RL01 drive select plug and power supply questions

Allison ajp166 at bellatlantic.net
Fri Oct 21 06:43:04 CDT 2005

>Subject: Re: RL01 drive select plug and power supply questions
>   From: Johnny Billquist <bqt at Update.UU.SE>
>   Date: Fri, 21 Oct 2005 13:16:33 +0200 (CEST)
>     To: cctalk at classiccmp.org
>On Thu, 20 Oct 2005, Allison <ajp166 at bellatlantic.net> wrote:
>> >Subject: Re: RL01 drive select plug and power supply questions
>> >   From: David Betz <dbetz at xlisper.mv.com>
>> >   Date: Thu, 20 Oct 2005 18:26:02 -0400
>> >     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>> >
>> >Thanks for your reply. I guess I'm okay with power even if I leave in
>> >the DHV11 as it seems my BA11-N has been upgraded to a H7861 power
>> Unless you need the IO I'd pull it anyway. The system will run cooler
>> and I doubt you have need for the lines.  DHV11 is a MUX and you need
>> the chassis kit to break out all the serial lines.  Most OSs for PDP11
>> don't use it (system build time option) and the DLV11J is easier to use
>> and program.  The DHV11 cannot be used for a console either.
>I think I'll slightly disagree with you here.
>While all you say is essentially true, the DLV11 is a tremendour burden on
>the system compared to the DHV11. So if you actually want to run serial
>connections to a machine, keep the DHV11, and don't use the console more
>than absolutely neccesary.
>Big difference between DMA and interrupts you know...

Yes I do.  However for a single user system the load is not an issue.
If your running a timeshare system such as RSTS or RSX with more than one
user then DHV11 sense as well.

For most of my 11s four lines is the limit for what I can seem to keep busy.
Figure a user terminal, LA100 Printer and serial line for modem or data 
line to another system. At the extreme I've run two terminals for OSs 
that support that but, I can only type on on at any instant. ;)


More information about the cctech mailing list