Z88: A Real Portable Computer

Clive Sinclair's Z88 was a genuine breakthrough -- the first portable computer I could confidently carry around in my briefcase without having to worry about the state of my batteries. It also let me sit out in the garden writing in strong sunlight, something I can't do on my ThinkPad today. Thanks, Clive.


[The Cambridge Computer Z88][wc?][27 Aug 88][chb]

In our issue of March this year we ran an exclusive hands-on preview of a new portable destined to arrive on the market the following month at a price ofjust under 200 pounds. The machine came from the stable of Clive Sinclair, and perhaps because of this its announcement was welcomed with affection by some, but also greeted with a good deal of cynicism by those who remembered the unfortunate launch history of the much delayed QL. It would be late, they predicted, and it would be technically disappointing.

The cynics were half right. There has been a dribble of machines out of the Cambridge Computer mail order depot, but in practice the product only became widely available during the early days of September -- five months behind schedule. And as an added sting it is now priced at 250 pounds -- a 25 percent increase.

But the cynics were also half wrong. Our brief hands-on encounter with the machine five months ago and extensive talks with the backroom team suggested that if the finished product met only 50 percent of its design goals it would still be a useful tool for most people who need a computer -- portable or not. The Z88 has met its design goals, and in our opinion deserves to be a realwinner.

To recap briefly on our March preview, the main intentions of the designers were:

An affordable, highly portable light-weight A4-sized computer that fits in a briefcase -- along with all the other stuff you would normally carry.

A full-sized keyboard that would be not unduly disconcert a professional typist, but which would be unobtrusive if used for note-taking in, say, seminars and board-meetings.

Bundled software that takes care of word-processing and spreadsheeting needs, includes a universal programmable language, as well as diary, calendar, calculator and file transfer facilities. DOS compatibility is not required, but data must be easily transferrable to and from industry standard desktopcomputers.

Memory expansibility without clumsy external add-ons or any change in the size.

To dispense with battery-consuming disk or tape drives, but offer an easy to use solid-state filing and archiving system that works as a reasonable substitute.

Similarly to dispense with a power-hungry CRT or back-lit display, but provide a screen that is easily legible in ordinary light.

To run all this through a sophisticated context-switching operating system that allows you to move easily between activities, suspending them and returning to them exactly as you left them.

With any machine as novel as the Z88 the reviewer has the problem of making a thorough assessment that is not based on the prejudice of experience with very different systems. We settled on a "soak test" and determined to carry the machine everywhere for six weeks and transfer as much work to it as seemed feasible.

At first blush there were shortcomings we feared might be difficult to live with. The screen and the characters it displays are small, although remarkably legible, and the almost silent rubber keyboard is unnerving after the clack-clack of the traditional desktop equivalent. Being used to large hard disk desktops with multi-megabytes of storage we were not sure how we would take to the old beginning-of-the-decade limitations of 32K of RAM.

To make matters worse, our early, pre-production version of the machine exhibited an unendearing tendency to lock up mysteriously at odd intervals. Happily this was completely cured when the 128K internal ROM that holds the operating system and the application programs was replaced by version 2.2, used in the production model.

What won us over -- quite quickly, in fact -- was the sheer portability of the hardware combined with the remarkable level of sophistication of the software. Weighing less than 2 pounds, we found that the Z88 really is a machine that you take with you "in case" rather than "because".

The Z88 is only physically "a lightweight", and surprising levels of sophistication can be uncovered below the relatively simple user interface for those inclined to explore. For example, the software includes a very respectable and fast implementation of BBC Basic -- which many wordprocessing and spreadsheeting users may never need to disturb from its slumbers in the ROM. But those who do will discover sooner or later (it is barely mentioned in the manual) that embedded in the Basic is an assembly language that allows programmers into the very lowest level of the machine. In effect the Z88 comes with a built-in, fully-fledged program development system!

You do not need to tunnel to these depths to discover the subtlety of the software. Initially you will probably be interested in using the machine to write a one document at a time, or work on a spreadsheet.

Both applications are taken care of by the combined wordprocessor and spreadsheet, Pipedream. Pipedream is complemented by a combined Diary and Calendar program, a clock, a calculator, a file manager, a terminal emulatorand an export/import facility for swapping files with an IBM PC or similar desktop machine. Pipedream and the diary have to be loaded like ordinary programs (although they will remain loaded when you switch off). The other utilities, known as "pop-downs" can be pulled into view and dismissed again rather like the Desk Accessories of the Macintosh.

One key feature of OZ, the Z88 operating system, is the ability to load a selection of applications into memory at the same time and switch quickly between them. You can also load Pipedream as many times as memory will allow, so that you can switch, say, between a letter, a report, a spreadsheet and a set of rough notes. All of these run under the same single copy of Pipedream in the ROM, which insures that the program itself makes no (or strictly speaking very little) additional demands on memory, and as much RAM space as possible remains for data.

Some minimal task switching is possible on the unenhanced machine, but to explore the full possibilities you really need to increase the memory. Three empty slots are provided under the keyboard for you to plug in what Cambridge Computer calls "cards". These are square black chip containers about the size of a book of matches, and are available at present with either 32K or128K capacity. The latter are more expensive, of course, but are the ones to go for if you can, as they actually drain the battery less than the smaller capacity cards.

The way in which Pipedream combines the duties of spreadsheet and wordprocessor is not difficult to grasp in simple terms. Most modern spreadsheets allow text entered into a cell to extend across into the screenspace that would otherwise be occupied by adjacent cells to the right, provided those cells are not being used.

