Sharp incorporates desktop power in a truly portable package. Dominic Powlesland digs into the PC5000

The Japanese electronics giant, Sharp has a reputation for producing equipment that is both innovative and reliable.

It should not therefore be surprising that Sharp's latest portable marks a breakthrough in this, the most competitive part of the rapidly changing computer market. The fast development of portable computers over the last two years reflects the need for instant access to the computing power available in any place at any time.

The term portable has frequently been abused by the computer industry, whose advertising agencies seem to have little idea of what the word means. Many of the machines claiming to be portable are transportable rather than easy to carry as the word implies. The arrival of the PC5000 indicates that Sharp actually understands both the meaning of portable and computer.

The Sharp PC5000 is small and light enough to be easily carried around and it also has facilities which place it in a league that draws comparison not with the many portables currently available but with the most recent desktop business micros. The PC5000 is aimed at anyone who requires the high power of a desktop machine but cannot bear to leave it in the office.

Out of its box, one is forced to admire the PC5000's neat design. At first sight, folded up, it looks more like a smart record deck than a computer. Like the Gavilan, its expensive competitor, the lid incorporating the screen is hinged and folds down over the keyboard. There is also an AC adaptor, and a rather fat ring-bound A5 manual. A printer is available as an extra which fits cunningly inside the standard casing.

Measuring 12 x 12.5 x 3.5 inches, the PC5000 weights just over 12lbs including the printer, and has an 80 character x 8 line LCD display screen, and 128K non-volatile Bubble memory cartridge. The whole package, though not fitted with a handle, can be easily slotted into a small attache case.

At the heart of the system, a CMOS 8 bit CPU and an Intel 8088 16 bit CPU provide a processing environment that is directly compatible with the IBM PC and the large number of IBM workalikes. 192K of CMOS ROM is divided up into 64K for the Operating System and 128K for the DOS and Basic, 128K or RAM is provided as standard which is expandable to 192K or 156K if a 64K RAM module is used to replace the Basic ROM module. Access to the ROM/RAM expansion sockets is easily gained by removing two screw-in panels on the base. The same sockets provide a facility for ROM-based software which is currently being prepared by a number of companies.

Internally, control support is provided for the printer, LCD display, keyboard and a small speaker. A real-time clock provides for a number of sleep and alarm facilities. The clock on/off switch is provided on the base and must be set before the machine can be used.

A series of ports on the back of the machine provide for a number of peripherals and the AC adaptor. Connectors for cassette cables link with an audio cassette interface providing a transfer rate of 1,000 bits per second. An external Bus driver provides for the connection of a dual mini-floppy disk unit while other devices are catered for with an RS232 interface socket and a serial interface for a dial direct telephone modem, and definable keypad.

The AC adaptor, weighing another pound, provides a direct power supply from the mains as well as charging facilities for the lead acid battery which will provide up to eight hours of power away from the office. The lead acid battery has a longer life, shorter charging time (only four hours of charging time is required to restore full power) and is lighter and more compact than a NiCad battery of similar power. A simple clip connector links the battery and machine, so replacement is easy. For those working in remote locations spare batteries may be purchased as accessories.

Perhaps the strongest advantage of this machine over others for those on the move is the bubble memory facility. Bubble memory has had little publicity of late, and though developed several years ago has never been widely introduced. Its use in the PC5000 instantly pushes the machine to the forefront of the portables. Bubble memory units have no moving parts, are comparatively sturdy and win hands down against any sort of disk unit for mass storage on the move.

They are also very ast. The PC5000 Bubble unit, with 128K capacity in a 2" square package, functions for the user in exactly the same way as a single disk system. Two Bubbles may be addressed as A and B while external mini-floppy disks, if attached, are addressed as C and D. The Bubble units, which are formatted during manufacture, store data in 512 byte sectors with 8 sectors to a track. They can be write-protected by sticking a reflective label on one side. Sensitive to extreme temperatures, the cartridges have a built-in lock which prevents use at temperatures below 32 and above 104F; like disks they should not be placed near strong magentic fields. Besides the software on ROM chips, packages will be available on Bubble units which, though expensive by comparison with disks, are exceptionally convenient both to use and to carry.

