[GreenKeys] BRPE wiring

[John Lawson]

Hi Doug!

The other thing to perhaps consider is the noise and cross-coupling that driving square waves at that much power, along conductors of any practical length - is bound to occur.  I'd second the motion of using low-level signals and amplifying them at the destination (BRPE) end. 

You can probably imagine just how I know this.    "Been there; done that; got the bloody t-shirt..."

IIRC there is a 'hammer-driver' class of IC still available, even though we generally don't print with hammers anymore.  Well, maybe you will....  ;}


Cheers
John KB6SCO
Carson City

-----Original Message-----
From: greenkeys-bounces at mailman.qth.net <greenkeys-bounces at mailman.qth.net> On Behalf Of Jones, Douglas W via GreenKeys
Sent: Sunday, September 20, 2026 1:30 PM
To: Greenkeys <greenkeys at mailman.qth.net>
Subject: [GreenKeys] BRPE wiring

In going over plans to make a new cable from the U of Iowa's PDP-8 Type-75 high-speed punch interface to our BRPE punch, I started worrying about the current flowing.