HP35: A Bit-Serial Wonder – 3. LED Magic

Part3. LED Magic

LED numeric display is the icon of HP classics. With just a single 5-bit register inserted, how could they design such a full-featured, flicker-free and properly PWM’d display that has 15 digits?

Sorry for such a long quiescence. Originally I was planning to actually make a board that drives the LED display before writing anything. Unfortunately, since quarter a year ago, I’m completely occupied by all sorts of things, and the plan is delayed forever. I’ll try if I’m free at some point in the future.

This is the first article written in the new “Gutenberg” WordPress editor. Noice!

[Status: Proofreading]

(The top image is a part of an advertisement of HP calculators. Cropped to fit in.)

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HP35: A Bit-Serial Wonder – 2. Bit What?

Part2. Bit What?

This article is about the “bit-serial” design scheme employed in HP35’s digital design.

[Status: Proofreading]

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HP35: A Bit-Serial Wonder – 1. Introduction

Part1. Introduction

In this section, we will have a brief look at the ISA of the HP35, the first look into the system.

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