Classic Computer Magazine Archive CREATIVE COMPUTING VOL. 10, NO. 1 / JANUARY 1984 / PAGE 55

The Sharp PC-5000; a desktop computer in a portable package. (evaluation) David H. Ahl.

The Sharp PC-5000

A Desktop Computer in a Portable Package

Sharp, The Company

Sharp is a giant of a company with sales of $3.8 billion in sales worldwide and nearly $800 million in the U.S. U.S. sales are divided approximately equally between consumer products and industrial products such as copiers, calculators, cash registers, facsimile equipment, electronic typewriters, and hand-held computers.

In their home country, Japan, Sharp is number 2 in computers behind industry leader NEC. Why then, is Sharp practically a non-factor in the computer market in the U.S.? Two reasons. First, their current channels of distribution are primarily NOMDA (office products) dealers which, for the most part, have been less-than-successful in marketing computers. Second, Sharp's first computer entry some two years ago did not have the software that buyers were demanding.

Sharp thinks that the PC-5000 is the product that will turn all that around. We think they are right. It is significantly different from other products, and computer stores should jump over themselves to handle it. Sharp has a goal of availability in 800 computer stores by the end of 1984; we think that goal is modest, and that far more stores than that will want to handle the PC-5000.

Furthermore, Sharp is not planning any distribution through mass merchandisers. This will help to avoid the price wars now creating havoc in the low end of the market.

The software that Sharp has chosen to implement on the PC-5000 should answer the needs of most business and professional users. Furthermore, they currently have a wide array of peripherals and are committed to being competitive in that area.

So, from the standpoint of corporate strategy, Sharp seems to be on the road to success with the PC-5000. Moreover, they have the financial clout to stay in the market even if the going gets rough. But what of the product itself?

On The Outside

At first glance, one might be tempeted to say that the PC-5000 is just the next step in the evolution of notebook computers that started with the Epson HX-20 (screen: 4 lines by 20 characters, mini printer). Next came the Tandy Model 100 and NEC 8201 twins (screen: 8 lines by 40 characters, no printer but built-in modem). Then the Sharp PC-5000 (screen: 8 lines by 80 characters, 80-column printer, and integral modem).

But that is a vast oversimplification; the PC-5000 is far more. Indeed it is far closer in capability to a desktop computer than it is to a notebook machine. In many ways, it is more like an IBM PC than a TRS-80 Model 100. But like the Model 100, it is a battery-powered portable, and that is where we will start our evaluation.

Folded up, the PC-5000 measures 12.8 X 12 X 3.4 and weighs 11.02 pounds. That is about one third the weight of a Kaypro-type portable and three times that of a Model 100. Although 11 pounds sounds light, it is heavy enough to discourage you from carrying it everywhere.

Fitted into the top of the case is a direct-connect modem/telephone handset with several nifty features. It measures just 8 X 4 X 0.8 . More about the modem later.

Not included in the dimensions or weight of the basic unit is the AC power supply/charger. This is a hefty 12 volt, 850 ma. supply which measures 3 X 4 X 2.2 and weighs a bit over one pound.

The computer, power supply, bubble memory cartridges, printer ribbon and paper, modem cables, and manuals fit nicely in a standard attach[e case with room left over for additional papers or books. Sharp is working with American Tourister to offer a version of their standard 6 case with fitted cutouts for a complete PC-5000 system.

The front portion of the PC-5000 case pivots up and contains an LCD screen of eight lines by 80 characters. The active portion of the display measures 1.3 X 9.3 . This is smaller than the Model 100 display (2 X 7.5 ); thus to fit eight lines of 80 characters each requires a mighty small character size.

The graphics resolution of the screen is 80 X 640 pixels, each one of which is individually addressable from Basic using the PSET (on) and PRESET (off) commands.

Characters are formed within a 5 X 7 dot matrix, with two dots allocated for letter descenders and one dot for interlinear spacing. That means that each character is 0.15 high, the same as a dot matrix printer set to print six lines per inch. As we said, this is mighty small. This diminutive size coupled with the usual black-on-gray LCD display means that it is critical to adjust the angle of the display and the contrast of the LCD elements correctly (a thumbwheel is provided on the side of the case for this).

The PC-5000 is turned on with a rocker power switch at the rear. This calls up MS-DOS which allows you to choose one of the internal programs in ROM (for now, only Basic) or a program from any one of the devices accessible from MS-DOS. Input devices that can be accessed are bubble memory cartridges A and B, disk drives C and D, and a cassette recorder. Later, Sharp promises ROM availability of EasyWriter and some of the other Easy packages from BSG Software.