The disk drive (CE-510F) is an accessory which cannot be powered by battery. The dual-sided double-density drives with a capacity of 320K per disk are directly compatible with IBM PC disks, so the PC5000 may well become the basic portable for IBM-based offices. Text or data files created almost anywhere can be held on the Bubble for transfer either by phone or from disk to the master system. The use of MSDOS as the Operating System means a large variety of software will certainly soon be available. Only configuration for the 8 line display is required to run available software on the PC5000.

The 80 character x 8 line display may be operated in 40 character mode for those who find the small character size difficult to use; characters may be shown in reverse, double width and underlined; the cursor may likewise be set to a number of different sizes. The presence of the LCD makes the lid rather heavy, but following the high Sharp design standards it has been fitted with a ratchet to allow a number of screen positions and a damping system stopping the lid crashing if tipped forward.

LCD type displays can be difficult to read, especially when showing small characters. In order to see the display clearly it is important to sit square on to the machine; a thumbwheel on the right hand side of the machine ajusts the angle of the display. After a few days the LCD became much easier to work with. No doubt future versions will be fitted with the new electroluminescent displays currently under development.

The eighth or bottom line of the display may be reserved for labelling the twelve special function keys, an arrangement likely to be frequently used in commerically available software packages.

As well as the standard ASCII character set the PC5000 is equipped with an extensive graphics and foreign language character set. The screen is based upon a 640 x 80 dot matrix, each character being formed from a 5 x 7 pixel block. Individual pixels may be addressed from Basic which also includes instructions for lines, circles/ellipses, and fixed or relative drawing commands. If treated as a partial screen quite sophisticated graphics may be printed by printing several screen dumps in sequence (a feature that may be of some use to the scientist in the field rather than for the businessman); no simple graphics screen dump routine is currently available though I understand this lack is shortly to be rectified.

The importance of a well laid out and comfortable keyboard is one of the most underrated features of micro computer design. Except where mice, touch screens, and other similar devices are concerned, it is through the keyboard that the user operates any machine. The keyboard has to provide facilities for rapid and simple data, text, and program entry, each task having slightly different demands.

In the case of the desktop machine the problem is solved by using oversize keyboards with separate numeric keypads and other special function keys laid out in groups. On many portables and small machines functions are assigned to a small number of keys meaning the user has to be a contortionsist to call up special functions. For the most part the keyboard is arranged in standard typewriter layout.

Besides the standard typewriter keys there are five extra keys on the main keyboard and a row of fifteen special keys above the standard qwerty arrangement. The oversized return key to the right indicates the thought that has clearly gone into the design. A key labelled ALT provides the programmer with single stroke Basic keywords such as PRINT and INPUT, thus making programming both easier and less time-consuming.

Using the CTRL key with the letter P turns the printer on and off. In MSDOS the printer may be used as a typewriter echoing anything displayed on the screen as it is typed in.

In Basic, using the CTRL key with numeric 1 turns the graphics character set on and off, permitting more elegant designs both on the screen and in printout. An ESCape key is provided for running certain applications. The special function keys include on, break and off which provide a break facilities in Basic and an on/off facility to put the machine into sleep mode and thus conserve batteries. Eight special function keys labelled F1-F8, four cursor keys and an INSert make up the remainder.

The special functions are set up as LIST, RUN, SAVE, LOAD, CONT, LPT1:, TRON and TROFF in Basic; all may be user-defined. The cursor keys are arranged in the sequence left, right, up and down; not an arrangement that I am accustomed to but I soon got used to it.

The keys are well shaped for ease of use and are coloured light grey for alphanumerics and orange for the on/off keys, the remainder being grey-brown. This arrangement helps focus the eyes on the alphanumeric keys for fast typing.

