TI-99/4A-81年- 科技百科 -互联网博物馆，你我的知识加油站

　　Texas Instruments袭击家庭电脑市场所持续的时间非常短，而TI-99/4的失败则很好地说明了这个问题。在1979年，当其他的家庭电脑都和电视机连接在一起时，TI-99/4还只能和它的显示器一起运作，而事实上它的显示器是一个体积大小为13英寸的Zenith TV。它的键盘是由Chiclet大小的按键组成，用户还只能用它输入大写字母。

　　两年之后，该公司宣布发行了TI-99/4A，该电脑带有性能更强的处理器、更好的键盘、可和用户的监视器相连接、包括有大写字母和小写字母、售价比TI-99/4还要便宜，当时TI-99/4的售价达到了1150美元。

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The TI-99/4A is a redesign of the TI-99/4 system, which was discontinued. The new "4A" has a new graphics chip and a better keyboard.

About the only way to expand the original TI-99/4A was from the expansion port on the right side of the console. Memory expansion, a serial interface, a floppy drive and other peripherals can be plugged in here for added capabilities.

Unfortunately, this string of peripherals could easily reach many feet in length, as this picture indicates!

To remedy this situation, TI released the Peripheral Expansion Box as a more convenient way to expand the TI-99/4A. It is huge, and of very solid and high quality construction.

Introduced in January 1982, the Peripheral Expansion Box cost $1475.00, including:

Disk controller card and one SS/SD floppy drive
RS-232 interface card
32K memory expansion card

It is estimated that one PEB was sold (250,000) for every ten TI-99/4A consoles sold (2.5 million).

There is space inside the "PEB" for 8 cards, although one slot is required to contain the interface card which leads into the console via a very large flat cable.

The open PEB shown here has the interface card, an RS-232 Serial card, 32K RAM memory expansion, and floppy controller cards installed.

If the PEB is too large for you, CorComp, who manufactured many of their own expansion cards and peripherals for the TI-99/4A line of computers, released the CC-9900 Micro-Expansion System for the TI in May of 1984. It is a conveniently small expansion unit that plugs into the expansion bus on the right side of the 99/4A, and contains the same features as the PEB default configuration, and then some:

Parallel port

Serial interface

32K RAM expansion

Floppy disk drive interface Unfortunately, CorComp filed for bankruptcy just a few months later, in August of 1984.

By August 1982, TI is losing shelf-space to competitors, and issues a $100 rebate on the TI-99/4A.
At the end of 1982 the TI-99/4A is the number one home computer in America, with approximately 35% of the market share, and producing 150,000 consoles a month.
In February 1983, in order to remain competative, TI again cut the price to dealers, and the cost of a TI-99/4A dropped to about $150.
In June 1983, TI released the cheaper beige plastic version of the TI-99/4A, and again had to cut the price, to less than $100. They are now selling computers for less than it costs to manufacture them! As a result, TI experienced a second-quarter loss of $100 million.

The new beige TI-99/4A has a re-designed and cheaper to build motherboard, as well as a cheaper, all plastic case. After the beige TI-99/4A was released, all new cartridges were also beige.
So far, we have over 80 unique cartidges in the collection. Always looking for more!

At about the same time, Milton Bradley announced the futuristic Milton Bradley Expansion System (MBX) for the TI-99/4A. It not only offered speech synthesis, but speech recognition, when used with specific Milton Bradley cartridges.

After an initial voice training, the MBX system will recognize specific commands spoken into the microphone, as well as keyboard and joystick input.

The joystick of the MBX is a 360 degree joystick - in addition to the usual up-down-left-right motion, it also rotates like the volume knob of your stereo.

Unfortunately, in March 1984, shortly after the MBX became available, Texas Instruments decided that it could not compete in the home computer market, and discontinued the TI-99/4A. Thus, very few MBX systems were actually sold, and only about ten MBX specific game cartidges were ever produced.

Back in January 1983, TI announced the TI-99/2 computer, to be sold for only $100.00. It had little in common with the 99/4A, the 99/2 was to be an inexpensive beginners computer like the Timex Sinclair 1000.

Five months later, in June, they dropped plans to mass produce it, and it was never released. Strangely enough, there were advertisements and even articles published in computer magazines of the day.

NAME	TI 99 / 4A
MANUFACTURER	Texas Instruments
TYPE	Home Computer
ORIGIN	U.S.A.
YEAR	1981
END OF PRODUCTION	1984
BUILT IN LANGUAGE	TI Basic
KEYBOARD	QWERTY full-stroke keyboard, 48 keys 2 x SHIFT, CTRL, ALPHA LOCK, FCTN
CPU	TI TMS 9900 (with 256 bytes 'cache', actually it accesses to 256 bytes of RAM)
SPEED	3,3 MHz
CO-PROCESSOR	TMS 9918 (TMS 9929 in Europe) - Video / Sprite
RAM	16 KB - Memory expansion card can be added : 4 KB or 32 KB (up to 52 KB)
VRAM	16 KB
ROM	26 KB?: 8 KB ROM connected to the CPU + 18 KB ROM in byte-serial bit-mapped circuits (usually known as GROM, Graphic Only Memory)
TEXT MODES	32 x 24 (16 colors), 40 x 24 (2 colors)
GRAPHIC MODES	Multicolor mode : 48 x 64 with 16 colors 256 x 192 with 16 colors (only accesed via machine code) Sprites (only with TI-Extended Basic)
COLORS	16
SOUND	3 channels, 5 octaves (110hz to 55khz) and 1 noise channel (periodic and white)
SIZE / WEIGHT	38 x 25,5 x 6 cm / 2,15 kg
I/O PORTS	Tape interface, RGB video, Joystick (2), cartridge slot (Solid State Cartridge)
OS	TI's own system, but a p-code card could be added, which gave access to the UCSD p-system and a Pascal compiler.
POWER SUPPLY	Special TI external PSU (pins 1,2 : 16v / 1,6A -- pins 2,4 : 8v / 0,15A)
PRICE	?9 (UK, 1983)

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