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   Original URL : https://retrobrewcomputers.org/doku.php?id=boards:sbc:mini_mc14500:mini_mc14500
   Snapshot date: 2025-11-17
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==== Table of Contents ====

[[#mini_mc14500|Mini MC14500]]

[[#introduction|Introduction]]

[[#hardware_documentation|Hardware Documentation]]

[[#build_information|Build Information]]

[[#builder_s_notes_comments|Builder's Notes/Comments]]

[[#photo_gallery|Photo Gallery]]

[[#file_list|File List]]

====== Mini MC14500 ======

{{https://retrobrewcomputers.org/lib/exe/fetch.php?w=400&h=254&tok=9c624e&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fboards%2Fsbc%2Fmini_mc14500%2Fmini_mc14500.jpg?400x254|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_boards_sbc_mini_mc14500_mini_mc14500.jpg}}

===== Introduction =====

The Mini MC14500 SBC is a very simple board built around the Motorola MC14500B ICU (Industrial Control Unit) https://en.wikipedia.org/wiki/Motorola_MC14500B. The impetus for this board was an article on the VASTOR processor that was built at the University of Toronto. The following article explains that processor http://www.dissonance.com/archive/journals/Loucks82.pdf. This board is not a VASTOR processor but a single ICU proof of concept based on reference design from Motorola.

All Data, Instruction and Clock entry is done via switches.

The Mini MC14500 board has the following features

8 LED's for state output

6 Switches for programming and data input

Expansion header to allow direct connection to say a parallel port for control by another CPU.

The silk screen for the board has all of the OP codes for quick reference

===== Hardware Documentation =====

Board: [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:mini_mc14500_board_layout.pdf|mini mc14500 Board Layout]]

Schematic: [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:mini_mc14500_schematic.pdf|mini mc14500 Schematic]]

KiCAD and Manufacturing Files: [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:minimc14500_-_kicad.zip|mimi mc14500 KiCAD and Manuf]]

===== Build Information =====

BOM: [[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:minimc14500_bom.xls|Mini MC14500 BOM]]

**Test Programs**

To run the test programs you need to undertake the following as the precursor

Data: 1

Control: IEN (1010)

Clock

Control: OEN (1011)

//**Logical AND example**//

Data: 1

Control: IEN (1010)

Clock

Control: OEN (1011)

Clock

LD (0001)

Clock

AND (0011)

Clock

STO (1000)

Clock

===== Builder's Notes/Comments =====

Note the currently manufactured board has a single erata that requires the cutting of one track and soldering of one wire between 2 points. The build files have not been updated.

The build is very simple. Install

Resistors and capacitors

Transistors and IC sockets

LED's

Switches

Undertake the required modification as per the erata photo

===== Photo Gallery =====

[[https://youtu.be/GkPj3lOSu30|Demonstration Video]]

Bare board

{{https://retrobrewcomputers.org/lib/exe/fetch.php?w=400&h=300&tok=0c8dfd&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fboards%2Fsbc%2Fmini_mc14500%2Fimg_8359.jpg?400x300|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_boards_sbc_mini_mc14500_img_8359.jpg}}

Erata Photo - Rear cut and wire jump

{{https://retrobrewcomputers.org/lib/exe/fetch.php?w=400&h=300&tok=cc7f31&media=https%3A%2F%2Fwww.retrobrewcomputers.org%2Flib%2Fplugins%2Fckgedit%2Ffckeditor%2Fuserfiles%2Fimage%2Fboards%2Fsbc%2Fmini_mc14500%2Fimg_8367.jpg?400x300|www.retrobrewcomputers.org_lib_plugins_ckgedit_fckeditor_userfiles_image_boards_sbc_mini_mc14500_img_8367.jpg}}

===== File List =====

Filename

Filesize
Last modified
[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:img_8359.jpg|img_8359.jpg]]
1.8 MiB
2019/01/16 20:14
[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:img_8362.jpg|img_8362.jpg]]
1.9 MiB
2019/01/16 20:14
[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:img_8367.jpg|img_8367.jpg]]
1.9 MiB
2019/01/16 20:15
[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:mini_mc14500.jpg|mini_mc14500.jpg]]
783.4 KiB
2019/01/16 20:23
[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:mini_mc14500_board_layout.pdf|mini_mc14500_board_layout.pdf]]
123.9 KiB
2019/01/16 19:54
[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:mini_mc14500_schematic.pdf|mini_mc14500_schematic.pdf]]
74.9 KiB
2019/01/16 19:41
[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:minimc14500_-_kicad.zip|minimc14500_-_kicad.zip]]
181.2 KiB
2019/01/16 19:46
[[https://retrobrewcomputers.org/lib/exe/fetch.php?media=boards:sbc:mini_mc14500:minimc14500_bom.xls|minimc14500_bom.xls]]
8.0 KiB
2019/01/16 20:36