Problems with a DEC RL-01 drive on a PDP-8/A

On 9/7/06, Mark Csele <mcsele at niagarac.on.ca> wrote: You didn't say anything in your message or on your web page about the READY light. Is it lit when you mount the pack? If it's lit, does it blink when you step through the bootstrap? It's a really fundamental thing, but since it seems that you recently acquired the system, did you lock the heads before transporting it? (small metal square with one screw on the corner that blocks the heads from sliding out during transport) If someone else locked them, did you _unlock_ them? If you moved the drive with the heads unlocked, that could be your problem. If there was a pack in the drive at the time, that _really_ could be your problem. Something else to check is the cable. I have a PDP-8/a w/RL8A. I recall that the controller-end of the cable is somewhat fragile (for those that don't have one to look at, it's not like an RL11; it's a bare Berg connector with 40-ish wires coming out of a round RL cable in a twisted fan - more like the cables I've seen for an RLV12). I know on at least one occasion, I had to repair one of the outer conductors of my RL8A cable because the wire popped out of the crimp-on pin in the Berg connector. As for your speculation on disk capacity, the RL01 is a 5MB unit, under OS/8, it presents three "devices" - an RL0A of 2MB, an RL0B of 2MB, and an RL0C with the remaining 1MB. Due to how it assigns the blocks, RL0A and RL0B are laid out somewhat efficiently; RL0C is the "leftovers", and when you use it, the disk seeks all over the place. It's not uncommon to use RL0C as an archival area and to not necessarily even load the drivers for it - freeing up a driver slot for, say, a floppy or other storage device. -ethan