Commodore P50

Brief History

Commodore has a full spectrum of calculators from four-function basic models to most sophisticated scientific, or programmable types. To reach even lower prices, the 1978's new models were planned to assemble in Hong-Kong, using MPS 7561 chip family from MOS Technologies to made a wide variety of calculators built on identical printed circuits. The completed five models (financial F4902, the algebraic logic scientific SR4912 and SR9190, RPN scientific SR4921, and the programmable scientific P50) use the well-known housing, but have cheaper buttons rather than injection molded keys. The invade of mass-produced japanese calculators with LCD displays don't let these models to become hits, and confirms the management of Commodore that researching computers rather than calculators is the only way to survive. A year later, after running out the last series Commodore had stopped manufacturing calculators.

The P50 from the series Decision Maker would be comparable to non-programmable scientific models rather than the earlier P100 model. It can store only 24 steps, and has only one memory register, so more complex mathematical problems couldn't be solved with this machine, although it has three kinds of conditional jump instructions which allows branching of programs depending on the displayed number.

Technical specifications

Manufacturer:	Commodore Business Machines (USA/Hong-Kong)
Mfg. date:	1978
Size:	8,1×15,2×4 cm
Weight (ready for operate):	n.a.
Type:	programmable scientific
Capacity:	8/8+2 digits (input/display) 10+2 digits (internal precision)
Operating logic:	algebraic
CPU:	MOS MPS7561 008
Registers:	2 standard (with saving the pending operation) 1 memory (with aritmetic)
Features:	+/-change sign (direct entry of negative numbers) RVexchange registers (X-Y) Ffloating-point notation Sciscientific (exponential) notation Sqrsquare root x²square pivalue of pi (3.1415..) can be recalled 1/xreciprocal trigtrigonometrical functions (sin, cos, tan and inverses: arcsin, arccos, arctan) logexponential and logarithmical functions (10- and e-base) y^xraising to power n!factorial
Display:	14 digit LED
Power:	9V battery or adaptor
Programming method:	non-programmable
Test results:	trigonometry:result of sin^-1(cos^-1(tan^-1(tan(cos(sin(60°)))))), reference value: 60. 60.01228245 exponential:result of 0.999¹⁶⁰⁰⁰⁰, reference value (first 14 digits): 3.0068804206375×10^-70 3.006896579E-70

Pictures

P50

Inside of the P50

Detailed Description

Using

Most functions can be used same way as with other scientific calculators, only the programming model has to be described. To switch to programming mode, and return to computing-running mode, press the lrn key. In this mode, the current step number will be displayed in the lefmost digits on the display. The P50 doesn't show the stored keycodes at the current step, but program editing is possible with the single-step (SSTP) key. Pressing any other key overwrites the current program step. The R/S key can be used to stop the program, the GOTO followed by a two-digit step number causes program jumping to the specified step. These keys are used in the computing-running mode too: R/S starts the program from the current step, SSTP executes only one step, GOTO followed by a two-digit number is used to set the current program step. The three branching instruction skip the next instruction if the displayed number is zero (SKZ), negative (SKN), or positive (SKP).