The manual has two parts. About a third is devoted to an introduction to the PC5000, its components, and peripherlas and the use of MSDOS. The introductory chapters are clear, concise and well illustrated and clearly written with the first time user in mind.

MSDOS was selected as the operating system of this machine: a major point in the PC5000's favour for those who wish to use off-the-shelf software. Those who have struggled in vain to understand the mysteries of CPM will be delighted with MSDOS since it offers a number of powerful facilities for file handling, communications, and editing while at the same time demanding no attention from the user during applications packages. Never having used MSDOS before I was delighted to find the simple file listing facilities which enabled communications results to be checked.

Each MSDOS command is given a page of explanation. This is adequate for most users who will never need to use such facilities as batch processing, but for someone wishing to understand the ins and outs of the Operating System the manual is of little assistance; fortunately it does not throw the first time user into the same state of utter confusion faced by those using the CPM manual for the first time.

While I am happy with the extent of the information supplied concerning MSDOS, I cannot say the same for the Basic manual: Microsoft appears to have short-changed both Sharp and the user. It seems amazing that Microsoft Basic (G W Basic in this version) should be the most common implementation of Basic for micros. The Basic itself is fast and has some powerful commands, but is not as powerful or as 'friendly' as Sharp's own FDOS Basic available on the MZ3500 business computer, to name one of many.

Microsoft Basic will do the job and it is so widely used that Sharp can hardly be blamed for its choice. What is surprising is that the manual should remain as appalling as ever, merely regurgitated in a different format with the odd change which relates specifically to the PC5000. The manual seems designed to make it as difficult as possible for the first time user to learn to write their own software. The manual, like many others, is written by those who are totally familiar with the language and appears to be a reference manual for others who already know what they are doing. First time users will need to find another book before they can jump into the delicate art of programming.

Surely it would do Microsoft no harm to include some simple programs to demonstrate the different instructions related to sequential and random access files; the explanation of arrays is totally inadequate. Nowhere is a simple program explained which indicates for the first time user how data can be collected, stored, analysed, and retrieved. The error messages frequently fail to do anything other than leave the programmer bemused (does G W stand for Guess What, or Where, the error is?). It may simply be a sign of laxity on the programmer's part to value those Basics which indicate, through cursor positioning, where an error has been detected, but it is incredibly useful. That a manual can have errors in its index does little to raise one's confidence in a company marketing wordprocessing packages. (RENUM and RESUME have swapped places in the index!)

More serious is the fact that the parameter string for communications has been incorrectly stated: it took me over two days to set up communications between the PC5000 and the PC1500 simply because the string as quoted in the manual:

   10 Open "Com1:600,8,N,1,RS,CSO,DSO,CDO,LF,ASC" as £1

has the Bit setting sequence in the wrong order - for MSDOS it should read:

   10 Open "Com1:600,N,8,1,etc.

The discovery of this error was made more difficult since the manual quoted sequence is that which is conventionally used. The error persists on a correction label pasted into the manual.

This should not reflect on the judgement of the PC5000. This problem is universal to all machines and to most computer manuals. For those who have already overcome the idiosyncrasies of the Basic, remembering for instance to enter all spaces as shown since these are not automatically set, the PC5000 will be a delight to program if only by virtue of its total portability.

The 8 line maximum capacity of the screen encourages the user to commit more to paper during program writing than is necessary when using a full size CRT; not a bad thing if one is to write efficient programs. Short programs can be written to print out variable, string sequence, and subroutine position charts for use while programming. Having a full width printer is an absolute boon when programming on the move and to some extent obviates any need for a full screen.

I was able to complete a suite of programs while flying the Atlantic without any difficulty. After four hours of use the batteries showed little sign of power loss although a considerable amount of printing was done. I hope that Sharp will soon produce a CRT interface and provide the facility for switching output configuration from the 8 line to a 24 line screen. Such as arrangement would allow the user to specify which configuration was required each time the program was run and so use the excellent computing power of the machine to its widest advantage.

