Patent GB-1128518-A (GB)
Title: Improvements in and relating to computers
IPC: G01G19/415
Filed: 1966-05-10
Abstract: 1,128,518. Digital electric calculator. TOLEDO SCALE CORP. 10 May, 1966 [17 May, 1965], No. 20685/66. Heading G4A. A calculator for multiplying a sterling value by a number representing we ght includes a register storing the sterling, value, a register storing the number, and a register accumulating the product, partial products of the result being formed each as equal valued pulses equal in number to the value of the partial product and accumulated in the said register to form the sum. Price entry in shillings and pence is made in a circuit 63 which may comprise a series of switches allowing a voltage to be supplied to a diode matrix (Fig. 3, not shown) to produce a binary-coded decimal output. Weight entry, in tens, units, tenths and hundredths is produced by a light beam on a set of scales impinging on appropriate photo-cells (Fig. 1, not shown) the voltages resulting being applied to a decoder to produce appropriate binary coded decimal signals. The product is stored in register 72. A counter 61 causes the shillings value e.g. 4 to be supplied to a coincidence unit 74. This detects discrepancy with a previously reset counter 59 and enables an AND gate 76 to pass clock pulses. A second counter 62 causes the hundredths value of the weight e.g. 3 to be supplied to a coincidence unit 75 which detects a discrepancy with a reset counter 60 to enable a gate 77 which passes the clock pulses to a register 72. The clock pulses are also supplied to the counter 60. When the count reaches the weight value e.g. 3, coincidence unit 75 operates to inhibit AND gate 77 to stop further clock pulses from reaching the register 72, which thus stores, for instance, 3. Pulses are still applied to counter 60 which counts up to 9, then passes a carry to counter 59 which now reads 1. The coincidence unit is such that AND gate 77 is only enabled if counter 60 contains a number less than that of the weight factor being compared. When counter 60 is reset the pulses pass again into register 72. This continues until coincidence unit 74 operates to inhibit AND gate 76 when counter 59 contains a number equal to the shillings value. Coincidence unit 74 then causes the counter 62 to advance and allows the tenths value of the weight to be multiplied by the shillings, and similarly for the units. For the tens weight value gate 208 is inhibited and a gate 210 is enabled causing the clock pulses to pass through a decimal counter 211 before reaching counter 60 because in the embodiment described register 72 does not have a tens section and ten pulses must be supplied to the units section instead. When all the weight factors have been multiplied by shillings, counter 62 resets and advances counter 61 and causes the fractional shillings entry in register 72 to be multiplied by 12 and entered in the pence section. Then the pence value is multiplied by the weight values as described above. The shillings and pence are then multiplied by 1 and entered in a further register, not shown, to give the unit price. The results are then printed. Register 72 comprises a series of counters 235, 236, 264-268. Counter 235 receives the hundredths shilling value when AND gate 237 is enabled and is a decimal counter, the carry passing to counter 236. Counter 236 receives the tenths shilling value when AND gate 238 is enabled and is also a decimal counter. Counter 264 receives the units pulses (and the pulses resulting from the tens multiplication) and produces a carry when 20 is reached. Counter 265 stores the pounds sterling values. The contents of counters 235, 236 can be fed to the multiplier on lines 216-223 so that they can be converted to pence. Counter 226 stores the hundredths pence value during the conversion of shillings to pence and when the pence value is multiplied by weight. Counter 267 stores the tenths pence value and counter 268 stores the units pence value, a carry when 12 is reached being passed to the shillings counter. For printing the fractional pence values are rounded up.