Bubble memory cartridges (128K each!) measuring just 2 X 2 X 0.3 are inserted in a slot at the top of the keyboard beneath a hinged cover. To the left of the cover are three small LEDs. A yellow one indicates that power is on, a red one warns that the battery is getting low and needs a charge, and a green one indicates that the bubble memory is being accessed (just like a disk drive indicator).

Standard Keyboard

Unlike so many other computers which have all kinds of extra keys in unexpected places, the PC-5000 keyboard is almost 100% standard with no unexpected keys to confuse a touch typist. SHIFT and TAB keys are double size where they belong, and the RETURN key is double height and width--again, where it belongs.

The only exception to the standard layout is the CAPS LOCK key which is to the right of the rightmost SHIFT key. As expected, it toggles caps lock on and off but it does not stay down when it is on. Thus, you must look at the screen to determine whether caps lock is on or not--a curious oversight in an otherwise excellent keyboard.

The alphanumeric keys are light gray with black markings, and the control keys are dark gray with white markings. The keytops are all matte finished and concave sculpted, a nice touch.

There is a slight "give' to the keyboard in the center, typical of keyboards mounted on a PC board supported only at the sides. It is not a major problems, but we think Sharp should consider putting in some additional supports, assuming they do not interfere with the circuitry beneath the keyboard. But as we said, it is not a serious drawback, and, in its current design, the keyboard has a better feel than the Model 100.

Above the alphanumeric portion of the keyboard is a row of 15 rectangular keys. The two at the left are orange and are marked ON/BRK and OFF. The OFF key temporarily puts the computer to sleep to await incoming modem traffic or program input, while the ON key awakens it. It also acts as a Break in Basic programs.

The next eight keys are function keys. These have different meanings in various software packages or can be user-set from either Basic or MS-DOS.

Continuing to the right, the next four keys are cursor control keys. Why did Sharp not lay them out in a logical diamond pattern as on the NEC 8201, but choose instead a straight line? We'll probably never know, but in our minds this is not at all user-friendly. To make matters worse, there is no space between the left arrow key and function key 8. Why is this bad? Because function key 8 is normally the one used to exit a program, and it is all too easy to hit it when you intend to hit the left cursor key--the one used most frequently. More than once we exited the word processing package inadvertently and turned TRACE on the Basic (function key 8) when intending to hit the left arrow.

The last key in the top row is an orange CLEAR/INSERT key. In both Basic and SuperWriter, insert is toggled on and off with this key. In Basic, when insert is on, the cursor (normally a one-dot underline) changes to a two-dot underline. It is canceled by hitting the INSERT key a second time, any one of the cursor keys, or the RETURN key. However, in SuperWriter, there is no indication on the screen that insert mode is on, and it can be canceled only by hitting the INSERT key a second time. We found this inconsistency somewhat disconcerting, and feel that the software packages ought to be consistent.

An ALT MODE key is at the left of the spacebar. It toggles the keyboard into an alternative mode which, in Basic, causes most of the keys to produce a Basic keyword such as GOTO, RESTORE, and PRINT. The various graphics symbols and foreign letters can be produced directly from the keyboard by holding down the SHIFT and toggling on the CAPS LOCK. This is less convenient than a single graphics key, but at least it provides keyboard access to characters above ASCII 128 (see Figure 1).

On The Inside

The PC-5000 is built around a 16-bit 8088 mpu. It has a whopping 192K of CMOS ROM memory, 64K for the operating system, and 128K for DOS and Basic. The basic machine is equipped with 128K of RAM; an additional 128K is available. As mentioned earlier, it has a slot into which a bubble memory cartridge (128K of non-violatile memory) can be installed. A very thoughtful feature is the warning that appears on the screen when the bubble memory is 97% full.

Also on the main bus are a real-time clock, external bus driver (for floppy disks or other external devices), audio cassette interface (1600 bps), RS-232 interface, modem interface (300 baud), as well as an address and data bus multiplexer. This latter item directs data to and from either the main 8088 mpu (actually very little goes to it) and the CMOS controller. This is an important function since the 8088 requires more power and runs hotter than the CMOS circuitry, so it is desirable to use the 8088 only for essential functions. (See Figure 2.)

Also on the inside are the printer controller, LCD display controller, and keyboard interface.