Pipedream behaves similarly, but a Pipedream cell, known as a slot, has in addition to its physical width on the screen, a property known as the wrapwidth. When text entered from the keyboard reaches the wrap width it will break at the nearest convenient space and begin spilling into the next slot below in the current column. So the software appears to behave like an ordinary word processor, but the underlying slot structure remains, with some useful, and some less felicitous side effects.

Slots let Pipedream handle multi-column text, a surprising talent in such a small machine. You can do this easily by, for example, setting the screen width of column A to 30 and the wrap width to 25. At any time hitting the tab key will take you across to column B. Now the text you enter will wrap that the wrap width set for that column and return to the left hand margin of column B each time it does so. This produces side by side columns of the kind used in laying out lists and tables.

Text can also be emboldened or underlined (or both at once) with results that show on the screen -- again, quite an achievement for a machine of this size. Italics are depicted as small letters, and other enhancements like sub- and super-scripting can be indicated, although they remain on the screen as leading and trailing codes.

The main problem posed by the underlying slot structure of Pipedream is the inability to mark, move copy or delete blocks of text in any other way than by whole slots at a time. Pipedream will respond happily if you want to delete, say, lines 24 through 33 because each line occupies a slot. But if, as is more likely, you want to operate on words or sentences, which in the untidy nature of text will begin and end in the middle of the physical lines on the screen, the block marker mechanism can't cope.

There is a way round this, but it introduces an additional step. A command is provided to split the text at the cursor and flow it into the slot immediately below. Once this is done the line break corresponds to the text break you want to make. Perform a similar operation to set the end marker ofthe block and you are ready to carry out the block manoevre. Once this has been done you will probably need to reformat the text to flow evenly to the right margin, but this can be accomplished with a couple of keystokes.

With a 32K or 128K card in slot 1 you can easily load several documents into memory at the same time, and switch between them using the Index key on the bottom left hand corner of the keyboard. Although all the data you create or load into the system lives in RAM, the memory is allocated between file space (which behaves like a disk drive) and the "activity area", which corresponds roughly with the transient program area (TPA) of a DOS-based system -- with the important difference that application programs never have to be loaded into it as they run in the ROM.

This distinction between two types of memory is not essential in a machine of this kind, and adds somewhat to the complexity, although it has advantages when it comes to conveying data in and out of the system. It also allows for a very flexible way of organising information, in nesting sub-directories like those used in MSDOS.

As with the Microsoft operating system, files are automatically marked with the time and date of their creation and last revision. By using the Filer utility they can be listed, copied between devices, renamed, deleted and even transferred onto a permanent storage device called an EPROM (erasable programmable read only memory) which can optionally be installed in the third card slot. The EPROM is erased for reuse by bathing it in ultraviolet light, and a device to do this is available as an extra.

One shortcoming of the filing system is the inability to copy a number of files distinguished by an ambiguious filename. DOS allows constructs like"COPY *.DAT C:". Oz understands ambiguous filenames, but a copy command along those lines would result in all the files being appended in one large file.

The import/export utility works well in conjuction with additional software supplied for the IBM PC and clones, and we had no difficulty in translating material generated by WordStar into and out of PipeDream format and transferring files between the two machines. Features like underlining and emboldening are carried over automatically.

If WordStar is not your favorite word processor, it is very easy to transfer files as pure text. For this purpose you can substitute any standard comms package for the DOS utilities provided by Cambridge Computer.

Translating PipeDream in and out of Lotus format is a trickier proposition because the Z88 application does not pretend to duplicate all the 1-2-3 features, and has several special features of its own. Ordinary spreadsheets involving simple arithmetic, dates, most trig functions and the CHOOSE and INDEX functions are converted, but named ranges and macros are not carried over.

The diary is eminently useable, although very simple in concept. An unlimited area of text space is provided for each day, but what you don't use doesn't take up memory. The day of the week, month day, month and year appear in a box on the right hand side of the screen, leaving you with an 80 col by 8 line scrolling text area that behaves very like Pipedream, but without the multicolumn facility or the ability to create enhanced text. As withPipeDream blocks of text can be marked and moved, copied, deleted or written to disk. You can use the cursor keys to move from day to day, and choose whether you take notice of or ignore empty days.

At any stage you can pop up the calendar, to move to another day of another month, and then return to the diary to find yourself in the newly selected day.

Simple free-form text searching allows you to go quickly to particular days, so that if you are meeting Sir Clive Sinclair some time next month but you can't remember when, entering "Sinclair" in response to the "String to search for" screen will take you directly to the day.

Diary entries can be cut and pasted like ordinary text, streamlining the recurrent problem of rearranging appointments -- something not always easy todo with electronic diaries.

The calculator is unfortunately limited to elementary arithmetic, and unit conversion between English and metric systems, although if you want trigfunctions, Pipedream and Basic provide them. Surprisingly the design doesn't allow you to transfer the results of calculations into PipeDream.

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The most valuable feature of the whole machine is its sheer portability. It is designed for the briefcase, and we found it small and light enough that it can be carried everywhere without having to make a decision whether to take it with you or not.

The small screen is highly legible and scrolls fast enough to take you around a large document quickly.

We don't see the Z88 as a competitor against DOS portables like the Toshiba 1000 -- if DOS compatibility is really what you need. But it might be worth considering whether you can get by without it -- and gain real portablity in the process.

The Oz operating system offers rich possibilities to independent software developers. If sales of the machine through outlets like Dixons and Comet go as expected, the handful of third party software manufacturers already developing application may well become a bandwaggon. But initial sales will depend on what the machine has to offer on its own, and in our opinion that is a great deal.

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