- alt.comp.hardware.homebuilt FAQ Version 20 (modified 06/18/97)

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alt.comp.hardware.homebuilt FAQ Version 20 (modified 06/18/97)

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Archive-name: homebuilt-comp-FAQ
Posting-Frequency: Every two weeks


This file contains frequently asked questions (FAQ) and general information
pertaining to the newsgroup alt.comp.hardware.homebuilt. It is maintained
by Mark Sokos ( It is posted every two weeks to the
newsgroup alt.comp.hardware.homebuilt. The latest version may also be
obtained by sending an e-mail request to the above address.

This file is available via FTP from


A DOS text version is available from:

   * Dave Baldwin's FTP site
   * The Computer Journal (TCJ FTP)

An HTML version is available online at:


This file is (C) copyright 1996, 1997 by Mark Sokos. It may be freely
copied and distributed as long as this notice remains intact and the file
is not modified, and no fee is charged for its duplication.


1.0 What the group is about

     1.1 What the group is about
     1.2 How to deal with the Cancelbot
     1.3 Who is PRR?

2.0 Questions
     2.1 Can I post ads on the newsgroup?
     2.2 Can I post questions involving hardware problems?
     2.3 What's this about a new homebuilt newsgroup?
     2.4 What is a "Wally"? (and other terms specific to this newsgroup)
     2.5 Where can I get an EEPROM/PLD programmer?
     2.6 How can I make my own SIMMS?
     2.7 How do I interface to an IBM Clone?
     2.8 How do I interface to a Mac?
     2.9 Where can I find bus timing and information?
     2.10 Where can I get hard drive specs and interfacing info?
     2.11 Where can I find MIDI and other musical interfacing information?
     2.12 How can I make my own circuit boards?
     2.13 What is the Net Station?
     2.14 How do I homebrew an LCD controller?
     2.15 How do I make good front panels/cover plates?
     2.16 What are PDF and Acrobat files?
     2.17 Where can I get technical information about Game Boy?
     2.18 How can I build a POST code reader for my PC?
     2.19 Where can I find information on IR standards?
     2.20 How can I make a mouse serial/ps2 or ps2/serial adapter?
     2.21 How can I convert video formats?
     2.22 Where can I find caller ID information?
     2.23 Where can I find information about projects?
     2.24 Where can I find standards for multi-processors?
     2.25 How do I make loop-back plugs?
     2.26 How do I make a null modem/laplink cable?
     2.27 Where can I get schematic drawing, circuit simulators, schematic
     capture programs, and PCB layout software?
     2.28 Where can I get software developement tools?
     2.29 Where can I find operating system information?
     2.30 How do I interface to DRAM/SIMMS?
     2.31 How do I turn myself into a cyborg?
     2.32 Who makes kits?

3.0 Where to get more information
     3.1 Semiconductor Manufacturers
     3.2 Vendors
     3.3 Internet Resources
     3.4 BBS Numbers
     3.5 Book/Magazine List
     3.6 CD Rom

4.0 Misc.


1.0 What the group is about

1.1 What the group is about

This group was formed for the discussion of homebuilt computer hardware, as
the name implies. The term "homebuilt" or alternately, "homebrew", refers
to the hobby of building electronics at home, generally with a soldering
iron or wire wrap. No knowledge or experience is required for posting to
this group. Postings may deal with real hardware, or absract concepts, and
are not restricted to any specific cpu or architecture. Topics may also
include homebuilt peripherals added to existing off the shelf systems, or
hardware hacks to existing systems/accessories.

Please note: Unfortunately, the term "homebuilt" causes a great deal of
confusion amongst IBM clone builders, which leads to a large number of
inappropriate posts on this newsgroup. This group, as a general rule, is
not for discussion of IBM related hardware, unless there is some aspect of
home built electronics involved, such as connecting your own device to an
IBM serial/parallel/game port, etc. or using IBM clone hardware as part of
a homebuilt design (non-IBM design). Common IBM clone hardware hacks, such
as overclocking and changing the UART chip, are best discussed in one of
the IBM related newsgroups. An IBM clone hardware questions pointer is
posted frequently on news.answers, and due to its length the information
within it will not be repeated here.