Connectors are provided on the back of the PC-5000 for cassette cables, external bus, RS-232, modem, and AC power supply

The PC-5000 can operate on either an AC power supply (which doubles as a charger) or an internal lead acid battery. Acid, acid? Why not NiCad like everyone else uses? Several reasons. First, an acid battery has a much longer shelf life than a NiCad. Second, it is smaller and lighter for the same power output. And third, it charges faster.

The battery provides eight hours of continuous run time--slightly longer if the machine is used intermittently. A full recharge takes about four hours. As mentioned, a red LED indicates when the battery is getting low. For the user on the move, an extra battery is probably a smart buy.

Bubble Memory Or Floppy Disk?

The PC-5000 has two types of external memory available, bubble memory and floppy disk. Obviously, in the portable mode of operation, bubble memory is the only choice. Each 2 square cartridge holds 128K, and preprogrammed bubble cartridges can contain applications programs or different versions of the operating system.

To the operating system, the bubble cartridge looks just like a double-density single-sided disk drive. MS-DOS recognizes the bubble cartridges as device A and B. Data is stored 512 bytes per sector, eight sectors per track. Bubble cartridges are formatted as delivered.

Also like a floppy disk, bubble cartridges can be write protected by placing a silver sticker on the right side of the cartridge. Like floppy disks, bubble cartridges should be treated carefully and kept away from strong magnetic fields. Like a disk, it is sensitive to temperature, and the bubble cartridge has a built-in temperature lock that prevents operation below 32~ or above 104~.

The disk drive available for the PC-5000 is the CE-510F, a double-density, double-sided 5 1/4 unit with a capacity of 320K per disk. The drive, of course, must be operated with AC power and is not portable.

Built-in Printer

The printer built into the PC-5000 is a thermal unit which uses individual sheets of either thermal paper or plain bond. It is simple to install the printer in the event it is not purchased with the basic unit. One cable connector, four screws, and a platen feed knob do it.

In the thermal mode of operation, you simply put a piece of thermal paper in the printer from the rear, turn the knob a few turns, and that's it. Paper loading was considerably simpler than with the thermal unit on the Computer Devices DOT machine. An automatic paper sensor halts printing when there is less than 1 of paper remaining.

There is a contrast selector on the printhead which can be used to adjust for the best output.

The printer can be set for either 10 or 12 characters per inch. At 10 cpi, print speed is 30 cps, and at 12 cpi, the speed is 37 cps. Thus a single spaced page takes approximately two minutes to print, not a speed demon, but no slouch either. Moreover, the thermal mechanism is whisper quiet. Four of us carried on a normal conversation around a table with the printer churning away in the center, something you couldn't do with a dot matrix unit.

To print on plain paper, a one-time thermal ribbon cartridge is inserted in the printer. In this mode of operation, the printed image is burned into the ribbon and transferred to the paper. It does not smudge at all and is similar to a good Xerox copy. As with a photocopier, rag bond or textured paper cannot be used; a smooth-finish copier paper gives the best results.

Although plain paper printing sounds wonderful, we think that thermal paper may be a better choice. Plain paper printing requires a one-time ribbon cartridge ($5.99). Moreover, the ribbon tension must be carefully adjusted; Figure 3 shows the result of it being slightly loose. Nevertheless, it is nice to have the capability for the few things that must be on plain paper.

The printer can print standard characters at 10 and 12 cpi as well as dot graphics in the same density as the display (640 dots per 6.67 line). See Figure 4.

Operating System

The standard operating system in the ROM of the PC-5000 is Microsoft MS-DOS. The system must be started with either a bubble memory cartridge or a disk drive installed. Whichever is installed becomes the system unti. If both are connected, pressing A or B selects the bubble memory and C or D selects a disk drive.

Upon a correct power up or warm start, the standard MS-DOS v. 2.02 dialog is displayed along with the current date. MS-DOS then looks for an autoexecute file which, if found, is executed. This is useful if you plan to use the machine mostly for word processing, spreadsheet calculations, or some other function. If there is no auto-execute file, MS-DOS displays the standard A> or C> prompt. You may then call up any utility, applications program, or other file.

MS-DOS has the expected utilities (copy, format, directory, delete, rename, etc.). Specific to the PC-5000 are commands to stop and resume scrolling on the display, turn on printer echo (to turn your PC-5000 into an expensive typewriter), set printer cpi, set the communications parameters, and put the machine to sleep.

