Motorola MC14500B
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The MC14500B Industrial Control Unit (ICU) is a CMOS one-bit microprocessor designed by Motorola for simple control applications in 1977.[1]
Overview
MC14500B (ICU) is well-suited to the implementation of ladder logic, and thus could be used to replace relay systems and programmable logic controllers, also intended for serial data manipulation.[2] The processor supports 16 commands, operating at a frequency of 1 MHz.[2] The MC14500B unit does not include a program counter (PC); instead, a clock signal drives a separate PC chip; therefore the size of supported memory is dependent on the implementation of that chip. It was still in production in 1995.[2]
The ICU architecture is similar to that of the DEC PDP-14 computer.Script error: No such module "Unsubst".Template:Clarification needed
The MC14500B was implemented with a transistor count of roughly 500 transistors. The chip was so simple not only because it only handled 1-bit computing data at a time, but also because the chip did not include a program counter, subroutine stack, etc. -- those required external chips.[3]
Developers
The ICU was conceived by Vern Gregory in the mid-1970s while working as an engineer in a marketing / applications group of Motorola Semiconductor Products Sector in Phoenix, Arizona, USA; Brian Dellande originated circuit and sub-routine designs, and co-wrote the manual; Ray DiSilvestro was the bench technician; Terry Malarkey provided management support.Script error: No such module "Unsubst".
In the CMOS Logic Division in Austin, Texas, USA (where it was made) Phil Smith was the chip designer; Mike Hadley provided product applications support.Script error: No such module "Unsubst".
Derivatives
A form of the design served as an embedded controller in a custom automotive chip made for Nippon Denso by Motorola—Japan.
I.P.R.S. Băneasa manufactured a clone of the MC14500B with the designation βP14500 in IIL technology (rather than the original CMOS).[4]
Notable uses
Script error: No such module "anchor".One of the computers known to be based on this processor is the educational WDR 1-bit computer (512 bits of RAM, LED, I/O, keyboard).[5]
A modern take, in retro style, of a computer based on this processor is the PLC14500-Nano. It is certified as Open Source Hardware PL000011 so anyone can learn from its design and can freely build it.
See also
References
Further reading
- Script error: No such module "citation/CS1". [1] (also: US 05/761,738; DE2801853A1)
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External links
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- ↑ Cite error: Invalid
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- ↑ Cite error: Invalid
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