Warning: Any post that may be considered an "" post is likely
to draw flames or intentionally misleading advice from the regulars at
a.c.h.h. Following such advice for a "fix my PC" type post may be damaging
to your computer. You have been warned.

1.2 How to Deal With the Cancelbot

Because of excessive noise (mostly involving off topic "fix my PC" type
questions) a cancelbot has been set up on this newsgroup. Failing to inform
the cancelbot that you have read the posting rules may result in your post
being automatically cancelled. To let the cancelbot know that you are aware
of the posting rules, you must add the letters "PRR" (without the quotes)
somewhere in your first post. PRR stands for "Posting Rules Read". These
letters do not need to be included on subsequent posts.

Questions or comments about the cancelbot should be directed to

1.3 Who is "PRR"?

See the previous section. Some people mistakenly add PRR to every post
(only your first new thread needs these letters). Some people have mistaken
it for a signature. Because the letters may be included anywhere in the
post, some people have taken to creative uses of the letters, which include
the fabrication of information about a mythical person with the initials
PRR. At the time of this writing, PRR has been in the hospital, and is
known to have an affection for Milk Duds. New readers are free to
contribute to this on-going "story".

2.0 Questions

Answers to specific questions are included in this section. Many of the
answers are only pointers to more information, so that large volumes of
information are not duplicated unnecessarily.

2.1 Can I post ads on the newsgroup?

As a general rule, alt.comp.hardware.homebuilt is not a forsale group and
thus does not allow advertising. An exception is made for advertising that
is directed specifically for electronics homebuilders, and is not otherwise
available on the net in general. Examples of this are device programmers
and electronics parts. Trading between homebuilders is encouraged.
Items that fit well into other existing forsale newsgroups should not be
advertised here. PC related advertising, such as hard drives, motherboards,
and other standard PC clone parts, is not permitted. While CPU
advertisements in general are permitted, CPU advertisements for the common
PC clone CPU's (such as 486 and Pentium chips) are not permitted because of
the existing PC clone forsale groups that already provide plenty of
coverage for these parts.

2.2 Can I post questions involving hardware problems?

This question was asked to the group in general, and the overwhelming
response was NO! The only exception would be if you are having a hardware
problem with your homebuilt hardware, not pre-fab hardware. As Andrew noted
in an early version of the FAQ:

"Since EVERY SINGLE ONE of the replies I got re: the FAQ said "no, this is
not the appropriate place for questiongs about PC building and pre-made
parts and compatibility between them, the answer obviously is a very strong
NO. This is not to say that you should not post questions, but only post
questions about homebuilt computers, not computers built from pre-made
parts. The difference should be very clear. If you post here about your
hard drive that you want to slave, i doubt if people will have much mercy.
It is getting on peoples nerves."

Replies to PC hardware problems are also strongly discouraged. Such replies
should either be posted on the appropriate groups or should be done via
private e-mail.

2.3 What's this about a new homebuilt newsgroup?

It has been suggested at times (often sarcastically) that a new newsgroup
should be made up with some name other than alt.comp.hardware.homebuilt, so
that the group would not be plagued with off topic pc-clone related posts.

A newsgroup specifically for "homebuilding" in the PC clone sense of the
word (alt.comp.hardware.pc-homebuilt) has been created. All PC questions
should go to that newsgroup.

alt.comp.hardware.homedesigned was created in an attempt to provide a low
noise alternative to this group. It has since been abandoned.

