Analysis of information sources in references of the Wikipedia article "IBM 1401" in English language version.
The timing of the IBM 1401 is described in terms of the time required for one complete core storage cycle, which is 11.5 microseconds ... The time required for any internal processing instruction is always a multiple of this interval of time.
The 1401's clock frequency is 86,957 cycles per second, or about 87 kiloHertz! This corresponds to an 11.5 micro-second system clock cycle time. ... The 1401 CPU does everything in a character-serial manner. In order to add say two N-digit numbers, the CPU takes several cycles to fetch the instruction itself and then one cycle for every character of the instruction's two operands or arguments, or 2N cycles total.
The timing of the IBM 1401 is described in terms of the time required for one complete core storage cycle, which is 11.5 microseconds ... The time required for any internal processing instruction is always a multiple of this interval of time.