In a word, it's exceptional. The printer is easy to fit, though the manual was not very clear on this point. I spent several minutes failing to understand it; a vital part of the installation procedure is the connection of one ribbon cable to a connector which includes a clamping sleeve which fits so well that at first I was unable to find it. The sliding clamp must be pulled up before inserting the ribbon cable from the printer; a rectangular plastic plate is provided to push the sleeve back down once the ribbon is in position. Slide the printer into position, secure it with four screws, fit the paper advance handle, replace covers, and you are ready to go.

To say that the printer is a dot matrix type would be correct but may give the wrong impression. A dot matrix is, but by using a 24 dot matrix the characters have more in common with daisywheel characters. Although the print speed is not superfast as up to 37 characters per second, it is perfectly adequate.

More importantly, the printer is silent: it employs a thermal transfer system using either Thermal Transfer paper with a one time ribbon, or may be used without a ribbon or a whisper using Heat Sensitive paper. A small thumbwheel located on the printer chassis can be used to alter the density of the print. Electric eye sensors detect both when out of paper and, if using the ribbon, when that runs out. Paper has to be sheet fed, the printer handling paper sizes up to A4. A pair of hooking points on the back of the grame may indicate that a roll paper holder was incorporated into the design though none is yet available.

The PC5000 is to be supplied with Sorcim SuperWriter and a communications package, SuperComm.

The software is not yet available in the UK and I was unable to persuade Sharp USA to let me have a set for evaluation so I can make little comment on the supplied software. But I was able to try out SuperWriter while visiting the US. The whole package is completely menu-based and is thus fairly easy to use. Certainly I found little difficulty in using it without reference to the manual, a fact which will appeal to the business user who has no desire to lug about hefty extras.

It is difficult after a very short evaluation to say much more than how fast or easy to use any given micro is. After three weeks use I can say that regardless of the specifications (which are outstanding anyway) or any benchmark tests that the PC5000 is a superb computer.

I have used it in the office, on a plane, on a train and for demonstration purposes at an archaeologists' conference. For any task requiring the collection of large bodies of data in remote situations the PC5000 is the perfect machine. It offers powerful communication facilities which allow field data collected using a handheld computer such a the PC1500 to be quickly downloaded, verified, printed out and analysed in the field.

The wordprocessing package allows reports to be generated directly on-site whether they are for scientific or business purposes; this is a valuable luxury made totally viable on account of the operating capacity of the machine with the Bubble. On returning to the office, data and documents can be unloaded either onto the accessory disks or to another host computer for permanent storage.

At present, the situation is such that almost any computer becomes technologically backward almost as soon as it is released, buyers seem concerned that they should not buy the wrong machine because a better one will almost instantly be available. There is absolutely no logic in this argument: if you find a machine that does what you want it to you have found the machine that you need. With both a wordprocessing and a communications package supplied with the machine, a spreadsheet available and other software on the way, the PC5000 will acquire a leading place among portables. There is sure to be a huge demand for the machine - all that remains is to see if Sharp can satisfy it.

Given a large demand, it must be only a matter of time before other peripherals such as a CRT interface are produced to take this small machine into direct competition with more conventional office machines.

Despite my reservations about G W Basic and the machine's graphic limitations the machine is well designed, very powerful, easy-to-use within the limits imposed by the LCD screen and also cheap, costing half the price of the only comparable portable, the Gavilan, and considerably less than an IBM PC. We can expect to see it around for several years to come.

Price: £1,374, £194 per bubble memory
Processor: 8088 plus 8-bit CMOS
ROM: in CMOS 192K
RAM: 128K
Screen: 80 character by 8 line LCD
Keyboard: Standard typewriter plus five extra keys and 15 special function keys
Interfaces: Cassette, RS232, modem output, external disk
Operating System: MSDOS
Software: Sorcim SuperWriter word processing package SuperComm communications package
Distributor: Sharp UK (061) 205 2333