{PowerGlove FAQ}

Forward

Mattel PowerGlove FAQ version 0.3, [date].

Written by jet@well.sf.ca.us (j. eric townsend).

Significant help and input from:

Randy Shedden (randysh@microsoft.com), Linda Jacobson (lindaj@well.sf.ca.us),lots of people on the WELL, sci.virtual-worlds, and of course, the glove-list.

The FAQ is still in a very rough state. Please send changes/adds/deletes to jet@well.sf.ca.us.

All sorts of product names are probably trademark by the appropriate vendors.

Comments in the form of [DO YOU UNDERSTAND THIS? -JET] are notes to myself, let me know if you have something to replace the note with.

A current version of this file can be obtained from ~jet/public on the WELL or netcom. It will also be posted to USENET's sci.virtual-worlds, the WELL's vr conference and various mailing lists at sporadic intervals.

If you are reading this via a World Wide Web (WWW) client here might be an interesting place.

This is probably the last version of the PowerGlove-specific FAQ. It will probably be consumed by a HomeBrew VR FAQ, if things go well. (I recently (Jul 94) changed jobs. Much of my free time is consumed with work here at General Magic, Inc., making the world a safer place for personal communicators.)

DISCLAIMER

This document does not constitute an endorsement of any of the products, services or groups listed.

It's not my fault if you get hurt, suffer loses, or get into trouble because of anything you read in this document.

Please read the distribution restrictions in the Introduction.

Introduction

This document assumes you have a basic familiarity with the terms and concepts related to virtual reality and also with USENET and the Internet with its related tools (telnet, ftp, mail).

This document is written in TeXinfo, which means it is equally easy to read in source form or print out a nicely formatted copy. But wait, there's more! You could convince your site admin to install the powerglove faq into the emacs info database, and read it with emacs info or xinfo! If you don't want/can't info or print this document, you'll be able to read through with little, if any, difficulty. (For more information on texinfo, poke around in GNU emacs or ftp the texinfo package from /pub/gnu on prep.ai.mit.edu.)

This document is copyrighted by J. Eric Townsend as documented on the opening pages and cover. Permission is given to non-profit corporations to redistribute this document in electronic or printed form as long as the document is distributed in its entirety. Permission is given to online services such as the WELL, Mindvox, and others to store this document for distribution to subscribers only if equal access to this document is provided to non-subscribers. (See the WELL's gopher server for an example, where this document can be accessed by gopher from systems the WELL does not own or control.) Permission is also given for USENET sites to redistribute this document to other USENET sites.

Any for-profit distribution of this document is strictly prohibited, including CD-ROM compilations or inclusion in any other published work where a fee is charged.

What is a PowerGlove?

In 1989 Mattel (yes, the toy company) introduced the PowerGlove, a handtracking device based on a glove. The PowerGlove was intended to work with the Nintendo Entertainment System (NES) in place of a regular controller. The PowerGlove can track motion of the glove in three-space, finger position, and has a set of buttons/switches on the top of the wrist.

It has two modes "hires" and "lores". In "hires" mode, the PG reports the position in threespace, the roll, and configuration of fingers along with the SELECT, START, A, B, CENTER and ARROW CLUSTER switches (which are a part of the NES standard controller). In lores mode the glove reports position on the hand on the x and y axis and the buttons (thus emulating a NES controller completely and allowing one to use the glove with non-glove-specific games).

The lores mode also allows the users to select one of fourteen (?) built-in programs that associate different sets of motions with the NES controller outputs of up/down/left/right/select/start/A/B. Each program also has its own translation of finger movements to control inputs.

Why use a PowerGlove instead of <foo>glove

PowerGloves originally cost around $100, if you're lucky these days you can find them usually under $30 at a Toys R' Us on the remaindered rack. Most of the gloves on the shelves have been bought up, some by speculators. (I keep hearing rumors of people with 40-50 gloves in a closet who trickle them out a few at a time.) If you don't know what a Dataglove costs, you probably can't afford it.

What are the big problems?

Several problems face you if you want to use a PowerGlove as a VR input device. These aren't technical problems (although there are those as well), mind you, but real-world problems.

There is no official hardware or software support from Mattel, and the gloves are no longer being produced. Of course, there is no official hardware or software support from any third party companies either.

Contact Nintendo for information if you like, but the person who answers the phone probably won't even know what a PowerGlove is.

On the up side, everything you will use was probably written or designed by a fellow hacker.

What are the technical problems?

The ultrasonic sensing is done with inexpensive microphones so it is difficult to place the sensing array directly on a computer monitor and get a clean signal. A somewhat common fix is to hang the sensing "array" on a wall that has a low ultrasonic reflection rate. People are using anything from towels to ultrasonic anechoic foam to dampen the noise.