2.4 What is a "Wally" (and other terms specific to this newsgroup)

   * A/D - Analog to Digital (converter)
   * ACHH - Alt.comp.hardware.homebuilt
   * a.c.h.pc-h. - alt.comp.hardware.pc-homebuilt
   * ACK - Acknowledge
   * ALU - Arithmetic Logic Unit
   * ASIC - Application Specific Integrated Circuit
   * ATA - AT Attachment (aka IDE)
   * Basic Stamp - a processor that is programmed using Basic, manufactured
     by Parallax.
   * BCD - Binary Coded Decimal
   * BIT - Binary Digit
   * BJT - Bipolar Junction Transistor
   * Bug - [1] A hardware or software error [2] An Integrated Circuit (the
     black plastic and silver "legs" look a little like an insect)
   * CAD - Computer Aided Design
   * CAE - Computer Aided Engineering
   * CCD - Charge Coupled Device
   * CISC - Complex Instruction Set Computer
   * CLK - A common abbreviation for clock (signal).
   * CMOS - Complimentary Metal Oxide Semiconductor
   * CRT - Cathode Ray Tube
   * D/A - Digital to Analog (converter)
   * Dead Bug - Non-functioning IC chip
   * DEBUG - Remove errors from hardware or software
   * DED - Dark Emitting Diode (a burnt out LED)
   * DIP - Dual Inline Package
   * DMA - Direct Memory Acccess
   * DRAM - Dynamic Random Access Memory
   * DSP - Digital Signal Processor
   * (E)EPROM - (Electrically) Erasable Programmable Read Only Memory
   * EISA - Extended Industry Standard Architecture
   * EPLD - Electronically Programmable Logic Device
   * ESD - Electro-Static Discharge
   * FD, FDD - Floppy Disk Drive
   * FDC - Floppy Disk Controller
   * FET - Field Effect Transistor
   * FP - [1] Floating Point [2] Flat Pack
   * FPGA - Field Programmable Gate Array
   * .h - An abbreviation for alt.comp.hardware.homebuilt generally used in
     conjunction with .pc-h
   * FPU - Floating Point Unit
   * GAL - Generic Array Logic
   * GaAs - Gallium Arsenide
   * GND - Ground (signal return).
   * GPIB - General Purpose Interface Bus
   * HD, HDD - Hard Disk Drive
   * HDC - Hard Disk Controller
   * HDLC - High level Data Link Control (ISO standard)
   * Homebrew - referes to the art of designing and building electronics at
     home, and has nothing at all to do with alcohol (usually).
   * IC - Integrated Circuit
   * IDE - [1] Integrated Drive Electronics [2] Integrated Developement
   * IIC, I2C, I(squared)C - often written as such since a superscript 2
     (meaning squared) cannot be displayed on an ASCII terminal.
   * I/O - Input/Output
   * IRQ - Interrupt Request
   * ISA - [1] Industry Standard Architecture [2] Instrument Society of
   * ISO - International Standards Organization
   * JFET - Junction Field Effect Transistor
   * KBD - Keyboard
   * LCD - Liquid Crystal Display
   * LED - Light Emitting Diode
   * LSI - Large Scale Integration
   * Midnight Engineering - refers to designing and building devices at
     home. Anyone who has stayed up till the wee hours of the morning
     trying to get something to work knows the origins of this term all too
   * MIPS - Millions of Instructions Per Second
   * MOS - Metal Oxide Semiconductor
   * MOSFET - Metal Oxide Semiconductor Field Effect Transistor
   * MMU - Memory Management Unit
   * MPGA - Mask Programmable Gate Array
   * MUX - Multiplexor
   * NTSC - National Television Systems Committee (Joke: Never the Same
   * PAL - Programmable Array Logic
   * PC - [1] Program Counter [2] IBM Personal Computer (or clone).
   * .pc-h - Alt.comp.hardware.pc-homebuilt
   * PCB - Printed Circuit Board
   * PCI - Peripheral Component Interconnect
   * PEEL - Programmable Electrically-Erasable Logic (ICT, inc)
   * PGA - Pin Grid Array
   * PIC - [1] a microcontroller, manufactured by Microchip. [2]
     Programmable/Priority Interrupt Controller
   * PIT - Programmable Interval Timer
   * PLA - Programmable Logic Array
   * PLD - Programmable Logic Device
   * PROM - Programmable Read Only Memory
   * PSU - Power Supply Unit
   * PSW - Program (or Processor) Status Word
   * PWB - Printed Wiring Board
   * QFP - Quad Flat Pack
   * R & D - Research and Developement
   * RAM - Random Access Memory
   * RISC - Reduced Instruction Set Computer
   * ROM - Read Only Memory
   * RX - Receiver. Often used with TX.
   * SBC - Single Board Computer
   * SCR - Silicon Controlled Rectifier
   * SDLC - Synchronous Data Link Control (IBM protocol)
   * SECAM - Sequential Color and Memory
   * Si - Silicon
   * SIMM - Single Inline Memory Module
   * SiO2 - Silicon Dioxide
   * SIP - Single Inline Package
   * SRAM - Static Random Access Memory
   * TEC - Thermo-Electric Cooler (Peltier Device)
   * TTL - Transistor-Transistor Logic
   * TX - Transmitter. Often used with RX, as in TX/RX for
   * UART (USART) - Universal Asynchronous Receiver/Transmitter (Universal
     Synchronous/Asynchronous Receiver/Transmitter)
   * UJT - Unijunction Transistor
   * UV - Ultraviolet. Typically used in reference to PROMs that are erased
     using UV light. May also refer to the erasing equipment.
   * V+/V- - Supply voltages (positive and negative)
   * Vcc -
   * Vdd -
   * VLB - VESA Local Bus
   * VLSI - Very Large Scale Integration
   * VT - Video Terminal
   * Wally - someone who posts off topic noise to the group. No offense to
     real persons named Wally is intended (the term apparantly comes from
     the TV show "Leave It To Beaver"). "Getting rid of the wallies" is a
     common thread on the newsgroup.

