HP-45 Emulator - Scientific pocket calculator from 1973

Control & Timing
Current Address	0000
Return Address	0000
Pointer	0

	0	1	2	3	4	5	6	7	8	9	A	B	C	D
Status	○	○	○	○	○	○	○	○	○	○	○	○	○	○

Arith & Regs		Sign	Mantissa										Exponent
Register A		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register B		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register C		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register D		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register E		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register F		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register M		0	0	0	0	0	0	0	0	0	0	0	0	0	0

Data Storage		Sign	Mantissa										Exponent
Register 0		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register 1		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register 2		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register 3		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register 4		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register 5		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register 6		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register 7		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register 8		0	0	0	0	0	0	0	0	0	0	0	0	0	0
Register 9		0	0	0	0	0	0	0	0	0	0	0	0	0	0

y^x

log

10^x

SCI

√x

→R

SIN^-1

COS^-1

TAN^-1

x,s

→D,MS

D,MS→

Δ%

DEG

RAD

GRD

CLEAR

cm/in	kg/lb	ltr/gal





LAST X	𝜋	Σ-

(Press RCL first to activate timer)

HEWLETT•PACKARD 45

How to use

The HP-45 used Reverse Polish Notation (RPN).
You press the operation after inputting both numbers.

Start out by typing a few numbers. Example: 1 2 3
Press ENTER↑
Type in a few more numbers: 4 5 6
Press the operation, Example: +

What is this?

This is an emulation of the HP-45, the world's first scientific pocket calculator to include a shift key, from 1973, running on two different CPUS - the HP Control & Timing chip and the HP Arithmetic & Register chip. Alongside the two CPUs there are 3 ROM chips, a "Data Storage" (560 bits) chip, a keyboard, and a display, all being emulated with perfect synchronization.

Source code

It is my dream to build a chip library for anyone to be able to emulate any chip or board. Therefore, the code is subdivided into several layers of emulation:

Acknowledgments / Resources

This emulation would be lacking without the resources below: