Editing IBM 305 RAMAC (section)

===Jumps===
The 305's instruction set does not include any jumps, instead these are programmed on the control panel:

* Unconditional jump &ndash; the program exit code (P field) specifies a ''Program exit hub'' on the control panel, which has a wire plugged into it and, via distributors, to ''Program entry hubs'' specifying the first, second and third address digit of the instruction to jump to.
* Conditional jump &ndash; the program exit code (P field) specifies a ''Program exit hub'' on the control panel, which has a wire plugged into it and the appropriate ''Condition selector common hub'' to be tested, the corresponding  two ''Condition selector output hub''s have wires plugged into them and the ''Program entry hub''s specifying the instructions to jump to or the ''Program advance hub'' to continue in sequence. Complicated conditions involving many ''Condition selectors'' could be wired to execute in a single instruction (e.g., Testing the sign and zero states of multiple accumulators), with one of several ''Program entry hub''s activated.
* Multi-way jump &ndash; the destination track (T<sub>2</sub> field) is set to <code>-</code> and the appropriate ''Character selector hub''s on the control panel have wires plugged into them and the ''Program entry hub''s specifying the instructions to jump to or the ''Program advance hub'' to continue in sequence.