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Hewlett-Packard HP-100LX

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*512kB model also available

Second in HP's line of MS-DOS compatible pocket computers, the HP-100LX offered numerous improvements over HP-95LX. Most significant among these is the display: the HP-100LX was the first pocket computer with a screen capable of showing 25 lines, each a full 80 characters in width. The display was, in fact, software-compatible with IBM's CGA (Color Graphics Adapter) specifications, which made the HP-100LX instantly compatible with a large number of third party MS-DOS applications.

Looking at this machine, I almost feel sad that the MS-DOS era is over. The HP-100LX is a superbly practical device, capable of performing most of the tasks we routinely use our computers for: text processing, spreadsheet calculations, notetaking or storing addresses. Although it was not designed for Internet use, third party applications (most notably, WWW/LX) make the HP-100LX a fully functional Internet device: it can be used for Web browsing, e-mail, and more. Yes, it does make you wonder why we need nearly a thousand times the memory, disk storage, or raw processor speed to accomplish the same tasks on our modern desktop computers.

Not forgetting its business customers, Hewlett-Packard included a financial calculator "applet" with the HP-100LX. Very similar to HP's "formula programmable" business calculators, it offers a comprehensive set of built-in functions and a powerful formula programming capability. An implementation of my favorite programming example, the Gamma function, neatly demonstrates this capability:

Gamma=(-1)^SIGMA(i,X,0,1,1)/EXP(SIGMA(
i,X,15,1,LN(ABS(i))))*L(q,SIGMA(i,X,15
,1,1)+X)^q/EXP(q)*SQRT(2*PI/q)*EXP((((
(1/1188/SQ(q)-1/1680)/SQ(q)+1/1260)/SQ
(q)-1/360)/SQ(q)+1/12)/q)

However, if you prefer to program this device in its "native" mode, Microsoft's DEBUG.COM is included along with other MS-DOS utilities; all you need is a set of machine language reference manuals and you can start writing your very own DOS programs in no time!