+
+
+Date: Thu, 30 Jul 1998 18:45:51 -0500
+From: Lee Saito <ksaito@concentric.net>
+To: Jimmy Hamm <jlhamm@pacificnet.net>
+Subject: Re: Rolling Thunder clock freqs
+
+Jimmy Hamm wrote:
+
+> >> I need to know the clock frequency and IRQ frequency of both processors,
+> so
+> >> if you could look at the E and Q lines (pins 34 and 35 of the 6809s) and
+> the
+> >> IRQ lines (pin 3 of the 6809s) that would be great!
+> >
+
+OK. I'm looking at the signals now...
+
+First, processor at 11A:
+
+pin 3 (IRQ line): Pulses vary in duration, making it somewhat difficult to
+determine frequency, but it's about 60 Hz (around 16 -17ms per pulse, 60Hz
+would be 16.6ms, I think) This seems to be tied to the sound processor?
+(pulses get real short when no sounds are playing)
+
+pin 35: approx 650 ns/cycle = 1.538 MHz
+
+pin 34: same as 35 (1.538 Mhz)
+
+Processor at 9A:
+
+Pin 3: Same as 11A (looks like 60Hz to me)
+
+Pin 35: Same as other processor (1.538 MHz)
+
+pin 34: Same as other processor (1.538 MHz)
+
+Hope this helps! ;)