Casio Model AL-2000, S/N 205664
Functions: ASMD, square root, 4 memories
Programming: 30 steps, 14 instructions, no conditionals
Technology: DTL (SSI and discrete), MOS MSI, magnetic core memory
Display: 14 digits, miniature Nixie tube
Dimensions: 13-1/2"W x 16"D x 6"H, weight 15 pounds
Manufactured: Casio, Japan, 1970. (Sold by Remington)
This Casio AL-2000 from 1970 is a very early example of medium-scale integration (MSI) technology in a user-programmable electronic calculator. Although built primarily with a mixture of discrete-component diode-transistor logic and about 90 general-purpose SSI chips from Hitachi, the machine uses two special-purpose MSI chips manufactured by (American) Philco to provide a higher level of integration for some logic functions in the arithmetic unit. The date code on this MSI surface-mount flat-pack shows that it was produced in September 1968.
The AL2000 uses a magnetic core memory module to provide a total of 512 bits of storage, sufficient for four 14-digit memory registers and thirty 4-bit program instructions. The programs can be entered and edited from the keyboard, and are retained in the core memory when the calculator is switched off. Click on the link above for a more detailed description.