Re: [stella] Chip Select Line

Subject: Re: [stella] Chip Select Line
From: Chris Wilkson <ecwilkso@xxxxxxx>
Date: Sun, 12 Jan 2003 04:50:57 -0500 (EST)
Is the 7407 inverting or non inverting?  I think it's non-inverting, which
is what you'd need.  But it definitely has open collector outputs.  Did you
use pullup resistors on the outputs? It won't work without connecting a
pullup resistor from the output to VCC.

-Chris

On Thu, 9 Jan 2003, Kroko wrote:

> Hello !
>
> I have made a little testing with an original PacMan ROM chip.
> I made all the lines available for measuring the signals.
>
> If I connect all lines to the PacMan ROM, as in the original cartridge,
> everything works fine.
>
> What I did now is, that I connected the A12 line to an 7407 buffer and from the
> output of that buffer back to the CS line o the ROM. It is not inverting, so it
> should work. But it doesn't. Why not ?
>
> What are the timing requirements for the A12 line ? What am I missing ?
> It should work, shouldn't it ?
>
> Kroko.
>
>
>
>
>

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Current Thread
  • [stella] Chip Select Line
    • Kroko - Sat, 11 Jan 2003 19:23:22 -0500 (EST)
      • Chris Wilkson - Sun, 12 Jan 2003 05:01:37 -0500 (EST) <=
        • Kroko - Mon, 13 Jan 2003 10:43:20 -0500 (EST)
      • <Possible follow-ups>
      • mickey_m - Sat, 11 Jan 2003 20:36:12 -0500 (EST)