This detailed list of problems is from Randy Shedden:

  1. In order register your hand position, you must point your knuckles at the receiver array. It gets tiring holding your hand up for extended periods.

  2. The only information about hand orientation that get is rotation. (This is also called roll.) In flight technology, if you raise one wing while you lower the other, this is called rolling the plane. Ascribing this behavior to your hand, if you raise your little finger while lowering your thumb, this would also be called roll. If a plane moves it's nose to the left while the tail moves to the right, the plane is said to yaw. If you do the same thing with your hand, the ultrasonic transmitters would point away from the sensor array and you would lose all orientation information. If a plane lowers it's nose while the tail is raised, the plane is said to pitch. If you do the same thing with your hand, again you lose all orientation information. So, while the VPL DataGlove can track yawl, pitch and roll. The PG can only track roll (commonly called rotation).

  3. The information about how your hand is configured is not very accurate. As mentioned above, the material that covers the thumb and fingers has different electrical resistance depending on how much it is flexed. So, when you have a finger fully extended, the material is not flexed at all. When you have a finger fully clenched, the material is flexed to it's functional limits. This is expressed in terms of a degree of flexure (bentness) for each digit. This degree is one of 4 integer values.

    0 means the digit is fully extended.

    1 means the digit is a little bent

    2 means the digit is more bent than straight and

    3 means the digit is fully bent.

  4. For each digit, this resolution isn't very good. Aside from that, it is hard to flex the material to reproduce the desire degree of flexature. For instance, it is not a trivial matter to do a gesture that requires that the ring finger be at state 1 (a little bent). This digital (no pun intended) value is also hard to maintain once you have it, because moving the neighboring digits can have an effect on the flexure of the digit in question. Try bending your middle finger without also bending your ring finger. Additionally, Only the thumb and THREE of your fingers are tracked at all. For some reason, the PG doesn't keep track of your pinky. In comparison, the VPL DataGlove gives much better resolution on ALL of your digits and material (a small fiber optic cable) is much easier to use than the bulky PG material.

Resources

If you are interested in the various mailing lists, you'll want to grab the canonical list of mailing lists from news.answers on USENET. (Or, failing that, from the author arielle@taronga.com. Don't bother her unless you need to, she's very busy and too nice to bother with trivial problems.)

The PowerGlove mailing list

The PowerGlove mailing list is dead. (It fell on its head.)

Modulo buying/selling used gloves, there was no glove-related traffic. I'll attempt to put *every* bit of knowledge in this and future versions of the FAQ. Once I've cleaned out the huge amount of crud from the archives, I'll put a condensed version of them out for FTP. (The raw archives will be available for those masochists who want to do a statistical analysis of "unsubscribe me from this list" messages from various domains.)

sci.virtual-worlds (sci.v-r)

(From Bob Jacobson, past moderator of sci.v-r and the current moderating staff.)

sci.virtual-worlds and its sibling, sci.virtual-worlds.apps, are newsgroups on the USENET covering developments in the field of virtual worlds technology and applications, respectively. These newsgroups, now three years old, serve an international community of over 15,000 regular participants with news, technology highlights and developments, scientific and philosophical issues, and discussions of how virtual worlds (also known as "virtual reality") are or will be used in various commercial and social settings.

Newsgroup submissions should be sent to: <scivw@hitl.washington.edu> Questions or comments should be sent to: <scivw-request@hitl.washington.edu>

The sci.virtual-worlds Moderating Group:

MICHAEL ALMQUIST <squish@hitl.washington.edu> - Michael Almquist (aka. "squish") has been hanging out at the HITLab for over two years now after obtaining a BS in Computer Science.

TONI EMERSON <temerson@hitl.washington.edu> - Toni is Coordinator of the HITL Knowledge Base Project and Manager of the sci.virtual-worlds Moderating Group.

DANIEL PIRONE <cocteau@hitl.washington.edu> - Daniel Pirone has a BS in Computer & Information Science. He is a HITL staff member, part of the Software Group.

JERRY PROTHERO <prothero@hitl.washington.edu> - Jerry is a Research Assistant at the HITLab, currently finishing his master's in Industrial Engineering.

AARON KALEVA PULKKA <pulkka@cs> - Aaron earned his B.S. in Computer Engineering at the University of Washington, where he is currently pursuing a Ph.D. in Computer Science & Engineering.

MARK TAKACS <tak@hitl.washington.edu> - Mark has just finished his master's thesis (Prolix: A text based participant system for VR) and spends more time than he can spare exploring the internet and programming Muds.

A mailing list is kept by Prof. Greg Newby at the University of Illinois for those who cannot directly access s.v-w and s.v-w.a via the USENET. Requests to be added to this list should be sent to:

gbnewby@uxh.cso.uiuc.edu

This is not an automatic operation; please be patient while Greg makes the necessary additions.

