Texas Instruments 99/4A Computers

described by Charles Good
Lima Ohio User Group
Converted to HTML by Rob Patton

This device was (and maybe still is) literally years ahead of the competition when first introduced to the public at the January 1983 Consumer Electronics Show. When attached to the TI99/4A it allows speech recognition with specific Milton Bradley game and educational modules. The user speaks instructions into a microphone, and the 99/4A understands the spoken words and responds accordingly. With the MBX system, our old fashioned 99/4A's can do tricks that even the most sophisticated modern home game machines can't do. Voice recognition is NOT available even today for Nintendo and Sega game systems. These days you can find voice recognition hardware costing hundreds of dollars advertised in Computer Shopper for use with MSDOS and MAC computers. In T.I.'s last complete price list of 99/4A products published in June 1983, the MBX system lists for $129.95. It's too bad only only about 300 were ever made!

Although the title of this article might suggest that the MBX system was made by T.I., this is not so. The MBX was manufactured and sold by the Milton Bradley Company. T.I., under license from Milton Bradley, manufactured and sold the specific software modules designed for use with the MBX. The MBX system comes packaged in a box with the the same kind of "photograph of the product on a black background with white letters" style found on 99/4A console boxes. The actual MBX hardware is in the same gray plastic used for the most recent 99/4A consoles and official T.I. cassette program recorders. As a registered 99/A owner, I received by mail in early November 1983 from T.I. (not from Milton Bradley) an advertisement describing the MBX and MBX specific software. Apparently Milton Bradley intended to have the MBX on store shelves for the 1983 Christmas season, but canceled all further production after BLACK FRIDAY. There is no serial number on my recently purchased used MBX, but it bears a sticker that says "MBX Control number 8310". This may mean that my unit was manufactured in the 10th week of 1983. My guess of 300 MBX units actually produced is based on the very limited availability of this product for sale at TI shows I have attended and in the possession of T.I. owners known to me, as well as the fact that UNISOURCE once advertised that they had 200 MBX's for sale.

There are three parts to the MBX "system", the control box, the joystick, and the headset/microphone. The heart of the system is of course the control box. It measures 10 x 7.5 x 2.5 inches and includes its own built in speech synthesizer. This box plugs into the joystick AND the cassette recorder ports of the 99/4A console. The MBX system is designed to be used with just the console and specific software cartridges. There is no provision in any of the MBX software modules for disk usage. Since one of the MBX connections occupies the cassette jack, you can't use a cassette recorder either. You must disconnect the regular speech synthesizer to use MBX. To hear speech, the two speech synthesizers cannot coexist.

The control box has a side port for the required AC power source. On the front of the control box are two 9 pin male D ports for joysticks, a jack for the headset/microphone, and an on/off switch. When you slide this switch to the ON position the MBX control box responds by saying "ready" in a well modulated female voice. This voice, and all speech generated by the MBX system, comes from a speaker at the top back of the control box, not from the monitor speaker. Music and other non-speech sounds continue to be heard from the monitor's speaker. Only spoken words (synthesized speech) are heard from the MBX system's speaker. You have to turn on the MBX before you turn on the console in order for the 99/4A to recognize the presence of the MBX. When activated, the MBX system disables the FCTN/0 QUIT console keypress. On the top of the control box is a 64 position membrane keypad. The top row of 8 keys on this keypad functions in the same way with all the MBX software modules that utilize this keypad. These top row keys include RESET, VOLUME UP (the volume of the speech coming from the MBX's built in speaker, not the music and sounds coming from the monitor speaker), VOLUME DOWN, MIC (toggles on and off the ability of the microphone headset to "hear" spoken words), YES, NO, PAUSE (stops game action), and GO. The action of other 56 positions on the control box keypad is specific to the particular software module in use. A very decorative keypad overlay comes with those software modules designed to utilize the rest of the MBX control box keypad. These overlays slip easily and snugly over the top of the keypad.

The headset superficially resembles a set of "walkman" earphones, but in fact contains no earphone speakers. The things that cover your ears are just pads. The microphone is positioned in front of your mouth and its position is adjustable. Physically the headset unit is flimsy. The wire leading to the microphone is thin and subject to stretching and damage at the point where it enters the adjustable microphone arm of the headset as the microphone arm is adjusted back and forth. Fortunately a handheld microphone designed to plug into a cassette recorder will also work with the MBX if the headset microphone breaks. The advantage of the headset over a handheld microphone is that the headset allows easy two handed manipulation of the special MBX joystick.

One joystick comes as standard equipment with each MBX system. A second joystick is listed in T.I.'s last 99/4A price list for $29.95 and can be plugged into the second joystick port on the control box. This would give each of two players their own separate joystick. In actual use of the MBX software modules a second joystick isn't really needed. Only one player at a time uses the joystick. The two joystick ports on the control box respond the same. There is no "joystick #1" and "joystick #2" as there is with the 99/4A console. The MBX joysticks are very fancy and cannot be used by themselves directly from the 99/4A's joystick port. Likewise, you can't use regular joysticks from the MBX console. Movement of the MBX joystick handle is very smooth. The device is described in promotional literature as a "triple-axis analog control that allows 360 degree object rotation and left to right and front to back proportional control of all movements." The word ANALOG suggests infinitely variable control. The MBX joystick's arm appears to produce the same kind of 8 direction movement typical of joysticks. The "analog" infinitely variable control is the rotating knob on the end of this joystick arm. With some MBX games this knob will rotate the object under control to face any direction, for example to orient a gun prior to shooting. In the MBX baseball game this knob controls the force of a batter's swing. Minimum swing power results in a bunt. A trigger style fire button is included with the MBX joystick, as well as three other buttons. These three buttons resemble mouse buttons and have specific purposes when using specific MBX software modules.

