m_thompson
Veteran Member
Tomorrow the RICM is moving the Lab to new+ space that is about twice the current size. That means that we can haul some more interesting items out of the warehouse and into the Lab. First on the list is the PDP-9 and the cabinet with the TC59 mag tape controller, and the TU20 7-track tape drive. Charles Lasner donated a TC02 DECtape controller, and we can borrow a very early design TU55 from the PDP-8/I.
The last time we ran the PDP-9 it would run the built in self test from microcode, so we know that lots of the processor is functional. It would also load a paper tape diag, which is also done from microcode. When we tried the memory checkerboard it went off into space. We can read/write memory, but doing that from the console doesn't mean it will work when the processor is running. Our plan is to try some very simple instructions to make sure that the processor can actually decode and execute instructions. If that works, we could try some more complex instructions like ISZ and JMP. If it is still working then we could try running the instruction tests from paper tape.
Once the processor is working again, we will connect the TC02 to the I/O bus and see how much of that works. We can repair and test the ancient TU55 on the PDP-8/I before we move it to the PDP-9 so we don't make debugging even more complex. If we can get the TC02/TU55 working we should be able to get a DECtape based OS running. That would be very cool.
The processor manual says that it has four data channels for devices like DECtape and magnetic tape., so it looks like we can connect both the TC02 and the TC59 without having a DM09, like you would need in a PDP-8. I wonder if we could hack the OS and run serialdisk?
We also need to rewind the sensor coil in the PC04 paper tape punch so we can get that working.
The last time we ran the PDP-9 it would run the built in self test from microcode, so we know that lots of the processor is functional. It would also load a paper tape diag, which is also done from microcode. When we tried the memory checkerboard it went off into space. We can read/write memory, but doing that from the console doesn't mean it will work when the processor is running. Our plan is to try some very simple instructions to make sure that the processor can actually decode and execute instructions. If that works, we could try some more complex instructions like ISZ and JMP. If it is still working then we could try running the instruction tests from paper tape.
Once the processor is working again, we will connect the TC02 to the I/O bus and see how much of that works. We can repair and test the ancient TU55 on the PDP-8/I before we move it to the PDP-9 so we don't make debugging even more complex. If we can get the TC02/TU55 working we should be able to get a DECtape based OS running. That would be very cool.
The processor manual says that it has four data channels for devices like DECtape and magnetic tape., so it looks like we can connect both the TC02 and the TC59 without having a DM09, like you would need in a PDP-8. I wonder if we could hack the OS and run serialdisk?
We also need to rewind the sensor coil in the PC04 paper tape punch so we can get that working.
