Dilog DQ132 question

Dave McGuire mcguire at neurotica.com
Thu Apr 3 10:30:42 CDT 2008

On Apr 3, 2008, at 1:32 AM, tiggerlasv at aim.com wrote:
> I guess my first question would be -
> If you're running on an 11/83 under RSTS/E,
> why WOULDN'T you want to use 22-bit addressing?

   Well that was my thought...I've never used a 9-track drive on a 22- 
bit system running RSTS/E, so I was guessing a bit.  I thought  
perhaps the driver might implement bounce buffers if the board was  
operating in 18-bit mode.

   Later last night (in total screaming frustration trying to get at  
least ONE of my five 9-track drives working) I discovered that the  
driver identifies the board correctly and says "extended features  
disabled" in the HA LI output, then init disables the device.

> Surely you're not "wasting" a perfectly good 11/83 on V6C or  
> V7.0 ?   ;-)

   No way.  RSTS/E is, by far, my favorite PDP-11 OS...but only v9+.   
I'm definitely not a fan of the pre-v9 RSTS/E releases.  Most of my  
early computer knowledge was gained on a v9.4 system.

> You'll note that if you do a HAR LIST under RSTS/E V8.0 or above,
> it will flag this drive as "extended features enabled", indicating  
> that
> it can use the full 22-bit address range.

   Yup, I found that out later last night.  Of course the drive  
doesn't actually *work*, but that's a different (extremely  
irritating) matter.

> Set 18-bit addressing, in which case RSTS/E (V7.0)
> will see the controller as a TS11, which will ONLY be able to access
> 256K of memory without modification to the device driver.
> (V8.0 and above might (properly) recognize it as a TSV05 either way,
> however, the "extended features" will be disabled, and it will only be
> able to access 256K of memory.)

   I've got 4MB of RAM in the system; init disabled the device when  
it was set for 18-bit addressing.  (it's running v9.5)

   It seems that all of my 9-track drives are nonfunctional now.  At  
least two of them worked when put into storage; I'm very displeased.   
I've given up on them for the moment and am going to try to get a  
TK50 or TK70 working in the system.


Dave McGuire
Port Charlotte, FL

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