Review: Swiss Micros DM41X

[Steve Simpkin]

(12-29-2020 11:09 AM)Chr Yoko Wrote:  I believe the 28C was the first HP with a dot matrix LCD.... and it was pretty hard to read if you are not at the exact requested viewing angle.

Yes the HP-28C (1987) was the first HP "scientific" calculator to use a dot matrix LCD. The financial model HP-18C introduced a year earlier (1986) used the same hardware and LCD. HP also had previously used a dot matrix LCD in the HP-75C (1982) and HP-71B (1984) handheld computers. The HP-71B was the first handheld to use the Saturn processor used in later calculator models.

The HP-28C was such a groundbreaking model that brought symbolic math and early CAS to handheld calculators. It's interesting that HP created the processor (Saturn), created their own computer language (system RPL) and wrote all of their own code used in the HP-28C. When TI decided to make their first symbolic calculator (the TI-92) eight years later, they used an off the shelf processor (Motorola 68000) and acquired a company (the Soft Warehouse) with an existing CAS (Derive) to help implement it. The specs on the TI-92 are very similar to the first Apple Macintosh (and Lisa).