There are several N8VEM designs starting with a
single-board computer carrying a
Zilog Z80 microprocessor designed to run
CP/M and similar operating systems. Contrasted with the
P112, which has some
surface-mount components, the N8VEM SBC uses only
through-hole components, consistent with the design philosophy that building should be within the skills and resources of non-professional hobbyists. The project also developed boards for other
CPUs, including the
Zilog Z180, the
Intel 80188, the
MOS Technology 6502, and the
Motorola 6809,
68000 and
68030. The N8VEM boards were designed with the free
KiCad electronic design automation (EDA) toolset.
Printed circuit board routing was provided by FreeRouting.net. Software is developed in Z80/
8085 assembly language using the
MS-DOS Telemark Cross Assembler program (TASM), as well as the open source
Small Device C Compiler. A major design goal is to use freely available tools to the maximum extent possible. The printed circuit board design is supplemented using component libraries available at KiCad Libraries, specifically the Zilog Z80 CPU and
Intel 8255 Programmable
Peripheral Interface (PPI) chips. The design philosophy encourages low cost development and assembly by hobbyist amateurs using common tools such as a 25-watt
soldering iron, a
multimeter, a
logic probe (optional), and common hand tools. An
oscilloscope is recommended but not required. Some basic electronics skills are helpful, although the printed circuit boards are designed for relative beginners. There are numerous N8VEM components available including
ECB and
S-100 backplane boards, allowing processor and expansion boards to be connected. Other components include video boards, disk controllers, peripheral expansion, and prototyping boards. In response to interest from members, the N8VEM homebrew computing project collaborated in developing a range of boards for the S-100 bus. These can be used to build new systems from scratch on that historic industry standard platform, or to restore and enhance vintage S-100 systems preserved from the 1970s and 1980s. Most of the S-100 board's initial design work was contributed by John Monahan of s100computers.com, with board layout, prototyping and testing contributed by Andrew Lynch and other N8VEM supporters. Some of these S-100 boards provide enhanced capabilities beyond what was available on original S-100 machines, some are replacements for historic S-100 boards, and others aim to apply the convenient bus architecture to processor families beyond the 8080/Z80 CPUs for which the bus standard was originally designed: notably, the 6502, the 68000, and later Intel CPUs. N8VEM is notable for being the largest and most active homebrew computing community in existence today. The project is entirely non-commercial and is made up of over 350 hobbyists, many of whom are actively involved in designing and prototyping the
hardware and
software. The community is a modern-day version of the historic
Homebrew Computer Club frequented by
Steve Wozniak and other pioneers of home computer development. Printed circuit boards of the mature designs are manufactured in small batches on a collective order basis, and distributed to members for the cost of the board manufacturing and shipping. The project does not provide complete kits—builders must procure their own parts to populate a board. Support is purely on a volunteer basis through a
Google Group and
wiki. Software is
open source and freely available for download from the wiki. The project was careful to keep things within the reach of the amateur computer hobbyist by using low cost and readily available components that can be assembled with simple hand tools. In addition, notable freeware system emulator
SIMH simulates the N8VEM SBC (along with many other architectures), providing a virtualized development environment that has the speed and flexibility of modern hardware. Completed N8VEM hardware and software has frequently been displayed at Vintage Computer Festivals. ==Single board computers==