IBM 610 Manual Of Operation

Also see for 610: Technical overview and introduction

30 IBM 6 10to be depressed. The key depression is equivalent tosending an impulse to the control terminal. In thecase of a program tape, the machine reads the punchedholes in the tape and causes an impulse to be sent toa control terminal.There is a third class of hubs whose purpose isto affect the routing of electrical impulses fromsource to function hubs; logical operations dependupon the use of this class of hubs. Selectors, balancetest, program-skip and response hubs fall into thisclass.A set of source hubs (the program step hubs) isarranged on either side of the lower portion of thecontrol panel (Figure 21). There are 200 pairs ofthese hubs numbered in order from A-1 throughH-25. The two members of a pair are connected bya horizontal line. When an instruction is given totransfer control of the 610 to the control panel, thesepairs begin to emit electrical impulses, starting withthe step indicated by the light indicator panel onthe machine. The program step hubs emit, one pair ata time, in sequence at the rate of 18 impulses persecond. (The hub that emits after H-25 is the hubA-1.) Thus, when control-panel wires connect a suc-cesssion of program step hubs to a succession of func-tion hubs, the machine automatically performs thecorresponding functions or operations, one at a time,in order. This is similar to the succession of key de-pressions the operator makes when he is directing theactivity of the machine from the keyboard.Once the control panel is wired, it is equivalent toa punched program tape. When the 610 is under con-trol of the control panel, the program step hubs causethe machine to carry out the wired program by di-recting a sequence of timed electrical impulses to theset of control terminals within the machine. The orderin which the control terminals are to be impulsed isselected by the operator's wiring on the control panel.Transferring Control to the Control PanelIf a program involves several classes of instructionsor transfers to other control devices, the operator nor-mally does not attempt to compute as the programis being punched for the first time. However, in theexecution of one-time programs, there may be sub-routines wired on the control panel, which it is neces-sary to use in solving the problem. There are two com-mands that may be used in transferring control tothe control panel.(Control Panel)Depression of this key causes the machine to trans-fer control of the 610 to the control panel. The con-trol panel will begin executing instructions at the nextprogram step in sequence as indicated by the light in-dicator panel. This means that if the last program stepexecuted on the control panel was C-18, the lights willindicate C-19 and the machine will begin by execut-ing steps C-19, C-20, etc. The operator may observethe next step to be executed by referring to the calcu-lator light panel. (For a full discussion of the cal-culator light panel, see the section discussing thepanel.)Sequence Operation(Sequence)The depression of this key followed by the de-pression of two digit keys (giving a number in therange 00, 01, 02 —, 19) will cause the indicatedSEQ hub on the control panel to emit an impulse thatwill enable the 610 to utilize the machine functionsavailable on the control panel. A selector, balancetest, etc., may be activated with the available impulse.If the operator wishes to go to a program step onthe control panel that is not the next program step,he uses a sequence (seq) operation. The primary usesof these seq commands are in decision-making.Suppose, for example, that the operator wishes hisprogram to make a decision based upon whether thecontents of a register are positive or negative. He maygive a sequence command, say seq 10, which willcause the seq 10 hub on the control panel to emit animpulse. This impulse may be wired through the bal-ance test relays to make the decision, as will be ex-plained.