N8VEM

N8VEM is a homebrew computing project. It features a variety of free and open hardware and software. N8VEM builders make their own homebrew computer systems for themselves and share their experiences with other homebrew computer hobbyists. N8VEM homebrew computer components are made in the style of vintage computers of the mid to late 1970s and early 1980s using a mix of classic and modern technologies. They are designed with ease of amateur assembly in mind.
There are several N8VEM designs starting with a single-board computer carrying a Z80 microprocessor designed to run CP/M and similar operating systems. It was created in 2008 by Andrew Lynch. Contrasted with the P112, which has some surface-mount components, the N8VEM SBC uses only through-hole components.
The N8VEM boards are designed with the free KiCad Electronic design automation (EDA) toolset. Printed Circuit Board routing provided by FreeRouting.net Software is developed in Z80/8085 assembly language using the following toolset for MS-DOS called Telemark Cross Assembler (a.k.a. TASM) 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 here 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 helpful although the Printed Circuit Board is designed for relative beginners.
There are numerous N8VEM components available including an ECB backplane board is available to allow expansion boards to be used. Other components include video boards, disk controllers, peripheral expansion, and prototyping. The N8VEM homebrew computing project started producing several S-100 bus boards in collaboration with S100Computers.com.
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 it a modern-day version of the historic Homebrew Computer Club frequented by Steve Wozniak. Printed circuit boards of the mature designs are available from some of the members for the cost of the board manufacturing and shipping.
Bit-tech points out that this 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.
As reported by HACK A DAY, the single board computer is expanable using one of the backplane cards that can be built.
Completed N8VEM hardware and software has frequently been displayed at Vintage Computer Festivals.
There are no complete kits available -- builder's must procure thir own parts to complete 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.
Single Board Computers
# SBC V2 (Z80, UART, PPI, RAM with battery backup, ROM, RTC)
# SBC-188 (80C188 10-25MHz, UART, PPI, RAM with battery backup, ROM, RTC, FDC)
# Z8S180 Home Computer (Z8S180 33MHz, UART, ROM, RTC, Dual Interrupt controllers, Floppy, SD Card, 1MB RAM, AY-3-8910 sound, TMS9918A video)
# Z80 S-100
# m68k S-100 (In progress)
# 8086 S-100 (In progress)
# 6502/6809 ECB + carrier boards for other cpu's (?)
ECB Expansion Peripherals
* ECB Backplane (compact stand alone with 8 DIN 41612 slots)
* ECB Bus Monitor (single step, address trap, bus status)
* Disk IO (FDC & IDE (Parallel ATA) drive expansion)
* Zilog Peripherals (CTC, DART, dual PIOs)
* Video Display Unit (80×25 character mode video)
* Prototyping board with IO decode (buffered with labeled signal connectors)
* ECB Extended backplane (12 slot with 3U mounting features)
* DSKY (monitor/boot loader Hex LED display and keypad)
* Sprites, Color Graphics, & Sound (TMS9918, AY-3-8910, joystick/paddle interface)
* Prop IO (VGA, PS/2 keyboard, PS/2 mouse, micro SD (Secure Digital), prototyping area)
* Cassette Interface (KCS audio cassettes)
* 4MEM (4MB SRAM expansion for SBC-188)
* PPIDE (SBC parallel expansion port IDE interface)
* Juha SD (SBC SD card for mass storage)
* MSX Cartridge reader (load contents of MSX cartridges)
* MSX Cartridge (8K, 16K, & 32K EPROMs)
* µPD7220 V2 prototype (16 color video display)
* RAM-Floppy (4MB SRAM floppy drive replacement)
* 4PIO (64 GPIO input/output board)
* ECB to Z80 socket adapter (connect ECB boards directly to Z80 CPU)
* 6x0x host processor (Motorola 6800), MOS Technology 6502 CPU with ECB interface)
* 6x0x IO mezzanine (ACIA, dual PIA, PTC, power, and expansion bus interface)
* 6x0x ECB backplane (use ECB peripherals with stand alone 6x0x system)
There is an active community development forum () from which additional board designs have been developed. There is active development of new boards underway.

Main Menu

See Also

Main Menu