N8VEM
Encyclopedia
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
ECB Backplane (compact stand alone with 8 DIN 41612 slots)
ECB Bus Monitor (single step, address trap, bus status)
Disk IO (FDC & IDE drive expansion)
Zilog Peripherals (CTC, DART, dual PIOs)
Video Display Unit (80x25 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, 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)
uPD7220 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 (6809/6802/6502 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)
As of April 2011, boards are available for purchase. There is an active community development forum (N8VEM Google Discussion Group) from which additional board designs have been developed. There is active development of new boards underway.
Retrocomputing
Retrocomputing is the use of early computer hardware and software today. Retrocomputing is usually classed as a hobby and recreation rather than a practical application of technology; enthusiasts often collect rare and valuable hardware and software for sentimental reasons...
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
Single-board computer
A single-board computer is a complete computer built on a single circuit board, with microprocessor, memory, input/output and other features required of a functional computer. Unlike a typical personal computer, an SBC may not include slots into which accessory cards may be plugged...
carrying a Z80 microprocessor designed to run CP/M
CP/M
CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
and similar operating systems. It was created in 2008 by Andrew Lynch. Contrasted with the P112
P112
The P112 is a single-board computer carrying a Zilog Z180 microprocessor. It was designed by Dave Brooks in 1996, went out of production, and then brought back in 2004 by David Griffith. It's capable of running CP/M, but usually runs ZSDOS, an enhanced CP/M look-alike.- External links :* * *...
, which has some surface-mount components, the N8VEM SBC uses only through-hole components.
The N8VEM boards are designed with the free KiCad
Kicad
KiCad is an open source software suite for electronic design automation . It facilitates the design of schematics for electronic circuits and their conversion to PCBs design. KiCad was developed by Jean-Pierre Charras, and features an integrated environment for schematic capture and PCB layout...
Electronic design automation (EDA) toolset. Printed Circuit Board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
routing provided by FreeRouting.net Software is developed in Z80/8085 assembly language
Assembly language
An assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...
using the following toolset for MS-DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
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
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
design is supplemented using component libraries available here KiCad Libraries, specifically the Zilog
Zilog
Zilog, Inc., previously known as ZiLOG , is a manufacturer of 8-bit and 24-bit microcontrollers, and is most famous for its Intel 8080-compatible Z80 series.-History:...
Z80 CPU and Intel 8255
Intel 8255
The Intel 8255 Programmable Peripheral Interface chip is a peripheral chip originally developed for the Intel 8085 microprocessor, and as such is a member of a large array of such chips, known as the MCS-85 Family. This chip was later also used with the Intel 8086 and its descendants.It was later...
PPI chips.
Encourages low cost development and assembly by hobbyist amateurs using common tools such as 25 watt soldering iron
Soldering iron
A soldering iron is a hand tool most commonly used in soldering. It supplies heat to melt the solder so that it can flow into the joint between two workpieces.A soldering iron is composed of a heated metal tip and an insulated handle...
, multimeter
Multimeter
A multimeter or a multitester, also known as a VOM , is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter may include features such as the ability to measure voltage, current and resistance...
, logic probe
Logic probe
A logic probe is a hand-held pen-like test probe used for analyzing and troubleshooting the logical states of a digital circuit. While most are powered by the circuit under test, some devices use batteries...
(optional), and common hand tools. An oscilloscope
Oscilloscope
An oscilloscope is a type of electronic test instrument that allows observation of constantly varying signal voltages, usually as a two-dimensional graph of one or more electrical potential differences using the vertical or 'Y' axis, plotted as a function of time,...
is recommended but not required. Some basic electronic skills are helpful although the Printed Circuit Board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
is designed for relative beginners.
There are numerous N8VEM components available including an ECB
Europe Card Bus
- Europe Card Bus :The Europe Card Bus is a computer bus developed in 1977 by the company Kontron, mainly for the 8-bit Zilog Z80, Intel 8080 and Intel 8085 microprocessor families.-Physical format:...
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
S-100 bus
The S-100 bus or Altair bus, IEEE696-1983 , was an early computer bus designed in 1974 as a part of the Altair 8800, generally considered today to be the first personal computer...
boards in collaboration with S100Computers.com
- N8VEM 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 (?)
- N8VEM 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 drive expansion)
Zilog Peripherals (CTC, DART, dual PIOs)
Video Display Unit (80x25 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, 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)
uPD7220 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 (6809/6802/6502 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)
As of April 2011, boards are available for purchase. There is an active community development forum (N8VEM Google Discussion Group) from which additional board designs have been developed. There is active development of new boards underway.