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As they are usually low-cost, and have an especially low capital cost for development, single-board microcontrollers have long been popular in education. They are also a popular means for developers to gain hands-on experience with a new [[processor family]].
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== Origins ==
Single-board microcontrollers appeared in the late 1970s, when the appearance of early microprocessors, such as the [[MOS Technology 6502|6502]] and the [[Zilog Z80|Z80]],<ref name="ETI, Marvin" >{{Cite journal
|journal=[[Electronics Today International]]
|title='Marvin' - Z80 Control Computer
|author=Peter Grigson
|author2=David Harris
|date= August–October 1983
}}</ref> made it practical to build an entire controller on a single board, as well as affordable to dedicate a computer to a relatively minor task.
In March 1976, [[Intel]] announced a single-board computer product that integrated all of the support components required for their [[8080]] microprocessor, along with 1 [[kilobyte]] of RAM, 4 kilobytes of user-programmable ROM, and 48 lines of parallel digital I/O with line drivers. The board also offered expansion through a bus connector, but could be used without an expansion card cage when applications did not require additional hardware. Software development for this system was hosted on Intel's [[Intellec MDS]] microcomputer development system; this provided assembler and [[PL/M]] support, and permitted [[in-circuit emulation]] for debugging.<ref>[http://www.dvq.com/docs/brochures/intel_sbc_80_10.pdf Intel SBC 80/10 Single Board Computer brochure], 1976</ref>
Processors of this era required a number of support chips to be included outside of the processor. [[RAM]] and [[EPROM]] were separate, often requiring memory management or refresh circuitry for [[Dynamic random-access memory|dynamic memory]]. I/O processing might have been carried out by a single chip such as the [[Intel 8255|8255]], but frequently required several more chips.
A single-board microcontroller differs from a [[single-board computer]] in that it lacks the general-purpose user interface and mass storage interfaces that a more general-purpose computer would have. Compared to a [[microprocessor development board]], a microcontroller board would emphasize digital and analog control interconnections to some controlled system, whereas a development board might by have only a few or no discrete or analog input/output devices. The development board exists to showcase or train on some particular processor family and, therefore, internal implementation is more important than external function.
== Internal bus ==
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