Reason for Voyager LCD colors

[Steve Simpkin]

(01-11-2024 05:55 PM)mdanoregon Wrote:  Hi,

Thank you.

The 1988 date on the 1LQ9 chip is really helpful since I have been wondering about this.

I saw a youtube video where the person speaking said they liked the older HP 15c's because they used sapphire when making the chips.

Are there dates on when HP stopped using this process or on what chips?

I'm curious if the voyagers prior to the 1LQ9 chips were made using sapphire.

It has been a common misconception that the original Voyagers calculators used a Silicon-on-Sapphire process which was responsible for its extremely low power consumption. In fact HP used a custom CMOSC process. This is explained in detail in the Jan 1983 issue of HP Journal magazine (page 23).
https://www.hpl.hp.com/hpjournal/pdfs/Is...983-01.pdf