Stroke of genius. (keyboard evaluation) Herbert M. Sandler.

Necessity may not have mothered this invention, but convenience and ease were certainly parties to the conception. Inhome Software has filled a gap with a sturdy, full-stroke keyboard that substitutes for the membrane original on the Atari 400 computer. I installed the keyboard in about 20 minutes using only a screwdriver.

Although this crowning of the 400 does not quite make an 800 (it might be dubbed a 599), at $105 it is a reasonable upgrade.

When I considered a small computer for our family's recreational and entry-level use, I narrowed the choice to three machines: the Vic 20, TI 99/4A and Atari 400. The first two have full-stroke keyboards, with a feel similar to that of a typewriter, while the Atari has flat, printed board (Atari calls it a monopanel). Caveats About The Keyboard

The 400 was appealing in its superior graphics, sound and game adaptability and its 40-column display. Its big brother, the 800, had a "normal" keyboard and a second cartridge compartment but at double the price, and with nearly the same interior and output, it seemed less of a value. A several hundred dollars savings buys a great deal of software. So, disregarding caveats about the plastic membrane keyboard, I brought home an Atari 400. I have been very content with the choice--except that the keyboard was truly a pain to use.

The printed mylar panel is peanut-butter and Dr. Pepper-proof. It does almost everything that the 800 does and yet...

I found myself poised above the flat quasi-keyboard with, switches on, in the full flush of creativity knowing that I cannot pounce upon the keys. Instead, I had to descend purposefully, adjusting to a kind of squeeze--a massage that at times elicits a reluctant response.

My wife, an expert on a heavyweight office typewriter, nearly mutinied after being introduced to the printed laminate of the 400. It is not friendly to the touch typist because the fingers cannot distinguish the home keys. And the lack of a sense of detent restrains rapid typing.

When programming the computer, "entering" the commands suits the action better than "punching them in." However, we did not intend to displace the office Selectric, and we have been satisfied with the computing ability of the 400 aftermarket.

Along comes an aftermarket improvement to raise an itch of dissatisfaction. Merely replace the membrane keyboard of the Atari 400 with Inhome Software's B Key 400 kit and your problems are solved, the manufacturer claims.

I was a bit skeptical, but I brought home the new keyboard with anticipation. The keyboard package consists of a printed circuit board with 61 individual spring switches connected to a flat cable and a packet of attractive, contoured keycaps. The four-page instruction manual, though adequate, needs larger and clearer illustrations; everything seems to have been crowded toward the tops of the pages. Installing The Keyboard

The operation started smoothly. You remove the top of the computer, which is held on by four Phillips-head screws. Then you trespass into the interior (which will void the warranty) and disconnect the ribbon cable from the computer to the membrane keyboard. You maneuver the keyboard out of the top cover and put it away for the relic collection.

Next, you plug in the new keyboard using its own ribbon cable. And, as fore-warned in the manual, you need a third and fourth hand to steady the machine while you hold aside wiring and wiggling home the cable assembly. A strong flashlight or lamp makes the work a bit easier. The new cable pins (really wire ends) are not as substantial or manageable as the flat, stiff prongs of the original. After some anxious moments, however, a firm, persistent grip accomplishes the coupling.

You fit the new keyboard, with the 61 switches exposed, into place over the cable assembly, and reattach the top of the computer. I was eager to confirm the correct isntallation; I switched the unit on and pressed a few unmarked keys. They worked, and I haven't squeezed a laminated keyboard since.

The last step calls for installation of the keycaps. By moving five of the keys (CTRL, CLR/SET TAB, CAPS/LOWER, ESC and DEL/BACKS) to either side of the spacebar as on a professional keyboard, the designers have been able to spread out the alphanumerics a needed couple of inches. The keycaps are full-sized, contoured, and quite receptive to touch typing. The materials seem durable enough to support the manufacturer's claim of a life of one million operations.

I have a few minor gripes. The keys, and especially the spacebar, rattle a bit (though no worse than the keyboard of the Atari 800 and many others). The shift keys are the same size as all the others and are placed inconspicuously. The return key, too, is now smaller, but at least it protrudes a bit at the end of its row.

It would be nice to have some of the keys color-coded. The control key could be color-coordinated with other keys related to it. I may try to color-mark the RETURN and SHIFT keys with a small stick-on dot label and dampen the space bar clatter with a bit of felt. Keyboard Enhancement Kits

The Atari 400, of course, isn't the only model with a plastic membrane top. Users of the extremely popular Timex/Sinclair 1000 computers have to contend with an even smaller panle keyboard. Perhaps a dozen "keyboard enhancement" kits are now available to them, ranging from a plastic overlay with finger-guiding holes to full-strike conversions in cabinets large enough to house both computer and add-on RAM circuits. This wide array of aftermarket equipment has been fostered by suppliers from Britain, home of the Sinclair computer.

Inhome Software is not the only manufacturer offering an upgrade for the Atari 400 keyboard. RCE of Grant's Pass, OR, has also entered the market with a pair of keyboard and calculator options under the Commander label. These are separate wood-trimmed enclosures with eight feet of connecting cable. They can be used without disturbing the original keyboard of the Atari 400. The numeric keypad model permits calculator operations without involving the computer keyboard. Installation is a bit more involved for the two models, and with their deluxe features, they are priced higher than the Inhome conversion.

Meanwhile, back at the Sunnyvale, California ranch, there are rumors that Atari has seen the light and plans to introduce an intermediate model, between the 400 and the 800, with an upgraded full-stroke keyboard.

That doesn't ease the way for present users of the 400, however, which brings us to the next question.

Is the B Key 400 keyboard worth the price and the effort to install it? i would say yes: for the touch typist typing becomes more pleasant and accurate. My wife says the new keyboard has a softer and more effortless touch than her IBM office typewriter. The keyboard may not be a dead-ringer for the 800 (or as elegant as other microocomputers), but ergonomically speaking, it has the right stuff.

The solid-looking console is handsome enough with its chocolate-brown molded keycaps. The B Key 400 does well. In fact, it is inviting the family back to the keyboard, where they are in touch once again.

Does anyone have a use for a dead membrane-type keyboard?

Products: Inhome B Key 400 (computer apparatus)