IBM 610 Manual Of Operation

Also see for 610: Technical overview and introduction

58 IBM 6 10Octal SwitchThis is a three-position switch. "When the switchis ON, the machine operates in octal arithmetic.In the control-panel position, the control-panel wir-ing determines whether the machine is in octal arith-metic or not. When the switch is off, the machineoperates in the decimal mode.Master Stop SwitchThis switch is a spring-acting switch, which, whenflipped, restores the computer to the keyboard controlin case of faulty programming (e.g., dividing byzero) . All operations or instructions are released andthe A register is selected. Operation of the masterstop switch may cause a digit-check error and shouldbe used only in an emergency.CHECKING LIGHTS (Flashing Lights)When a checking light comes on, the rsm key mustbe used to get back into the program. The programmust be started at the beginning.Punch Check LightThe PUNCH CHECK light goes on when an oddnumber of punch knives have been driven throughthe paper tape giving a non-permissible character ina tape.Reg Sel LightThe REGISTER SELECTION light gocs on when aninvalid address is given for a register and an operationkey is depressed. If the operator does not completethe two-digit address of a register but punches onedigit and an operation key, the reg sel light will goon. If the machine does not select a valid register, thelight goes on.Digit Entry LightThe machine checks the digit code relays; and ifthere is not a permissible pattern, the light comes on,telling the operator the digit entered is invalid. Anytime the machine is in the enter state (following anENT command), the light comes on when an invalidnumber is entered.Redund LightThis light comes on when invalid information isgiven to the computer. If an invalid character is cre-ated within the computer, any attempt to use thecharacter will turn the light on.Clear LightIf the clear operation fails, this light comes on.Clearing is accomplished by subtracting the contentsof a register from itself, and zeros should result. TheCLR, CPY and ent operations apply to the selectedregister. The operations X, -^, ^X, and V requirethe clearing of the A register.Digit Check LightThis light comes on if the signals or digits to orfrom the drum are not a valid combination or code.The program must be started over if the light comeson.Overflow LightThis light comes on if a number exceeding allow-able magnitude is developed in the selected register.This light comes on when division by zero is at-tempted or if the numbers exceed the machine capac-ity when the -machine is in auto-point mode. Thenumbers in the original registers will usually bechanged in the case of overflow or exceeding capacity,but the contents of the A register are cleared.KB LightWhen this light is on, it indicates that the com-puter is under control of the keyboard.Punch Class Switch Light (Flashing)This light is flashing whenever one of the punchclass switches is on. Its primary purpose is to warnthe operator that a program is not being punched inclass 0.Operation LightThis light indicates that the machine was in theprocess of an operation when interrupted in automaticprogram. To turn this light off, hold down the intkey and repeatedly depress the rsm key until this lightgoes off. This light must be turned of before furtheruse of the keyboard, and no other keyboard keysshould be touched until it is off.