assembly is this one...
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    Dec RK8E controller for RK05 wanted

    Nice! Well, I built your board but I haven't tested it yet. I'm waiting for a spare part to the power supply in my drive. So I'm a few steps behind. Here's a picture of the board...
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    A new G888 manchester read/write module

    Well, this is something I have been struggling with for almost four years! The history starts in 2014 when I was given a PDP-9 computer. Almost immediately I realized that the paper tapes and magnetic tapes must be preserved. I also realized that I had a long way to go if I would use the PDP-9...
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    BC08H Cables

    Ok, the cables are tested in together with my homebrewed expansion box. Works OK! It's built from a PDP-8a/100 chassis with a 10-slot backplane. I had no regulator board for this so it's equipped with modern switch mode power supplies for 5V +15 and -15V (no new holes drilled). I had to build a...
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    Document scanning

    After having been introduced to Vince MAINDEC archive (http://www.vcfed.org/forum/showthread.php?63733-Dec-RK8E-controller-for-RK05-wanted&p=536702#post536702) I started to invent my PDP-8 paper tapes and documentation. There are some items that needs to be scanned and some paper tapes to be...