Re: DRAM refresh

Date: Fri, 14 Oct 2016 13:52:32 +0200
Message-Id: <>
> On 2016-10-14, at 02:23, Jim Brain <> wrote:
> I've always wondered:
> 20 years ago, what transpired to get you from:
> "Hey, I wonder..."
> to
> "OK, here's how we'll figure out how the VIC works, without anything but the C64, an assembler, and the TV screen."
> I mean, I read the articles back in the day, but I never could connect the dots on how one figures out how to use software only to uncover the details.

Marko is one of those few persons whom I grew to respect well above average (even before we met for the first time) only by looking at his code from some x-ty years ago. I've been used to some demo-coders coding style on the 64 and when I realised that there are people who can program the way Marko did (does? :) - that was love at first sight (towards the programming style, obviously ;-)

That also reminds me about the dilemmas I / we had back in the days. When analysing some demo effects, utilising undocumented VIC "features" we were always thinking: "now that I see this, I understand, that when I put this bit here and that bit there at the cycle x counted from raster IRQ triggered at line y (why on Earth that line and not any other???) then I get the effect on screen. OK - I see this I can copy and modify the code but HOW ON MOTHER EARTH SOMEONE COULD HAVE GUESSED THAT THIS NEEDS TO BE DONE IN SUCH ORDER TO GET SUCH EFFECT?!!!"

It was unbelievable that someone could "guess" such complex sets of conditions to get some undocumented effects. On the other hand it was inconceivable to analyse the hardware innards of the VIC without its blueprints (or die shots today...)! Only once I got to know Marko, I realised that it didn't have to be guessing and "luck". That it could still be hard science that lead to discovering the extra VIC features but still it was totally amazing how such analysis could have been done basically with "the C64, an assembler, and the TV screen."


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Received on 2016-10-14 12:01:36

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