The newsgroups are also featured on CompuServe, in the Arts Section, in abbreviated form; excerpts also appear on GEnie, BIX, and the WELL (in its vr conference). Welcome!

The FAQ for s.v-w is at ftp.u.washington.edu, ./public/virtual-worlds/Meta-FAQ. The FAQ is posted monthly on the 13th.

VRASP

VRASP is an organization that you probably want to belong to. They are putting out quality information at a reasonable cost. Plus, it's tax deductible. (e-flyer courtesy of Mark Pflaging.)

VRASP

The Virtual Reality Alliance of Students and Professionals is a support network and educational forum dedicated to increasing public knowledge of virtual reality applications, and to furthering the development of VR technology as a whole. Our membership is global and diverse, and includes both lay- and professional programmers, researchers, inventors, graphic artists, writers, promoters, film-makers and philosophers.

We are presently functioning as a resource bank and referral network for those seeking information on VR and the VR community, distributing research and development findings as well as product and promotional information. We hold our own educationally-oriented meetings and events at which VRASP members get to socialize "ftf", sharing their eclectic knowledge and cooperatively pursuing a future where Virtual Reality is a Reality.

We are also the publishers of "PIX-Elation"; a bi-monthly 'zine featuring product surveys, event and convention reviews, lecture transcriptions, scanned and rendered graphics, an industry networking page and a calendar of upcoming industry events, as well as interviews with leading researchers, groundbreaking artists, and proponents of "homebrew" VR. "PIX" is written primarily by VRASP members, all of whom are invited to submit their articles, graphics, and findings.

MEMBERSHIP Individual member dues are $30 per year inside the US. All other countries: $40. This includes bimonthly issues of PIX-Elation, regular admission to VRASP Chats and discounts at VRASP lectures and workshops. For special Business and Institutional Member Rates, please contact us.

Volunteerism is strongly encouraged and will be rewarded by a special "Contributing Member" designation. This status will entitle you to special privileges, such as networking opportunities and the ability to hold office in the organization, as well as public acknowledgment in the newsletter and at conferences.

CONTACT INFORMATION:

Karin August President, VRASP Publisher, PIX-Elation PO Box 4139 Highland Park, NJ 08904-4139 Voice: (908) 463-VRVR Fax: (908) 580-0092 Internet: kaugust@caip.rutgers.edu

Tod Foley Director, VRASP Senior Editor, PIX-Elation 8055 Wakefield Ave Panorama City, CA 91402 Voice: (818) 786-6318 Fax/Modem: call to arrange

Internet: asif@well.sf.ca.us random@cyberden.sf.ca.us random@phantom.com

Amiga and VR mailing list

Ethan Dicks has set up a discussion list for topics related to using the Amiga for VR. To subscribe, send mail to amigavr-list-request@kumiss.cmhnet.org.

trackers mailing list

The trackers list usually covers 3d-related issues. Requests go to trackers-request@qucis.queensu.ca. [1NOV93 I recieved email that this list is dead. Anyone confirm/deny? -eric]

WTK list

From Terry Fong:

The WorldToolKit Users' Group is intended to provide a contact point for users of Sense8 Corp.'s "WorldToolKit" to discuss and exchange information on a variety of topics. Among these are:

The group has a mailing list which forwards email messages: sig-wtk@ptolemy.arc.nasa.gov. Anyone interested in joining the sig-wtk list should send email to: terry@ptolemy.arc.nasa.gov

Terry Fong NASA Ames Research Center

REND386 mailing list

REND386 mailing list. rend386 is a great rendering package for the 386, PG can be used as an input device (@pxref {REND386}).

Contact: rend386-request@sunee.uwaterloo.ca

ftp sites

A good FTP site for general VR information is ftp.u.washington.edu:/pub/user-supported/virtual-worlds. This site is maintained by the folks who do sci.v-r on usenet.

schmidt@cogsci.uwo.ca has offered the use of cogsci.uwo.ca as a PowerGlove related ftp site. Check: /pub/vr for a variety of glove-list related stuff.

Someone at Apple has started a VR section at ftp.apple.com:/pub/VR. This site contains Jon Blossom's Gossamer along with other goodies for the Apple Mac.

Please note that karazm.math.uh.edu is no longer the PowerGlove ftp site.

PCVR Magazine

From the PCVR electronic flyer:

PCVR, a new Virtual Reality publication, introduces high-tech Virtual Reality equipment, theories, and software to the layperson by simplifying procedures, languages, and materials. The equipment necessary for a Virtual Reality system usually costs over $25,000 and is primarily available to universities and businesses. PCVR changes this situation by bringing the technology into the home through tutorials and do-it-yourself projects. Through step-by-step articles, a complete Virtual Reality system can be built for under $3000 including the personal computer necessary to execute the system.