2.5 Where can I get an EPROM/PLD programmer?

   * Advin Systems 1050-L East Duane St. Sunnyvale, CA 94086 1-408-736-2503
   * Alta Engineering
   * Andromeda Research, PO Box 222, Milford, OH 45150 1-513-831-9708
   * BP Microsystems
   * DATA I/0 (
   * Dataman Programmers (
   * Digikey 1-800-344-4539
   * General Device Instruments, (408) 241-7376
     408-241-7376 Sales 408-241-6375 FAX
     408-983-1234 BBS All software to demo free
   * Intronics, 612 Newton Street, Edwardsville, Kansas 66111
     (913) 422-2094
     1-800-339-5152 (sales only)
   * Jason-Ranheim Company, 3105 Gayle Lane, Auburn, California 95603.
     (800) 421-7731 Orders Toll Free (800) 421-7748 From California
     (916) 878-0785.
   * JDR Microdevices Orders: 1-800-538-5000 Cust. Service: 1-800-538-5001
     1850 South 10th Street, San Jose CA 95112-4108
   * Logical Devices, 130 Capitol Drive, Golden, CO 80401 1-303-279-6868
     1-800-315-7766, tech support (in Flordia) 1-305-428-6868
   * M2L Electronics 3526 Jasmine #4 Los Angeles, CA 90034
     310 837-7818 (9am-5pm)
     BBS/FAX: 310 841 6050
   * Microchip Technology Inc 602 786 7200
     2355 W Chandler Blvd, Chandler AZ 85224
   * Mouser Electronics 1-800-346-6873
   * Needham's Electronics 1-916-924-8037 Fax: (916) 924-8065
     4630 Beloit Drive, Suite #20, Sacramento, CA 95838
     BBS: (916) 924-8094
   * Stag Micro Systems. 1600 Wyatt Dr., Santa Clara, CA 95054
   * System General
   * XELTEK unipro Universl Programmer that programs: Eproms, EEProms,
     Bipolar, Epld, Flash, Gal, Pal, and some Microcontrollers. Also tests
     3563 Ryder St. Santa Clara, CA 95051
     (408) 524-1929 (voice)
     (408) 245-7084 (fax)
     (408) 245-7082 (bbs)
   * Lists of available programmers:

Plans for making your own can be found at:

FTP sites:


WWW pages:

   * A HREF="">

PIC Programmers


PAL/GAL Programmers:


A simple eprom emulator circuit and DOS software can be found at

   * Popular Electronics, in the July 1982 issue
   * "Popular Electronics", Feb 1978, page 41
   * "Build This PLD Programmer" by Robert G. Brown
     Electronics Now (magazine), May 1994
   * Various kits and software are available from R.G. Brown, 30 Wicks
     Road, E. Northport, NY 11731
   * "Project: GAL programmer" by Manfred Nosswitz.
     Elektor Electronics (magazine), May 1992
   * "Project: GAL Programmer Upgrade" by M. Nosswitz
     Elektor Electronics, June 1993
     The software and PC boards are available through the Elektor
     publishers/franchises in various countries.

