Logos 328 Technology
Olivetti Logos 328 Covers off - front
The Logos 328 was a hybrid mechanical-electronic architecture like the Programma 101. It shared many parts and assemblies such as the keyboard and printer mechanisms. The complex mechanical keyboard seems very anachronistic and out-of-place in an electronic calculator but a long-established mechanical office machine company like Olivetti may have regarded this sort of mechanism as a simple and well-solved solution. Like the P101, the 328 was a serial machine with magnetostrictive delay line memory.Electronics
Olivetti Logos 328 Cordwood module packing
Olivetti Logos 328 Cordwood logic modules
The 328 is noteworthy like the P101 for its use of cordwood logic modules soldered in rows onto carrier boards, with the rows staggered on alternate boards so the the logic cage could be tightly packed. This result could have been achieved with one carrier board by placing the logic modules at twice the density. The carrier boards are double-sided and nicely made but the traces are quite thick and widely spaced. Perhaps this is part of the reason for the final arrangement because a more dense arrangement of modules would require more intricate PCB wiring and there may have been a limit to the trace size and density that Olivetti could achieve.
The logic boards have diagnostic edge connectors on their top edges, a nice touch that is nevertheless uncommon in these early machines.
The logic modules are identified with codes and no doubt will be found to be gates, inverters, flip-flops and similar.
Keyboard
Olivetti Logos 328 Keyboard Mechanism
The keyboard is clearly derived from mechanical calculator designs and despite the parts count and intricate assembly, was perhaps the fastest way for Olivetti to get a keyboard with BCD encoder, at reasonable cost.
Printer
The printer was inherited from the P101, both the 101 and the 328 being print-only machines. Print-only seems odd to modern users but would have been the familiar and typical experience for mechanical adding machine users who were meeting this machine for the first time. Advertising materials of the day often make a virtue of the full printed record as a confidence-builder for users to be able to verify that every operation of the ’electronic brain’ was in fact correct. Only later did users begin to assume technical correctness for any and every calculator operation.