For $26 a year, subscribers receive 6 issues which contain; editorials, thought-provoking columns, hardware/software topics, tutorials, and do-it-yourself projects. We also include a disk as a convenience to the reader, which contains all the software discussed in the articles.

The hardware projects have covered connecting the Sega 3D glasses and Mattel Powerglove to an IBM personal computer, building a head mounted display, and constructing a head tracker device. These do-it-yourself projects use off-the-shelf components which enables a non-technical person access to Virtual Reality equipment in their own home.

The tutorials explain the major technical areas of Virtual Reality without the jargon usually associated with industry journals.

PCVR intends to bring Virtual Reality out of science laboratories and into the general computer community.

Subscription Information (6 Issues): $26.00 US/Canada, $38.00 Overseas. Back Issues- All Are Available 1-9: $4.50 US/Canada, $6.50 Overseas Payment: Check or Money Order drawn on US bank in US dollars. VISA, Mastercard and American Express

Issue Themes:

PCVR can be contacted at: PCVR; PO Box 475; Stoughton, WI 53589; Phone/FAX: (608) 877 - 0909; EMAIL: pcvr@fullfeed.com

Other Power Glove people / Previous Works

This is sort of a history, I'm not sure of the exact order, but the facts are sort of correct.

First, there's the history of the PowerGlove itself. Rich Gold, in CyberArts writes: [INSERT TEXT FROM CYBERARTS]

Hardware Interfaces

AGE box

AGE built a serial interface device and sold them to a few universities. They aren't generally available and have an almost mythical status.

Gold Brick

Many users on the glove-list have used this box. Charlie S.Lindahl (lindahl@cse.uta.edu) comments:

I have done a lot of hacking around with the Transfinite Systems box on the Mac. Two points:

  1. The PG sample code which comes with the box is not great (stylistically) and is written in MPW C. After much struggling I finally managed to extract the position sensing code into a standalone THINK C program.

  2. As it currently stands, the TRANSFINITE stuff only works consistently with system 6 of the MacOS. It DOES work with system 7, if you turn off 32-bit addressing and virtual memory. I've coaxed the assembly source code for the GOLDBRICK driver from Transfinite to try to port to sys7, but haven't had the time to hack it out yet.

This information is taken from a flyer from Transfinite:

GOLDBRICK: The Cyperspace Interface (tm)

Summary: The Gold Brick (tm) is a device that connects the Apple Destop Buss (tm) to most controllers compatible with and to the Nintendo Entertainment System (tm). It allows you input from Broderbund UFORCE (tm), floor pad input from the Nintendo Power Pad(tm), tilt sensing with the Enteractive (tm) Roll&Rocker(tm), and POSITION SENSING WITH THE MATTEL POWER GLOVE (tm).

With Macintosh support software (system 6.0.5 or later), Gold Brick can translate controller input into 2 or 3 dimensional motion and/or keystores as specified by the user.

The controller and game deck interfaces are generally compatible with those of the Motorola SPI, National Semiconductor Microwire (R), and Signetics I2C type.

According to the manufacturer the Gold Brick is already being used in the following systems: - controlling intractive multi-media - playing virtual instruments - giving audio feedback to speech-impaired infants - allowing viewers to walk through computer-deisgn structures - transforming inputs on a power pad to English sentences and music

There are a number of models available depending on your needs and budget. They are summarized as follows:

THE GOLD BRICK COMPARISON CHART:

                        MODEL 1                         MODEL 2

                    | Release 1 (1) | Release 2     | Release 1    |
--------------------|---------------|---------------|--------------|
Part Number, Retail | GBC-1, $195   | GBC-2, $245   | GBN-1, $169  |
--------------------+---------------+---------------+--------------|
Controllers support |               |               |              |
 * Standard         | Yes           | Yes           | Yes          |
 * Power Pad        | Yes           | Yes           | Yes          |
 * "Unknown" type   | Yes           | Yes           | Yes          |
 * UFORCE           | Yes           | Yes           | Yes          |
 * POWER GLOVE      | No            | YES           | YES          |
--------------------+---------------+---------------+--------------|
Status Lights       | Three         | Three         | None         |
--------------------+---------------+---------------+--------------|
ADB Through port (2)| Yes           | Yes           | No           |
--------------------+---------------+---------------+--------------|
Game Deck Cable     | Yes           | Yes           | No           |
--------------------+---------------+---------------+--------------|
Technical Manual (3)| Yes           | Yes           | No           |
--------------------+---------------+---------------+--------------|
Upgradeable (4)     | Yes           | Yes           | No           |
--------------------------------------------------------------------


Footnotes:
(1) No longer available
(2) Permits additional apple desktop bus devices to be attatched
(3) Limited tech. doc. was included in GBC-1. A software tech. manual
    (REF-1), available separately, is included in GBC-2
(4) Uses a socketed single chip microprocessor that can be replaced with
    later versions.