          Old Colony Sound Lab
          P.O. Box 243, Peterborough, NH  03458
          (603) 924-6371 or -6526   Fax (603) 924-9467
          In the UK
          Elektor Electronics (Publishing)
          P. O. Box 1414, Dorchester  DT2 8YH, England

   * The June '96 Elektor Electronics (UK edition). has an EPROM programmer
     and emulator
   * "Generic Array Logic (GAL)" D. Gembris
     Elektor Electronics, April 1992
   * "EPLD programmer design" John Cromie
     Electronics & Wireless World, February 1989
   * "Create Your Own IC's", Bill Green
     Popular Electronics, January 1990
   * If you have a Linux system you can design for Xilinx X3000 FPGA in a
     subset of VHDL. There is a free package named Alliance. It is
     available from, or similar sites. Fire up your search
     engine and search for ALLIANCE.
   * "A PAL Programmer" and "Getting Started with PALS" , Robert A.
     Byte, January 1987

2.6 How can I make my own SIMMS?

September 1995 issue of "Electronics Now" starting on page 35 has plans for
30 pin SIMMs

SIMM blanks may be obtained from:
In the US:

   * AutoTime Corporation
     6605 SW MacAdam Avenue, Portland, OR 97201
     (503) 452-8577
   * Memory Conversion Products,
     428 N.W. 9th Street, Corvallis, Oregon 97330-6133
     tel: 541 754-5000, fax: 541 752-8009
   * JMS Technologies, 4217C S Mellen Dr. Mountain Home, ID 83648
     FAX (208) 832-7897

In Germany:

   * eMedia GmbH, Postbox 61 01 06, 30601 Hannover, Germany
   * There are several
     versions of blank SIMM boards available from the UK including 1x1 ZIP,
     1x1 DIP, 1x4 SOJ and 1x1 SOJ.
   * Web page offering a
     number of unpopulated PCBs for making 30 and 72 pin SIMMs.

SIMM pinouts are available at

Motorola's data book - Dynamic RAMs and Memory Modules

2.7 How do I interface to an IBM clone?

   * has info on various ports
     (parallel, serial, keyboard, etc.)
   * The* FAQ (posted on news.answers and, available via ftp from contains
     connector/bus pinouts and other useful information.
   * IBM,
     Technical Reference, Personal Computer AT, 1984
   * "The IBM Personal Computer, from the Inside Out" by Sargent and
     Shoemaker (published by Addison-Wesley) provides a lot of information
     about interfacing an IBM type PC to various things.
   * Talking to a floppy control from NC4000:
   * Using a non-DOS machine to talk to a DOS disk
   * and Look up the
     datasheets for their super-IO parts, which have Paralell Port, Serial
     Port, RTC, Floppy Controller, all in one chip.
   * 16- and 32-bit DLLs for port I/O may be found at:
   * WINio.Dll and WIN32io for Windows 95
   * Accessing PC I/O ports in Windows
   * EDE300 Application Note #1: Device Control via the PC In the 'Integrated Circuits'
     section under 'EDE300'

Also, see each sub-section below.

The section "Recommended books/magazines" lists several books that may also
be helpful.

2.7a Parallel/Serial/Game Ports

Parallel Port:

* the filenames are: *lpt.faq;
ibmlpt.faq, tomlpt.faq, and krislpt.faq. each meets different skill levels
and needs.
* PC Magazine,. Oct 27, 1992 pages 367-376
* A web search for IEEE1284 (using the search engine of your choice, such
as Alta Vista) will provide numerous links.

