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November 25th, 2009, 04:31 PM
N8VEM is a Z80 CP/M home brew computer project.
The N8VEM Single Board Computer is a home brew Z80 small computer project. It is made in the style of vintage computers of the mid to late 1970's and early 1980's using a mix of classic and modern technologies.
Designed with the free KiCad Electronic design automation (EDA) toolset. Printed Circuit Board routing provided by http://freerouting.net FreeRouting.net All software is developed in Z80/8085 assembly language using the following toolset for MSDOS called http://home.comcast.net/~tasm/ Telemark Cross Assembler (a.k.a. TASM) A major design goal is to use freely available tools to the maximum extent possible. You can help out too! The Printed Circuit Board design is supplemented using component libraries available here http://kicadlib.org KiCad Libraries, specifically the Zilog Z80 CPU and Intel 8255 PPI chips.
Encourages low cost development and assembly by hobbyist amateurs using common tools such as 25 watt soldering iron, multimeter, logic probe (optional), and common hand tools. An oscilloscope is recommended but not required. Some basic electronic skills are good but the Printed Circuit Board is designed for relative beginners.
Design principles include using low cost commonly available standard Transistor?transistor logic Dual In-line Package components such as 74LS using 0.1" spaced through hole technology. Design avoids usage of advanced printed circuit board construction techniques such as Surface-Mount Technology and custom and/or hard to obtain components. Also avoids usage of programmable devices such as Programmable Array Logic, Generic Array Logic, CPLD, and FPGA except for standard EPROM components.
Computer is designed to be a low cost Single Board Computer with simple IO. The current design supports a UART for serial IO and PPI for parallel IO. Includes Real-time clock for time keeping with battery back up and a small amount of NVRAM storage. While low cost is a key goal, the Single Board Computer is also designed to be a component in a larger bus based system. The Single Board Computer includes an http://de.wikipedia.org/wiki/ECB-Bus EuroCard Bus connector.
There are eight Eurocard ECB PCBs available: the SBC, the ECB backplane, the ECB bus monitor, the ECB prototyping board, the DiskIO board, the Zilog Peripherals board, the 6809 host processor, and the VDU.
In addition, there are S-100 homebrew PCBs such as the S-100 backplane, S-100 prototyping board, S-100 buffered prototyping board, and the S-100 IDE controller.
More ECB and S-100 homebrew PCBs are in development. New builders are always welcome to join.
The N8VEM Single Board Computer is supported by the SIMH simulator. The SIMH simulator allows for off target software development using a conventional personal computer.
Bit-Tech article (http://www.bit-tech.net/news/2009/01/12/the-n8vem-eight-bit-homebrew-pc/1)
Hack A Day article (http://hackaday.com/2009/01/10/n8vem-single-board-z80-computer/)
N8VEM Google Group (http://groups.google.com/group/n8vem)

Independent Third Party N8VEM Projects
Oscar Vermeulen\'s N8VEM Project Page (http://www.geocities.com/homeofoscarvermeulen/n8vem/n8vem.html)
James Moxham\'s N8VEM Page (http://www.instructables.com/id/Robot_Brain_Build_a_single_board_computer_in_an_e/)
Rolf Harrmann\'s N8VEM Project Page (http://hd64180-ecb.de/html/n8vem.html)
Rolf Harrmann\'s ECB Archive (http://hd64180-ecb.de/)
Twylo\'s N8VEM Photo Presentation (http://www.flickr.com/photos/twylo/tags/n8vem/)
N8VEM Project Log on Nekochan (http://www.nekochan.net/weblog/archives/2008/10/n8vem-completed.html)
Home Brew Computer Project thread on Vintage-Computer.com forums (http://www.vintage-computer.com/vcforum/archive/index.php/t-10499.html)
N8VEM on SIMH Simulator (http://www.schorn.ch/cpm/intro.php)

Similar Home Brew Computer Projects
P112 Project (http://en.wikipedia.org/wiki/P112)
ALPACA designers (http://tech.groups.yahoo.com/group/ALPACA_designers/)
Home of Z80 CPU Home Brew projects page (http://www.z80.info/homebrew.htm)