GW Basic

As available on other 8088-based computers, the PC-5000 has Microsoft GW (Gee Whiz) Basic available. We have reviewed this before and will not go into the many extended features of this outstanding Basic.

Variables in GW Basic can be integer, single or double precision, or string. Default mode is single precision. In our benchmark, accuracy and randomness were the same as the TI Professional and Computer Devices DOT, and better than the IBM PC. Speed was excellent also. See Table 1 for some interesting comparisons.

GW Basic has six Boolean operators including XOR, EQV, and IMP. For program chaining, it has COMMON, CHAIN, and MERGE. For random-access data files, it has FIELD, GET, PUT, LSET, and RSET. USR calls machine language routines, but there is no documentation on writing machine language code. ON KEY tests to see if a function key has been pressed, and ON COMM activates a communications trap routine.

An interesting statement we hadn't seen before is OPTION BASE which sets the first value in dimensioned arrays to either 0 or 1. Arrays, incidentally, can have up to three dimensions.

The graphics capabilities are extensive and include PSET, RESET, and LOCATE (cursor positioning). CIRCLE automatically draws circles, ellipses, and arcs on the LCD screen.

The WAIT command halts program execution until a specific bit appears at a port you specify. The manual admonishes caution when using this command: "Be careful! You could wait forever if the bit you want doesn't appear.'

Limited sound capability is available with the tiny built-in speaker. BEEP provides a single tone while SOUND provides a tone of any duration with a frequency between 37 and 32767 Hz.

Word Processing

The standard word processing package supplied with the PC-5000 is SuperWriter from Sorcim Software. We have not evaluated Super Writer in Creative Computing and were unable to convince Sorcim to send us a manual, so these remarks are based on a few hours of use on the PC-5000 sans manual.

SuperWriter appears to be quite userfriendly and inadvertently pressing the exit key several times did not result in the loss or destruction of anything vital (like our text).

The package is completely menu driven, and does not seem to burden the user with extraneous or inexplicable commands. The screen wraps automatically and, no matter how fast you type, does not drop characters (like some other word processors we know). A plus sign indicates the last character on a screen line, a nice feature for keeping track of imbedded spaces.

Curiously, the display does not scroll. Instead, when seven lines have been typed, the text jumps up five lines leaving the previous bottom two lines as the top two lines on the new screen.

One not-so-friendly feature is that the cursor disappears if it is held down. What is actually happening is that the cursor is moving in the direction specified, only to reappear when you release the key. Reappear where? Well, as far as it has traveled while the key was depressed which might be three characters away or 30 characters or 100 characters. We quickly abandoned the cursor repeat feature in favor of individual keystrokes to move the cursor exactly where we wanted it.

An insert mode is available but, as mentioned earlier, the cursor does not change size or shape, so you have no idea whether you are in insert mode except by looking at what you are typing.

Nevertheless, despite these minor shortcomings, we judge SuperWriter to be a good, solid word processor, and one that is well-suited to the PC-5000.

Sharp tells us that before too long, EasyWriter from BSG Software will also be available in ROM for the PC-5000, thus giving the user a choice between two excellent packages.

Applications Software

Two other packages from Sorcim are also available on a separate bubble memory cartridge, SuperCalc-2 and SuperPlanner. Thus for users with the need of a spreadsheet, at least one is available immediately.

In addition, Sharp informs us that 17 other software houses are currently working to covert one or more packages to run on the PC-5000. Given the host environment of MS-DOS and a screen width of 80 characters, it shouldn't be too long before many of these packages are available.


Communications on the PC-5000 is accomplished using the CE-510T modem/dialer. This is a 300 baud direct-connect unit with a built-in dialer, speaker, and microphone. The modem stores up to ten 16-digit telephone numbers which can be dialed automatically by pressing one button. Of course, numbers may also be dialed manually. In case of a missed connection or busy signal, a recall button is also available.

Unlike other modems, the CE-510T has a speaker and microphone built in; thus it can be used as a standard handset or, when placed flat on a table, as a conference phone.

To use the computer in a communications mode, a communications software package, SuperComm by Sorcim, is provided with the basic unit. The modem, however, is not included with the computer; it is an extra cost ($349) item.


Documentation with the PC-5000 consists of a User's Guide, Basic manual, and manuals for SuperWriter and SuperComm.

We had preliminary documentation with our evaluation unit so we can comment only on the content of the manuals and not their final appearance or size.

