RL02 Spinup fails

william degnan billdegnan at gmail.com
Mon Nov 6 12:55:36 CST 2017

On Sun, Nov 5, 2017 at 12:43 PM, Aaron Jackson via cctech <
cctech at classiccmp.org> wrote:

> Hi everyone,
> I have managed to hook up an RL02 drive to my PDP-11 (thanks to Dave
> Wade for the drives) . This took me longer than I thought it would - I
> tried with a flat ribbon cable with a DIY terminator going straight into
> board , but couldn't get it to work. Removed the terminator, and the
> fault light turned off. So that's positive.
> I tried to load a cartridge, which I had cleaned, inspected and
> generally appears to be in good condition. It started to spin up and I
> could hear it getting faster, but after 30-40 seconds the fault light
> returns. I made a short video demonstrating this:
>          https://www.youtube.com/watch?v=japwBBodO8U
> According to the manual the fault light can appear for the following
> reasons:
> - Drive select error... Surely this would come on at the start?
> - Seek time out error... I'd have to hear the heads move first
> - Write current in heads during sector time error... Same as above
> - Loss of system clock... The fault light would be on from the start.
> - Write protect error... I don't think it got that far
> - Write data error... Same as above
> - Spin error... Is this the only remaining fault?
> So could the only cause be a spin error? I am wondering if the belt is
> slipping or something like that?
> Can anyone offer some advice?
> Thanks,
> Aaron.

At that point, for the time it takes the drive to be ready from a load
should be about 15 seconds.    For you the Fault light comes on instead.
If I turn on my drives but leave the computer (11/40) off, the fault light
comes on immediately.  If I then turn on the computer the fault light will
turn off, although I may have to press load first and if so it will turn
off after a few seconds.    It's independent of the LOAD/READY lights

based on this informal comparison I'd venture you have a drive issue.  I am
not 100% sure what your termination situation is.  I have two drives, one
terminated but it's with a DEC terminator on the bottom port of drive 1.
The cable comes from the computer into drive 0.  I have a cable going from
drive 0 port 1 to drive 1 port 1.


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