Micropolis 1303

[Tony Duell]

> 
> Hi Tony,
> 
> I did try some other drives, namely some MFM drives
> I had to hand from a PDP 11. These were ST-412
> drives. 

Now wait a second... The PERQ needs uses DS0 and DS1 (Or DS1/DS2 if 
the drive numbers them 1-4) for the first and second drive. Now my PDP11s 
don;t have modern things like 5.25" wincheseters, but I was under the 
impression that on the normal PDP11 Qbus controller you set the drie to 
the hgighest drive select (DS3 or DS4 depeding on how they're numbered). 
You do want to check this.

> 
> I simply connected the existing PERQ controller to the
> new drive, hoping the hard disk would show ready, but
> no joy.
> 
> The drive didnt even show a flicker on the LED.

That really does sound like an drive select problem

> 
> The drives were all known working, and boot fine on a 
> 11/23. I didnt change any jumpers as the drives were 
> the only drive in the PDP 11's.
> 
> Could this mean a fault EIO card? 

It could. It might also be a fault in the DIB, incorrect drives select 
links, etc, etc, etc. I'd not suspect the EIO board _yet_

-tony