I have the needed G888 moudules.
And i know about the external power supply. But i do. Not have the H716. In this reason i
powered the device from the second Outlet on the PDP-8e' s h724. The drive need 500mA
at 5v and also 500mA at -15v. Because i have only one backplane in the PDP-8 i think this
is no problem for the supply.
Marco
Am 18.05.2014 um 22:05 schrieb "Ian S. King" <isking at uw.edu>:
 
 Date: Sat, 17 May 2014 18:38:02 +0200
 From: Marco Rauhut <marco at familie-rauhut.eu>
 To: General Discussion: On-Topic and Off-Topic Posts
        <cctalk at classiccmp.org>
 Subject: Re: DEC TU56 dual drive and it's modules
 Message-ID: <5377906A.8060909 at familie-rauhut.eu>
 Content-Type: text/plain; charset=ISO-8859-15; format=flowed
 The tip with the look on the wiering of the backplane bring "light" into
 the darknes.
 Now the most Modules in right placees....
 Only two module places left for confirmation.
 Thanks to all so much!
 Am 16.05.2014 22:33, schrieb Tony Duell:
 > In the engeneering drawings "Module
Utilization" are shown special
> places for each module. In my drive the Modules on different places then
> in the drawing.
> Is the backplane a real bussystem or got i use the ports shown in 
 drawings?
>
> The T56 is most definitely not a bused backplane, the modules have to be
> in the right slots.
>
> I think exacltly which modules you need depeends on the controlleryou are
> uisng it with. So you might need ot check that.
>
> And DEC often drew the modual utilisation diagram looking a the _wiring_
> side of the backpl;ane, not at the modules. It's a mirror image of what
> you might expect.
>
> -tony 
 This may have been mentioned and I missed it, but just in case: if the
 drive unit was connected to a TCxx (typically a TC08) then it will not have
 the G888s in its backplane.  I believe you stated you want to connect this
 to a TD8E, in which case you need the G888s. I'm sorry to say, they are
 quite hard to find and when you do find them (quantity 5), you will pay
 dearly for them. That's been my experience - I have a TU56 that's been
 languishing while I try to locate G888s for less than a mortgage payment.
 Also, in case you haven't noticed this already: the TU56 has an internal
 power supply that runs the motors and some of the control circuits, but
 also requires an external supply for the logic.  -- Ian
 --
 Ian S. King, MSIS, MSCS
 Ph.D. Candidate
 The Information School
 University of Washington
 Madness takes its toll - please have exact change.