ORDERING INFORMATION: Transfinite Systems Company, Inc.; PO BOX N, MIT Branch Post Office; Cambridge, MA 02139, USA; Tel: (617) 969-9570; Applelink: D2002

Menelli box

Ron Menelli built a 68HC11-based box that duplicates the AGE box. The schematics and code available via ftp at cogsci. They are available from the glove-list archive server as pg-hc11.zoo and pg-hc11.tar.Z.

Several problems exist with building this box: 68HC11's aren't easy to come buy unless you're ordering a few thousand and two of the parts for the Menelli box will *not* be found a Radio Shack or Fry's, one will have to go mail order to some place such as DigiKey.

PGSI

The PGSI (PowerGlove Serial Interface) is a project from UIUC and promises to be the bestest cheapest way to use the PowerGlove with nearly any computer. The PGSI FAQ is maintained by Ben Gross (pgsi@uiuc.edu) and can be ftp'd from FTP.cso.uiuc.edu (128.174.5.59) in /ACM/PGSI as PGSI.FAQ. Like most FAQs, it is irregularly posted to various newsgroups and mailing lists.

The first batch of orders were shipped in mid 1993. There is talk of another production run, the PGSI FAQ should be checked for the latest data.

Software

[IF YOU'RE USING A SPECIFIC PACKAGE, AND HAVE COMMENTS, LET ME KNOW. -JET]

Amiga Software

The Amiga has the worst software selection at this time. There are only a handful of basic packages for getting glove data into the Amiga via the parallel port. Both packages work only on the A500/A2000 units. The author strongly advises anyone interested in doing glove-work on the Amiga to go to a serial-port based device such as the PGSI.

'amigahires.lzh' contains code to drive the glove in hires mode and grab packets from the parallel port.

'gt.lzh' contains code to grab data from a glove attached to a parallel port and dumps it out a port. Whiles this is The Right Way to do things on an Amiga, the code only runs correctly on 68000 based machines.

'glovetest.lha' (also 'gt.lzh') is a useful diagnostic tool that includes the above gt.

Mac Software

Jon Blossom's 'gossamer' package is available from ftp.apple.com.

The "Max" package for the Mac has support for the Gold Brick. It is a development environment, so you will have to write code that translates glove movements into the actions you want from Max. Max is produced by Opcode, opcode@well.sf.ca.us.

PC Software

O2GLOVE is a set of sources from VRASP ([CROSS REFERENCE]) to help you write your own PowerGlove applications for the PC.

REND386 is a PC-based rendering library that supports the PG. Demo available by FTP from sunee.uwaterloo.ca:/pub/rend386/demo4.zip Source/developer's kit in /pub/rend386/devel4.zip

O2GLOVE is well suited for serious glove use and programming. If you are more interested in producing VR environments and less interested in programming, REND386 is probably the way to go.

REND386

From the rend386 distribution:

REND386 -- A 3-D Polygon Rendering Package for the 386 and 486 Written by Dave Stampe and Bernie Roehl

DEMO4 Documentation Version 4.10 - August 1992

This document describes how to use the new REND386 demo, called "demo4.exe".

To run the demo, just type "demo4" or "demo4 filename" where 'filename' is the name of a .plg file, a .fig file, or a .wld file you want to have loaded.

The demo4.exe program is designed to illustrate some of the capabilities of REND386, a polygon rendering library for 386 and 486 systems with VGA displays.

The libraries are available for free; the only reason for making the demo a separate set of files is to give people who aren't interested in writing software a chance to see just what can be done on widely-available hardware.

The system is fast. How fast, you ask? Well, speed is not a straightforward thing to measure. There is a relationship between the speed of the processor, the complexity of the scene, and the number of frames per second.

With this software, a 512-polygon scene can be rendered at speeds up to 15 frames/second on a 486/25; this corresponds to a speed of over 7000 polys/second. If you have a 486/33, it'll go slightly faster; if you have a 386/33, it'll go slightly slower. You get the idea. If you want more frames/second, use a simpler scene (i.e. fewer polygons).

To use this demo, you MUST have a 386 or 486; it will not run at all on a 286 or below. You must also have a standard VGA display.

This version now support stereoscopic viewing; the assumption is that you have the Sega 3D glasses and the interface described in sega.txt installed.

O2GLOVE

From the O2GLOVE distribution:

Object Glove is an object oriented driver for Mattel's Nintendo Power Glove connected to the parallel port of a PC. It is written in C++ for Borland C++ 3.1. The code has many features that make it accessible, extensible, and easy to incorporate into existing applications. First, it runs on a wide variety of PCs, from '286s to '486s, without modification. Second, it is interrupt driven, which means the sampling takes place at regular intervals without requiring any attention from the application program. Thirdly, the programming interface is extremely simple. Since the program is object oriented, any future improvements to the driver would be transparent to the applications that use it. More advanced processing of the glove input can be handled by deriving classes from the main driver class. Lastly, the code is Windows compatible.