Serial Port/Mouse:

   * "Using a serial port for discrete I/O operations" September/October
     issue of MicroComputer Journal.
   * Dallas Semiconductor has a PDF document on RS-232.
     (home page) App Note 83 Fundamentals of RS-232 Serial Communications (App Notes page)
   * National Semiconducor AN-681: PC Mouse
     Implementation Using COP800
   * --Schematic diagrams showing how
     to wire up RS232 connectors with handshaking and without, loopback
     plugs and null modem
   * MicroChip has a very nice app note on rolling your own mouse. Both the
     Microsoft and Mouse Systems versions are covered. You might have to
     read a little PIC code to find what you want, but its there. The app
     note can probably be obtained from the microchip web site. App # is

Joystick Port:


2.7b Keyboards

   * Articles about XT and AT type keyboards can be found in April/May 1995
     issues of Circuit Cellar Ink.
   * An early copy of Micro Cornucopia ( March-April 1990 ) has the details
     about standards, interface chips etc
   * John Voth has keyboard interfacing information at:
   * A PC Keyboard FAQ has been written by Mark Schultz. Send e-mail to for details.
   * Go to the Aminet site (eg. and go to hard/hack, there
     you'll find 2 or more files for PC keyboard interfaces to Amiga. There
     is some documentation for the AT keyboard protocol.
   * Check out the Philips site. There is supposed to be an app note for PC
     keyboard to serial format.

2.7c BIOS code

   * Annabooks sell a 'bioskit' that is a complete BIOS, written mostly in
     C, with source.
   * Assembler source for a V20 BIOS has been published by c't magazine
     ( The disk with the code and the burnt EPROM is
     still for sale.

2.8 How do I interface to a Mac?

   * Brian A. Cole's ( Repository of Macintosh Information
   * or (Hardware
     Descriptions and Technical Notes)
   *, follow the links "computer" "apple" "loeten am mac".
     Has information about interfaces, including a mac to VGA adaptor.
     Note: This site is in German.

2.9 Where can I find bus specs and interfacing information?

   * The VMEbus FAQ is at or
   * The I2C FAQ is available from:
   * Universal Serial Bus home page:
   * ISA pinouts can be found at
   * ISA, EISA, VLB, and PCI pinouts, signal descriptions, and timing
     information can be found at
   * "AT Bus Design, IEEE P996 Compatible", by Edward Solari ISBN
   * Official standard for the EISA bus are available from BCPR services
     (Texas) Tel: 1-713-251-4770
   * Standards for the EISA bus are available from Global Engineering
     Documents, Englewood, Colorado USA at phone: (800)854-7179,
   * The PC/104 Consortium has a page at
     Request a resource guide and spec document.
   * The PCI specification may be obtained from: PCI Special Interest Group
     P.O. Box 14070, Portland, OR 97214
     (800) 433-5177 (503) 797-4207 FAX: 234-6762
     (503) 797 4297
   * Other PCI information:
   * AMCC makes a chip which provides an interface to PCI on one side and a
     fairly simple generic interface on the other side. AMCC is in San
     Diego, California. Their telephone number is (619)450-9333. The part
     number for the PCI interface chip is S5933.
   * Ziatech, has the CompactPCI spec in Acrobat.
     CompactPCI uses the PCI timing and pinout with a eurocard format and
   * D Prutchi, "Hot Swapping on the PC - An Active Extender Card for the
     16-bit PC-ISA bus", Circuit Cellar Ink, Issue #62, 62-71, September
   * PCMCIA specs are available from (not free) The
     PCMCIA association lists manufacturers with links to webpages, also
     links to books.

2.10 Where can I get hard/floppy drive specs and interfacing info?

(IDE is also known as ATA)

   * Information on ATA 1,2,3 can be found at
     Technical information about Seagate drives may be found at
     Western Digital technical support 1-800-275-4932
     See the ATAr4c.txt and ide-tech.txt files for more info.
   * "Yet Another Enhanced IDE/Fast-ATA/ATA-2 FAQ" is posted on and .misc. It is also available,
     together with related material, by FTP from
     and by WWW from:

   * Enhanced IDE FAQ
   * For a complete treatment of IDE interfacing to 8-bit CPUs
     (particularly the Z80 family), check out issues 56, 63, 64, and 66 of
     The Computer Journal.
   * There is a simple IDE interface for the Z80 called GIDE (Generic IDE).
     It should be possible to adapt it to other 8-bit processors. There is
     an article about it on the TCJ Web Page. Click on 'GIDE'.
   * Connecting IDE devices to 8 bit machines:
   * SCSI:

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