RE: 264/TED/Plus4 Story

From: Bil Herd <>
Date: Wed, 24 Aug 2011 20:05:35 -0400
Message-ID: <>
>That was the famous 555 timer chip if I read the circuit diagram right.
>Same way as the Reset was generated in the C64 on the older revisions.

>Thanks to whoever added the reset button to the 264. It always irked me
>that the C64 didn't have one.

Had to coordinate with the case designer but that was us.

>This design, even with the 6529 added caused me some confusion back
>then. I couldn't understand at first why the 2 joystick ports were wired
>n parallel and how the system was able to distinguish between them
>until I noticed that instead of GND they used a bufferd data line (D1
>and D2 if I remember right). This had the sideeffect that joysticks with
>built in auto-fire never worked right on a 264.

We tried to label the case Joy 0 and Joy 1 to match Terry Ryans beliefe that
the function calls should be joy(0), joy(1) and we almost made it through,
they caught it at the last moment.  The trick was to not put something like
that in too early or manager walk around with a case in their hand
complaining, narrow window right near the end.  Same time easter eggs get

>Sometimes I wonder what MOS did with all those I/O-chips... The only
>place I have ever seen a 6529 is a 264 system.

Same here. ;)

>schematic. I have seen other MOS-TTLs... Did MOS make those to tide over
>shortages? But why not label them 74xxx?

Yes and because they were in no way compatible with all of the specs. :)

>That was the time the PLA appeared in the 264? I do remember seeing a
>C116 prototype that didn't have it. How did you get them to give you
>permission to add even more chips to the design?

Simple: Jack had left.  We were now up to the 264 and we put extra sockets
in for software so we could use cheaper ROMS if we wanted or expand the
amount outright, and that lead to the bloated Plus4

The 364 was kinda cool though, hired the TI Speak and Spell guys to make it

>The 6567 before R7 were that bad? Since I live in PAL land I have never
>seen them and the 6569R3 and later always produced a very good picture
>f the Monitor was hooked up by Chroma/Luma.

I think so, I would get blood running from my nose and a migraine that would
last for 3 days from looking at an R5 since I recognized chroma noise for
what it was... and static clock noise and dynamic clock noise, and luma



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Received on 2011-08-25 01:00:16

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