Object Glove supports the simultaneous use of two gloves. (Support for more gloves is possible but not planned.) Object Glove is the only publicly available product with this capability.

There are several programs that make use of Object Glove. Included is a demo program that displays a line drawing of a hand. The hand moves around on the screen based on the movements of the Power Glove. There are two versions of the demo program, one for DOS and one for Windows. In the DOS version, user definable gestures are displayed on the screen when they are recognized. In the Windows version, gesture recognition can be associated with system sounds. These sounds are played through the Windows 3.1 Multimedia Interface, thus the sounds are also user-definable. Also, a version of Rend386 has been included that utilizes Object Glove. Rend386 is a freeware "virtual reality" program that allows navigation though a three dimensional world. Rend386 is customizable and allows the creation of new virtual worlds. Rend386 was written by Dave Stampe and Bernie Roehl.

Court Jesture, supplied with Object Glove, is a gesture recognition system. It operates in real time, allows definition of gestures by the end user, and dispenses the gestures selectively to application objects in an object-oriented way. Gestures can be grouped into "sets" and gesture sets can be activated and deactivated dynamically by the application. When two gloves are used, each glove can have separate gesture sets or the same gesture sets. As with Object Glove, it works under DOS and Windows and has been combined with Rend386.

Summary of features:

This product is available through VRASP, the Virtual Reality Alliance of Students and Professionals. VRASP also has Power Gloves, PC-to-Power Glove connectors, and other low-cost Virtual Reality items for sale. VRASP is a non-profit, educational organization devised to increase public knowledge of virtual reality and further the development of VR technology. Membership in VRASP includes six issues of our popular newsletter Pix-Elation, containing a wealth of "inside" VR information and insightful articles.

A comprehensive demo program is available on the Internet. The demo includes DOS and Windows executables, and a version of Rend386 that supports two gloves and gesture recognition. You can use glove gestures to fly around in worlds. The demo also includes a Windows program to move the "mouse" cursor with a glove. Instructions for building a one or two glove connector are included. Some sample source code is included, but in order to fully compile the demo programs you need to buy the library. To get the demo program, anonymous FTP as follows: Host name: sunee.uwaterloo.ca Directory: /pub/glove File name: objglv.exe The file is a self-extracting archive. It is advisable to transfer this file in the evening when net traffic is low. Make sure to use BINARY mode!

Unix

With the general availability of the PGSI, we'll probably see more codes for the PowerGlove on UNIX platforms. There exist a couple of packages for older NeXT computers and SGI's, but they require more hardware than just a serial port.

Getting Started

With any platform, your basic steps are going to be:

  1. Figure out what platform you're going to use.
  2. Decide which interface for the glove you're going to use and what software. Your choices might be limited due to the platform you're using, your programming skills, and available hardware.
  3. Plug everything together.

This section is intended for rough instructions for various platforms. It's going to be empty the longest, simply because I don't have access to lots of different hardware. If you'd like to submit some guidelines/instructions for a specific platform, feel free.

Amiga Setup

options:

Mac Setup

PC Setup

whole list of possibilities:

Unix Box Setup

Related homebrew stuff

PowerGlove NES games

The following games were produced for use with the PowerGlove on the NES: Bad Street Brawler, Glove Pilot, SuperGloveBall, Manipulator, Maze Ball. SuperGloveBall is supposedly the game to have for the 8bit NES.

Sega glasses

Sega had a game that competed with the NES called "Sega Master system". One of the neat doodads Sega made was a set of LCD shutter glasses, similar to Haitex goggles (and the shutter glasses many SGI visualization tools support). They are discontinued, and don't seem to be in most stores. SEGA used to sell refurbished units, but they're out as well.

Toshiba goggles

supposedly better than sega. [FIND OUT FROM alt.3d?]

UForce controller

Broderbund makes/sells a NES-controller compatible 3space sensor. Two plates at right angles contain a set of infrared emitters and detectors. It has an NES-controller-mode and (yet another) "analog" mode. No one has decoded the analog information and made it available to the net. The UForce is currently available.

This is Ethan Dicks' UForce FAQ:

Ethan Dicks <erd@kumiss.cmhnet.org> Version 1.0 24-Mar-1992

"Uforce 101..."

