My Big Trak has an 82K resistor (Gray Red Orange) and a 100pF cap (Brown Black Brown). H2H Football has an 39K resistor (Orange White Orange) and a 100 pF cap (101J). I measured the Big Trak resistor in circuit at 83.8K and the H2H Football resistor out of circuit at 39.3K. My meter won't go as low as 100pF to check the caps.

Before I pulled the chips, I measured 195Hz between pins 1 and 4 of H2H Football, and 588 Hz between pins 26 and 4 of Big Trak.

Those are both E revision dies; you think that has anything to do with it? Remember when I hooked up some TMS1100s to the Entex Baseball 3 cap and resistor to measure its frequency? Es were faster than Bs. Measuring the frequency slowed it way down, but it's possible that the ratio of B speed to E speed is correct. That would make Es 11-12% faster.

Originally Posted By seanriddle
Originally Posted By hap
Ok, Entex Baseball 3 is working in MESS. I'll update the notes if you worked out how to measure its osc freq.

I connected the cap and resistors from BB3 to 4 other TMS1100s - two were B-revision dies and two were E-revision. Interestingly, the Es are faster than the Bs- B amateur = 169K, B pro = 218K, E amateur = 188K, E pro = 244K. The original chip was a B, so I guess 169K/218K is the way to go.

Last edited by seanriddle; 04/26/15 03:11 AM.