We don't have any PDP-9 I/O cables. These are a block of 4x flipchips so you only need 2x BC09 I/O cables. The BC09 cables are nearly identical to the BC10 I/O cables for the KA10. The LCM has lots of those, but isn't willing to part with any.
For now we are using 8x PDP-8 I/O cables. This works OK, but is a little more complicated to wire. We don't have a second set of 8x PDP-8 I/O cables to connect from the TC02 DECtape controller to the TC59 Magnetic Tape controller. I will probably try using a set of Vincent's ribbon cable FlipChips to see if those will work OK.
We also need 3x cables that connect to the indicator lamps on the TC02. These are direct finger to ribbon cable on one end and finger to ribbon cable through a diode on the other end. I will work out with Vincent what we can use, and if we need to reproduce one of the FlipChips.
On Saturday we disconnected the TC02 and connected the TC59. The TC59 has a feature where you can read/write the Data Register and then force a Data-Break. One of the diagnostics tests the Data-Break feature so we could use this to determine if the Data-Break problem is in the TC02 or the processor. The first test verifies that all possible combinations of the Command Register can be read/written, and that worked OK. The second test verifies that all possible combinations of the Data Register can be read/written. That one failed. We haven't used the TC59 for a few years, so that is not surprising.
We toggled in some little programs to fiddle with the Data Register, and were surprised at the behavior. The TC59 has both inputs on the Data Register flipflops wired to the I/O bus, so a 1 on the I/O bus compliments the data in the Data Register. This seems pretty complicated, so I wanted to look at the code in the diagnostic. Unfortunately the printed manual and listing for the diagnostic are an early version, and the only image of the diagnostic that we actually have is a later one that works for both the PDP-9 and the PDP-15. I am working on a paper tape disassembler to get a source listing from the paper tape image. Then I can see if I can pull comments from the earlier listing to make a working new listing.
In the middle of testing with the TC59 the I/O got flakey. The processor will run Instruction Test 1, but fails on Instruction Test 2 where it is testing the line clock. It looks like we need to fix some more things in the I/O section of the processor.