The Uforce has 9 total IR emitters and detectors of which 8 may be active at any given time. The four configuration switches are divided into two functional groups. The first three select a sample mode which determines how the Uforce will present the data to the host and the last switch selects which of two particular sensors is active. Seven of the eight possible arrangements of the first three config switches places the Uforce into "Threshold mode" wherin the device compares the values of the various sensors against known thresholds in ROM and provides the host with a standard NES 8 bit packet containing up/down/left/right/select/start/A/B information. When all three switches are down, the Uforce is placed into "Analog mode" wherin a multi-byte packet with raw information about each IR sensor is provided to the host. The format is as follows... (all values in hex)

 Flag      S 7     S 6     S 5     S 4     S 3     S 2      S 1     S 0
FC-FF*    01-FB    01-FB    01-FB    01-FB    01-FB    01-FB    01-FB    01-FB

FF = no buttons pressed
FE = START pressed
FD = SELECT pressed
FC = START & SELECT pressed

The flag byte is easy to spot because it is always over FC. If 00 is ever read, it should be discarded because the Uforce is still aquiring data (this can take up to 10 milliseconds to complete); 00 is never valid data. There must be a 150 microsecond delay between bytes; this is an NES restriction. Any routine which is able to read in a single byte from a standard NES controller can be used to read the Uforce in Analog mode; unlike the PowerGlove in hires mode, the Uforce uses fairly standard techniques for sending data back to the host.

The sensor map is arranged as follows...

    +------ 0 ------+
    |   2       1   |
    |               |
    |   3       5   |
    +---------------+
    |   4           |
    |               |
    |   7       6   |
    +------ 5 ------+

Sensor 5 is controlled by the right most config switch (#4)

Supplies/Mail Order

Hacking PowerGloves requires access to information and supplies that aren't found in obvious locations.

Scrounging

Scrounging is probably your best bet for things like PowerGloves, UForces controllers, and other goodies. The San Francisco bay area and greater Houston areas each sport one or more computer junk stores. In San Jose, try "Wierd Stuff Warehouse" and "HalTed Electronics". In Houston, try "EDS", on the west side.

Generic resale/thirft shops such as Salvation Army aren't always worth the trouble, as they tend to toss things out that they can't obviously test or that have no obvious function. They're also wise to corporations trying to 'donate' broken junk. Good place to get clothes to be cut up and modified for input gear.

Garage sales are another big win. I was having horrible luck finding anything other than broken lawn furniture until a neighbor explained the 'right way' to garage sale: check ads in the paper the day before, start early enough that you hit several sales as they start and remember that you can probably talk down people on their prices. Most importantly, don't let on that the PowerGlove they're asking $10 for usually goes for more than $30.

If nothing else, it won't hurt to post to sci.v-r, the glove-list or related groups your "want list".

Mail Order

DigiKey (XXX-XXX-XXXX) is a popular mail-order house with many homebrew folks. They stock a large selection of components and whatnot. [ANYONE HAVE THEIR NUMBER HANDY? -ERIC]

FringeWare does mailorder of lots of stuff. [INSERT REFERENCE. -ERIC]

Nintendo extension cables are available from MCM Electronics; 650 Congress Park Drive; Dayton, Ohio; 45459-9955; 800.543.4330. The cable is called a "Nintendo Type Joystick Extension Cable", part# 83-0325.

If you're short an L-bar, you can order one from Mattel: Mattel Toys; 7676 Reinhold Road; Cincinatti, OH; 45237.

Stores

Fry's is a large chain of stores that try to be to electronics what supermarkets are to food. Fry's in the SF Bay area usually carry: Macs, PCs, EO's, Newtons, Zoomers, home entertainment, electronic components, tools, software, magazines, personal hygene supplies and junk food. (Great prices on soda by the case.)

Radio Shack is still in business, regardless of their best attempts to do otherwise. Their prices are outrageous compared to larger PC chains like Fry's, even for things like a handful of resistors. They'll do anything to get your name and address so they can kill trees to send you ads for stuff you don't want. Don't bother with Radio Shack unless you have no other choice.

Feel free to submit information on your local electronics supplier.

Wierd Info, Trivia, References

Time to get obscure. Thanks to all who provided information and ideas.

The PG was designed by Chris Gentile (the "G" of AGE) and someone named "Novak" at Mattel. If you meet either of them, do whatever it takes to ply their brains for all the information you can get.

The finger sensors are made by Amtec International 3653 West 1987 South Salt Lake City, UT 84104 USA Tel. (801) 977-0359

PowerGloves are becoming hard to find. You might want to try looking at Toys R' Us immediately, but you're probably too late. After that, hit any chain that ever sold Nintendo gear (see section Supplies/Mail Order).

The coolest thing thus far is the original, official, PowerGlove carrying case. Found for around $12 (half what a glove usually costs) at a Toys R' Us in Los Angeles area.

References

A variety of references on PowerGloves and homebrew VR. If you have more to add, or corrections, please submit. (Also, if you know a good way to use BiBTeX with texinfo, let me know that as well.)

