Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!paravia
From: paravia@csd4.milw.wisc.edu (Mark David Kakatsch)
Newsgroups: sci.electronics
Subject: Re: S-100 update
Message-ID: <994@csd4.milw.wisc.edu>
Date: 14 Feb 89 23:05:00 GMT
References: <885@csd4.milw.wisc.edu> <1407@ncar.ucar.edu>
Sender: news@csd4.milw.wisc.edu
Reply-To: paravia@csd4.milw.wisc.edu (Mark David Kakatsch)
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Organization: University of Wisconsin-Milwaukee
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In article <1407@ncar.ucar.edu> cook@stout.UCAR.EDU (Forrest Cook) writes:

>
>I have an old Imsai and the reason your bus has non-square waves is probably
>due to the fact that the front panel's LEDs are connected directly to the
>bus with NO buffering.  Who did that anyway?  If you want to make the thing
>work much more reliably,  kludge in some octal buffer chips between the
>bus and the LEDs.  While you are at it, it might not hurt to cut the power
>switch traces that run about 1/4" from a bunch of one-shots and run the AC
>right to the switch.  220/330 ohm terminator resistors on all of the bus
>lines will also clean up the signals.
>Remember the front panel will only work with CPU cards that have the CPU
>data bus availible on a 16 pin socket, and port FF is used by the front
>panel data in/out port so beware of address conflicts.

etc...

Those are some good suggestions, however, I get a triangle wave even when the 
front panel is not connected, and I run a little program that loops to itself
in ROM...It doesn't, however, seem to affect the operation of the board, as 
it DOES work...Just wish I could get those damn drives going...

Mark


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