180 Part 2 The instruction-set processor: main-line computers
Section 2 Processors with a general register state
in the cabinets to each logical circuit in such a way as to reduce the amount of wire needed. When the layout has been completed, the last stage of producing the wire lists can proceed.
General construction of machine
The main units are shown in Fig. 10.
The package frame. This unit is a simple light-alloy frame supporting diecast light-alloy frame racks to which the back socket panels are fixed. The packages slide into grooves in the rack and plug into sockets at the back, a polarizing feature preventing the insertion of a package upside down. If electrical or magnetic screening is necessary between any packages, a special metal plate is inserted in slots in the cast rack and is fixed by a single screw in the back panel. Coded aluminium strips containing coloured plastic studs which identify the position of each package are fixed to the front of each casting.
Arrangement of the packages. There are 200 packages per cabinet, arranged in ten horizontal rows of 20 units per row. The metal valve panels are placed so that the edges almost touch. The component panel of each unit is in register with the unit in the corresponding position in each of the other rows, thereby providing vertical chimneys for cooling the components secured to these