How does MBX allow the 99/4A to respond to voice commands? At the beginning of each session with an MBX software cartridge that allows voice recognition as an option, the user is asked if he wants to use voice recognition. This is always optional. All the MBX cartridges can be used WITHOUT voice recognition by using the keyboard and/or the MBX keypad for input instead. If voice recognition is chosen, the user is asked which commands are to be given in voice. It is possible to use voice for some commands and the console keyboard or MBX keypad for other commands, or to have all non joystick input by voice. The computer then directs the user to speak the possible commands (big, small, left, right, pencil, pen, centerfield, shortstop, etc) into the MBX microphone. This "voice training" of the MBX to recognize the user's voice patterns is repeated twice. Voice patterns are stored digitally on chips inside the MBX for the duration of the session, until the MBX is reset or shut off. This voice pattern storage is probably similar to that of some modern telephone answering machines. My home answering machine does not store the greeting message on cassette tape. Instead, my "This is the Good household answering machine..." message that greets incoming calls is stored on a chip and played to callers every time I don't answer the phone quickly enough. As with the MBX, I can quickly erase my "stored on a chip greeting" and replace it with another on my answering machine. An MBX user can use any word desired for a particular command, as long as the user is consistent in using this word. For example, in CHAMPIONSHIP BASEBALL a user can speak the imaginary name of a fielder when asking for a particular fielding position. During voice training the computer can ask the user to speak the word "shortstop" and the user can reply "Tony". As long as the user remembers that Tony is playing shortstop, the game will work OK.

After voice training the game begins and the computer responds to sounds it hears via the MBX microphone. Users have to be careful to ONLY speak when they want the computer to perform some action. Casual conversation by the user can result in unexpected things happening as the computer interprets some of this conversation as specific spoken commands. The solution to this problem is to turn off the MIC using the MBX keypad when response to voice commands is temporarily not desired. A small symbol continuously on screen indicates the ON/OFF status of the microphone.

How well does it work? How reliable is MBX's voice recognition? It is about 80-90% reliable. Sometimes the MBX either totally ignores a verbal command, or the command is incorrectly interpreted as a different verbal command. Part of the problem is that during the excitement of game play, a player's voice may sound different than it did during voice training. In CHAMPIONSHIP BASEBALL it can be very annoying to command a throw to "second" and instead see the ball thrown to "centerfield". All voice commands can instead be activated from the 99/4A keyboard of the MBX's keypad with almost 100% reliability. All the modules designed for use with the MBX, even those that absolutely REQUIRE the MBX, can be used totally without voice recognition. For really serious accurate game play, one should bypass the MBX's voice recognition feature. My testing panel is divided in their preference for voice recognition. Meaghan, my 5 year old daughter, likes to use voice recognition. I think she finds voice easier then reading the MBX overlay or memorizing complex 99/4A keypress sequences. Ian and Colin, ages 12 and 9, both prefer not to use voice recognition. High scores are important to these two serious game players, and such scores are easier to obtain with accurate game control.

What software is available? The following cartridges by Milton Bradley were specifically designed for use with the MBX expansion system. All these include speech synthesis and many also allow voice recognition. The speech synthesis of these software modules (but not speech recognition) can be accessed using the regular TI speech synthesizer without using the MBX system. They were officially released by T.I. in 1983 and 1984. The last (June 1983) 99/4A catalog published by TI lists these modules for $50 and $60. I have seen some of the "MBX system required" modules listed by TRITON in the past for as little as $3. Currently they are all available from L.L. Conner Enterprise for $15.
Quoting from the booklet TEXAS INSTRUMENTS HOME COMPUTER PROGRAM LIBRARy that came packaged with many TI modules sold in late 1983: "The BRIGHT BEGINNING SERIES includes four games which teach elementary programming, music, and other learning concepts. Ages 4-8."

I'M HIDING (MBX system is required).

"The ARCADE PLUS SERIES has six arcade style games that take you from home town ball parks to meteor belts far, far away."


I have been told that Barry Boone has written some software that will allow programming the MBX and its non standard joystick. Such software would turn the MBX into something much more significant than a game enhancement. So far, this software has not been made available to others.

NAME Must have MBX Uses KeypadUses rotation knobbuttons 1,2Speech Reconition
I'M HIDING Yes Yes No No Yes
BIGFOOT No No No Limited No
SUPERFLY No No Yes Yes Yes

Most software cartridges allow use of the MBX joystick as an option.
METEOR BELT requires two MBX joysticks if the MBX system is used in a two player game.
All software cartridges allow limited use of the MBX keypad for RESET, PAUSE, and GO.

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