The User's Guide has seven chapters and seven appendices. The chapters cover the components of the PC-5000, setting up, installing the options, starting up, installing and using the printer, and a very long chapter (more than 60% of the manual) on MS-DOS. The manual is comprehensive, clear, and well-illustrated with scores of photos and diagrams.

The Basic manual is the usual Microsoft GW Basic manual customized for the PC-500. It has six chapters covering editing, structured programming (aw, come on now), statements, commands, and functions. As we've said before, this is not a substitute for a good Basic programming text, but mainly is a reference guide to the particular implementation.


Service, if needed for the PC-5000, is available from most (but not all) selling dealers. More interesting is a program called EXTRA (Extended Time Replacement Agreement) available to either the dealer or end user. This provides three options: (1) mail or carry in to one of the five Sharp regional service centers for repair, (2) Over-the-counter exchange at a regional center, and (3) next business day replacement direct from Sharp.

EXTRA also gives the user access to a toll-free telephone line for hardware and software advice. Dealers using EXTRA can telephone a special number that will download diagnostic routines into a computer; we can forsee the day when this will be made available to end users.


The basic PC-5000 with 128K, MS-DOS, SuperWriter, and SuperComm sells for a suggested retail price of $1995. Other components are priced as follows:

128K Bubble memory $269

Modem/dialer 349

Printer 399

Dual floppy drive 999

64K RAM upgrade 169

SuperCalc/SuperPlanner on 182K bubble 369

We see the most desirable configuration for protable use being the basic unit with printer and SuperCalc extra bubble memory--total cost, $2763. If it is your only computer, the floppy drives are probably necessary, for a total of $3762--rather heady for a portable compared to the TRS-80 Model 100, but quite a bargain compared to an IBM PC or high-end portable such as a Gavilan ($4000 plus) or Grid Compass ($8500 plus).

The Bottom Line

Frank Barbosa, General manager of computer systems at Sharp, confided to us that they were having a difficult time deciding how to position the PC-5000 in a 30-second TV commercial. Now, having used the machine, we see the problem. Is it a full-capability 16-bit desktop computer in a compact package? Sure is. Is it a notebook computer with full-size features and power? Yup. Is it a state-of-the-art machine with bubble memory, nity modem, big LCD display, and whisper quiet printer in an 11-pound package? Right on.

That is not to say that the PC-5000 is perfect. It isn't. The cursor control keys should be arranged in a logical diamond pattern. It would be nice if the LCD screen were somewhat larger. The keyboard should have more support in the center and the CAPS LOCK key should give some indication of being depressed. And the software packages should be consistent from one to another.

But frankly, these problems are nits against the astonishing capability, speed, and memory capacity of the PC-5000. Furthermore, Sharp is a large, profitable company with an excellent service organization. The outstanding use of state-of-the-art technology coupled with well-proven software augers well for the success of the Sharp PC-5000. Would we buy one? You bet!

Table: Speed and accuracy of selected 16-bit and portable computers.

Photo: Sharp PC-5000 opened in operating position.

Photo: Buttoned up, the PC-5000 measures about 12' square.

Photo: In the word processing package, plus signs designate the end of rows. Text is in a bold display face while the bottom line of functions is in the "normal' display face. Photo is actual size.

Photo: Keyboard has 57 full-stroke keys arranged in a standard pattern, and 15 special keys in a line above.

Photo: Review set-up. We took notes on paper and a Model 100 about various aspects of the Sharp.

Photo: Pc-5000 and power supply in fitted attache case.

Photo: Figure 1. A portion of the character set of the PC-5000 as printed by the internal printer on thermal paper.

Photo: Figure 2. System block diagram of the PC-5000.

Photo: On the back of the PC-5000 is the on/off switch and connectors for RS-232 devices, serial I/O, external bus, cassette recorder, and AC adapter.

Photo: Photo shows bubble memory cartridge compartment with cover open, three LED indicators, and poor horizontal arrangement of cursor control keys.

Photo: Bubble memory cartridge is just over 2 square.

Photo: The PC-5000 with optional 5 1/4 floppy disk drive.

Photo: Figure 3. Print sample on plain paper shows partial type at the ends of some lines, the result of the tension of the printer ribbon not being adjusted correctly. With the correct tension, print quality is excellent.

Photo: Figure 4. Printer is capable of producing dot graphics. This sample was done on plain paper.

Photo: With optional thermal ribbon, the printer can use plain bond paper as well as thermal paper.

Photo: Optional modem fits into the lid of the case. It doubles as portable conference telephone.

Products: Sharp PC-5000 (computer)