Thanks for the explanation; I hadn't twigged the "missing tooth" really was physically missing, and thought you were trying to compensate for errors and whatnot
The way I'd approach it is as a once per revolution TDC signal pulse, then use a separate 08M to do the missing tooth detection which feeds the main PICAXE. The main PICAXE can then work either direct from a 'traditional TDC sensor' or from the 'tooth fairy'.
It also splits the project into two distinct parts, each of which can be fine-tuned individually. Modularisation has many benefits and PICAXE's are cheap enough to do that.
Using a PULSIN to detect the gap between teeth, a PICAXE should be able to toggle an output line when detected with fairly consistent and accurate timing ( fixed latency ) ...<code><pre><font size=2 face='Courier'> SetFreq M8
Main:
PulsIn pin,w0
If w0 < whatever Then Main
Toggle output
Goto Main </font></pre></code> If a PICAXE isn't up to speed, it should be a very short PICmicro program.
Toggling an output is perhaps better than pulsing it; the receiver has a full cycle in which to see the change so any processing time creep shouldn't miss a signal, and an interrupt can be used to catch rising edge the first time, falling edge the next. Then again you could generate a substantial length pulse knowing that you won't have missed a tooth during that time.
I was somewhat sceptical to start with, but now think it should be possible. Thanks for the enlightenmnet.