A whole slew of homebrew-style VR books have hit the shelves from mass-market publixhers (like Sams). I hope to have some references for these in the next version of the FAQ.


- Gardner, Dana L.  "The Power Glove", Design News. 4-Dec-89 pp63-68
  (history of design and marketing of the PG, not very technical.)

- Jacobson, Linda. _CyberArts_ [COMPLETE CITATION]

- Jacobson, Linda. (new book on garage VR)

- Pausch, R.  "Virtual Reality on Five Dollars a Day". 
  Proceedings of ACM SIGCHI Human Factors in Computer Systems
  Conference, New Orleans April 1991. Text file might be available for
  FTP from HITL: milton.u.washington.edu, in /public/virtual-worlds/papers

- "VPL Virtually Gone. (VPL Research loses control of its patents to
  Thomson CSF)", MacUser.  March, 1993, v9(n3). p45(1).

- Zimmerman, Thomas G. et al.  "A Hand Gesture Interface Device".
  Proceedings of CHI+GI '87, ACM 1987. pp190-192.
  (really about the prototype of the DataGlove, but also discusses
  a cheaper "Z-Glove" [Zimmerman Glove?] that used ultrasonics for
  tracking and was used with a CBM64 computer.  Probably the "original" PG.)

- Zimmerman, Thomas G and Lanier, Jaron Z.  "Computer Data Entry and
  Manipulation Apparatus and Method", VPL Research Inc.
  US Patent 4,988,981.  Redwood City, CA (USA). Jan 29 1991.
     
- Zimmerman, Thomas G.  "Optical Flex Sensor", Sept 17 1985
  US Patent 4,542,291

Legal Issues

THE AUTHOR IS NOT A LAYWER. THIS IS NOT LEGAL ADVICE.

That being said, there's not much you have to worry about while hacking the PowerGlove. As long as you use other people's software with respect to their copyright and licensing agreement and give people credit where it's due, you should be in the clear legally.

If you decide, however, to build stuff from scratch, you should be aware of existing patents on hardware/software.

Patents

It is the personal opinion of the author that vaguely stated patents covering broad areas hinder the virutal reality industry more than help it. That being said, the following are some important patents you should take a look at.

In particular, VPL (or whomever owns them this week) owns a patent covering the 'manipulation of virtual objects in a computer system' (see below).

VPL sued Jim Kramer of Virtual Technologies over a glove input device that competed with the DataGlove. VPL lost the suit and Virtual Technologies continues to produce their gloves. (The author does not know why the suit was lost, if VPL retracted, or the current status of the patent.)

Selected patents:

League for Programming Freedom

The League for Programming Freedom is dedicated to ending software patents and user interface copyrights. They have lots of docs here. The following is from one of their electronic fliers:

Ten years ago, programmers were allowed to write programs using all the techniques they knew, and providing whatever features they felt were useful. This is no longer the case. New monopolies, known as software patents and interface copyrights, have taken away our freedom of expression and our ability to do a good job.

"Look and feel" lawsuits attempt to monopolize well-known command languages; some have succeeded. Copyrights on command languages enforce gratuitous incompatibility, close opportunities for competition, and stifle incremental improvements.

Software patents are even more dangerous; they make every design decision in the development of a program carry a risk of a lawsuit, with draconian pretrial seizure. It is difficult and expensive to find out whether the techniques you consider using are patented; it is impossible to find out whether they will be patented in the future.

The League for Programming Freedom is a grass-roots organization of professors, students, businessmen, programmers and users dedicated to bringing back the freedom to write programs. The League is not opposed to the legal system that Congress intended--copyright on individual programs. Our aim is to reverse the recent changes made by judges in response to special interests, often explicitly rejecting the public interest principles of the Constitution.

The League works to abolish the new monopolies by publishing articles, talking with public officials, boycotting egregious offenders, and in the future may intervene in court cases. On May 24, 1989, the League picketed Lotus headquarters on account of their lawsuits, and then again on August 2, 1990. These marches stimulated widespread media coverage for the issue. We welcome suggestions for other activities, as well as help in carrying them out.

For more information, send email to league@prep.ai.mit.edu or physical mail to:

    League for Programming Freedom
    1 Kendall Square #143
    P.O.Box 9171
    Cambridge, Massachusetts 02139

Other Gloves

Maybe you've got enough of a budget that you don't want to bother with hacking PowerGloves. The following are other glove options that I'm aware of and information I've received from those companies as of this writing.

CyberGlove (TM)

The CyberGlove features include:

Virtual Technologies 2175 Park Blvd Palo Alto, CA 94306 USA 415.321.4900

Exos

Exos produces an exo-skeleton glove. [ANYONE HAVE CONTACT INFO? -ERIC]

VPL DataGlove

Yeah, like you can afford one.

1