What kind of computer could you build in 1967? Well, if you were reading Wireless World (a UK magazine) and had a good bit of spare cash, you could build [Brian Crank’s] Wireless World Computer. You only needed 400 germanium transistors, 1800 resistors, and an odd number of capacitors, switches, diodes, and neon bulbs. You also needed a good bit of patience, we suspect. In 1967, the computer cost about 50 pounds to build (perhaps $125 at 1967 exchange rates which would now be about $900 in today’s money). To save parts (and thus money and build complexity), the computer used a trick: it processed data one bit at a time. Many older computers did this, including another UK computer named EDSAC. read more http://hackaday.com/2015/10/29/400-transistors-and-1800-resistors-form-this-1967-personal-computer/
good old ddl logic .. moved during the late 60's to dtl and then at the dawn of the 70's to ttl .. though the first ttl chips were available well before that article was written.. in 1964 .. and it is ddl.. the designer is using the transistor c/e diodes as switched diodes rather than direct logic circuits.. oddly he could have used the same number of components and run it in a direct ttl arrangement.. maybe germanium transistor specs were too wide.. (I note he's running the germaniums in the saturated part of their curves) so in that case why didn't he use say the BC108 silicon transistor which was by then cheap and readily available?
