HP-35 Emulator - First scientific pocket calculator from 1972

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

x^y

log

e^x

CLR

√x

arc

sin

cos

tan

1/x

x⇄y

R↓

STO

RCL

CH S

E EX

CL X

HEWLETT•PACKARD 35

How to use

The HP-35 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-35, the world's first scientific pocket calculator from 1972, 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 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: