hp 35 Platine
Computermuseum der Fakultät Informatik                          german

hp 35

hp 35
Type:          hp 35                              <<<    ***    >>>    ^^^
Manufacturer:  Hewlett Packard
Technology:    µP PMOS
Year:          1972
Price:         about DM 2000.-

The HP-35 was the first calculator by Hewlett Packard. First, 
there was no type designation at all. The oldest designs are only labeled 
with "Hewlett Packard". Later on it was called HP-35, supposedly because 
of the number of the keys.
It was not the first calculator which could evaluate trigonometric and 
arithmetic functions. The handling was adaptet, with its reverse 
"polish notation" to the desktop calculators hp 9100 and hp 9810.
However, it has only a one-line display, which shows the "Top of Stack".
Instead it has 4 stack-layers and a extra memory.
Technically, it is based on five ICs from the Mostek company. These 
build up a bit-serial microprocessor with a word-length of 13 Bits:
Three ROMs, one ALU with registerfile and a peripherial chip. 
On the beginning of the high-integrated circuits, bit-serial 
microprocessors were widespread.
The ICs get along with few pins and memory is simply realised with
shifting registers. Performance does not play an important role for 
a (desktop) calculator.

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