Re: [stella] pin description for 6507?

Subject: Re: [stella] pin description for 6507?
From: Emmanuel Fernandes <fernandes@xxxxxxxxxxxxxx>
Date: Wed, 31 May 2000 22:20:14 +0200
Hi Richard,

	The pin 1 of the 6507 is the /RESET pin. This is an active low input: a
reset on the CPU is produced when this pin is going low. In my Atari
2600jr, pin 1 is connected to pin 4 of a 4050 non-inverting hex buffer,
which is always HIGH since the input of that gate is always HIGH. In in
an older Atari,  pin 1 is directly connected the the +5V with a 24k
resistor in betwen. So, I think if you tie it to HIGH level, everything
should work right.

Pin 2 is Vss, so it should be connected to GND :-)) !



"Kennehan, Richard" wrote:
> I cut out the part of the 2600jr circuit board that contains the RF
> modulator and replaced it with perfboard, so that I would have lots of room
> for not only the composite video mod, but future mods as well.
> So currently, my circuit board looks like this, with the section marked with
> a "P" as perfboard
>    +---------+
>    |         |
>    |         |
>    |     +---+
>    |     | P |
>    +-----+---+
> Unfortunately, pin 1 and 2 of the 6507 extended into that region that I
> chopped off, and now the Atari won't work.
> I consulted the atari schematic diagrams that someone posted on the
> internet.  It shows pin 1 to be the RESET pin. Should this be tied high or
> low voltage?
> Does anyone know what pin 2 of the 6507 does?  It is not mentioned on the
> schematic.
> A complete pin description of the 6507, RIOT, and TIA would be a great
> addition to the 2600 programming faqs.
> --
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