RX02 Drives are working! Say hello to RT-11

Dave popped round yesterday so we could try his RX02 drive in my PDP-11, which worked, which meant the controller he had sent me definitely works. We had a play for a bit and once he left I tried the RT-11 floppies in my own RX02 drive hooked up to my PDP-11. To my amazement, the thing booted! Here is me and Tom trying to figure out how Chess, even after reading the manual:

So, let me try and explain why I came to the conclusion my drive wasn't working, when it fact, it mostly and probably was.

• Initially I tried dumping floppies over serial using VTserver and it would just fail. VTserver is pretty commonly used, so why wouldn't it be working if there was not a problem somewhere else?
• I booted into XXDP using tu58em and ran the diagnostics, all of which failed. Why would DEC's diagnostics fail if they were working?
• Marc came over and we had a play. After feeling sorry for ourselves we apathetically looked down at the RX02 R/W board and saw a piece of metal lying across several tracks and an AND gate.
• We ran the XXDP logic diagnostics and it passed, having previously failed every test just before we removed that stray wire. At this point I was pretty sure the controller was fine so tried dumping a floppy again with VTserver. Again, it failed, but the error register had a different value.
• I try booting from pretty much every floppy I have, and even the ones labelled RT-11 wouldn't boot.
• Finally, Dave, my saviour, comes over and I am now able to boot into RT-11. I check all of my floppies with DIR DY1: and see that 10 out of my 12 are working, but none of them contain RT-11. Don't trust the labels, people.

So it was a combination of, A) having no boot disks, B) VTserver not working for some reason and C) a random piece of wire lying across the board.

I want to boot into LSX UNIX (a compressed v7 for RX02 floppies), but VTserver does not work, so I am not sure how I can make a floppy. I might try PDP11GUI, since it appears to be working under Wine.

There is still plenty to be done. I still don't have my RL02 drives working, and there could be a number of issues with that:

• VTserver might not be working for RL02 drives either and so I am unable to dump the contents.
• The RL02 packs might not be initialised for RT-11 so I can't see whats on them. Additionally, I don't think RT-11 can initialise RL02 packs for some reason.
• There could be something wrong with the drive.
• There could be something wrong with the controller.

Still, I am making progress and having fun along the way. My eventual setup will hopefully be something like this:

• 2.11BSD
• 1MB of RAM, plus an extra 128K from the MXV11 card.
• DEQNA Ethernet
• RX02 drive
• Two RL02 drives for 20MB of storage

His name is catbert and he will be on the Internet one day. :)

Related posts:

• RL02 Sadness
• Making progress with the RX02 drive
• Making progress with RL02 Drives
• RL02 Spinup Failure
• RL02 debugging

Tags: oldcomputers bnl