the key character was the "S" - that stood for serial - the later PDP-8 computers worked 8 bits in parallel, but this one was serial - it was a basket case when I got it, one christmas vacation I brought a storage scope home, and when I finally decided to ignore the poorly worded instructions and adjust the way logic told me the timing had to be, I got the core memory working. There was a board called a "rectifying slicer" that did the work, and you had to adjust when to sample the read line compared to the address pulse. Anyway, after relpacing several hundred parts (mostly diodes and transistors), and getting the core adjusted and working, I then discovered that the instruction decoder didn't work - but the vacation was over. I sold it, broke even, and bought an AIM-65 (I'll bet at least one other person remembers the AIM 65)