SOLVED! Sorcerer Cassette interface issue, or a MESSprogramming

Right. My design does both simply because it took just one more resistor and a switch contact to do it. I have found that useful, occasionally you find strobe patterns for one type of mains and not the other. Mine uses 4 DIL packages : 1) The master clock is a 4.9152MHz oscilalotr module. This is a standard one, used as the buad rate clock on some RS232 interfaces. 2.4576MHz is also useable, just change one conenction on the next stage. 2) A 74HCT393 dual 4-bit ripple counter. The 2 sctions are cascaded to give a /256 circuit, which is fed from the oscilaltor. This gives 19200Hz. Ifyou use the 2.45..MHz oscillator, just make this a /128 circuit. 3) A /12 or /10 counter/ I built this from a 74HCT163. Thr RCO ouput is inverted (I used a 2N3904 and 3 reistots for this to avod another IC package) and fed to the LD/ input. The parallel load inputs are jammed to 0100 or 0110 respectively (this is easy to arrange, D and A are grounded, C is tied high, B goes to a pull up resistor and the selector swithc to ground). Thus the counter counts up the appropriate number of times, then the RCO output is asserted, it reloads, and reperats. The D output of this counter is thus a clock at 16 times the required strobe frequncy. 4) Another 74HCT163, clocked from the D output of (3). The RCO outptu of that is this a 11:15 mark-space ratio signal at the required frequency (100 or 120 Hz). That drives another 2N3904 via suitable resistors, the collector load of that transistor is 4 white LEDs arranged as 2 parallel sets of 2 series-conencted LEDs with approrpaite limiting resistors. The onyl cotnrol is a 3 position rotary switch. -- the positions being off, 100 flashses/sec, 120 flashes/sec. One pole odf the swtich switches the +ve supply line to the rest of the circuit, anoterhpole controls the B input od that counter. -tony