PX-8 | Everygamegoing

Personal Computer News


Published in Personal Computer News #061

Epson streaks back into the portable micro race with the PX-8. Peter Jackson rates it ahead of the field.

Epson Elaborates

Epson streaks back into the portable micro race with the PX-8

It must have been galling for Epson to find its ground-breaking HX20 lap-held computer being overtaken by the Kyocera bandwagon containing Tandy and NEC. Not to mention the brand new bandwagon started by Sharp with its MSDOS and bubble memory portable, the PC-5000, already reviewed in PCN (issue 51).

These machines have more memory, bigger and better displays, and bundled software, and the HX20 found itself relegated to being built into Daimlers as an executive toy.

The PX-8, first shown at Hanover and launched in the UK this week, is Epson's long-awaited response. All the Kyocera and Sharp lessons have been learned, and the founder of the market is back in there slugging.

In fact, the PX-8 leapfrogs all the competition except Sharp and is cheaper than that upmarket machine. It forms the heart of a complete system, with 64K RAM, 80-column by eight-line LCD display, and battery-powered acoustic coupler, printer, and 3.5" floppy drive options. The company claimed before launch that it would be offering a complete CP/M system including a set of standard software for around £1,200. That doesn't sound too great, but *this* CP/M system will fit inside a regular briefcase.

First Impressions

Looking at the specs, the first thing to meet the eye is that the PX-8 is a real CP/M machine, with that familiar Digital Research trademark message all over the place. And the decision to go CP/M has governed the hardware that goes into the box. It has also brought the desktop battle between Digital Research and Microsoft into a new area - Tandy, NEC and Sharp all use operating software from Microsoft - but that's another story.

In particular, using CP/M means that the main processor in the PX-8 is a Z80; or, to be more precise, is a "Z80-compatible CMOS CPU." Two extra CPUs do special jobs in the machine, a 6301 "slave CPU" with 128 bytes of RAM and 4K of ROM on chip, and a uPD7508 sub CPU". The 6301 (the main processor in the HX-20) controls the display, with 6K of external video RAM holding the screen contents, and the on-board analog-to-digital converter. One thing the sub-CPU *does* do is the master reset; pressing the sub-CPU reset button puts the big stop on everything in the machine, and should be avoided except *in extremis*.

Inside the basic case is 64K of user RAM and 32K of ROM holding CP/M2.2 and the other operating routines. Another 64K of ROM space, in the shape of two sockets for 32K chips, is also provided. Interestingly, since CP/M is basically a disk operating system, up to 24K of the main 64K RAM can be set to act as a RAMdisk drive that CP/M treats as an ordinary disk drive. The default is a 9K RAMdisk segment, but the user can change this to any value from 0K to 24K.

Interfaces are on board for the built-in microcassette drive a la HX20, two serial ports, a bar code reader, an external loudspeaker, and analog input. Epson is particularly excited about the analog input, and sees the machine being used in industrial control applications.

One of the two serial ports goes up to a speed of 38,400 bits per second, and is intended to connect external floppy drives, either battery-powered 3.5" or mains-powered 5.25". This can also drive a printer at speeds of 4800, 600 or 150 bits per second. The other port is for RS232C hardware, and this goes up to 19,200 bits per second for conncetion to acoustic couplers, modems, or other computers. Unfortunately, both ports have extremely non-standard 8-pin DIN-style sockets so the interface cables will have to come from Epson itself. The company has a range that fits, covering the different hardware that can be plugged in.

The system bus also comes out to a connector in the back panel, and this is the key to the PX-8's outstanding feature. An external box screws on the bottom of the main case and plugs into the bus, and gives an extra 60K or 120K of RAM that the machine treats as a disk drive. If this is fitted, it stops any of the main RAM being used as a disk as described earlier; but I'll come back to the RAMdisk features of the PX-8 when we get to the software, since it governs the way the machine actually works.

The hardware is solidly made and seems from a few weeks' hard use to be as reliable as Epson kit normally is. A lot of work has gone into the system design, and in fact one ex-Epson executive told me that the Maple - the internal codename of the PX-8 - could have been out a lot earlier. My feeling is that the company, with typical Japanese thoroughness, wanted to get the machine and its supporting add-ons exactly right before launch. At least we haven't had the kind of launch the Sharp PC-5000 had, where the machine was shown at the NCC in California last May with no-one, least of all Sharp staff, knowing when it would be out or what the price would be.

My review machine came out of stock at Epson UK, and despite its low serial number (000026) I am assured that it is a full production model.

In Use

On first sight, the travelling PX-8 looks like a transistor radio, or some kind of high-tech handbag in two-tone beige. But sliding off a cover reveals the familiar HX-20-style keyboard, and the carrying handle slots neatly in under the keyboard and disappears from view. A sliding catch releases the screen and it can be clicked round its pivot to the desired viewing position.

Even this simple operation gives a hint of Epson's attention to detail; a small spring-loaded stud forces the screen up slightly when the release catch is pressed, just to make it easier to lift the screen. And the edge of the screen is fluted, with a thumbnail slot, to make it easier still.

The screen pivot is very solid and showed no signs of loosening at any angle during use. Epson provides a screw at the end of the hinge, presumably for tightening the pivot, but I had no need to touch it.

Lifting the screen reveals the built-in microcassette drive, the feature that distinguished the HX-20 from its later competition. The introduction to the manual informs us that 'Microcassette' is a trademark of Olympus Seiki, and the tapes supplied with the review machine did indeed have Olympus labels. But they seemed standard enough.

Without the wedge-shaped RAMdisk add-on the mcahine sits rather flat on the desk or lap, so two swivelling stands are provided to tilt the keyboard to a more convenient position. Fitting the RAMdisk covers these stnads, but the way the add-on box is shaped does the same job. The RAMdisk case is also designed to leave the ROM slots free, and a small clip-on panel under the keyboard gives access to these.

Delving around in the packaging brought up two very hefty A5 manuals and an AC adaptor, but since Epson had thoughtfully put in the NiCd main battery pack I just turned on the main power switch on the side of the case to see how CP/M looked on a battery-powered machine.

After a beep from the on-board loudspeaker - the volume control is next to the power switch - the initial display comes up on the LCD screen. As with all LCDs, the angle of view and lighting of the display are critical. A view angle slide control is mounted on the display surround, and I found that the best results came from tilting the display a long way back and changing the view angle switch to give the highest contrast possible. This makes best use of the ambient light, and gives a clear display of a very legible character set.

As with the NEC and Tandy machines, the first display was a menu of available files. However, here the files look like a standard CP/M directory - with a few important changes. Instead of getting just the directory of the current logged drive, the menu gave a list of all the files in the system with the CP/M 'COM' extension denoting machine code programs. That included, according to the menu, files on drives A:, B: and C:. Time to look at the manual to find out how these drives are arranged.

As it turns out, the arrangement of the drives is up to you, and you can even select the files that appear on the initial menu by entering which file extensions have priority, and which 'drives' the menu files are to come from. Pressing Control-Help brings up a separate system control menu that lets you set the initial menu contents, as well as allowing the entry of things like a system password, and the setting of alarm or wake times. The alarm function interrupts any program at alarm time and puts any required message on the screen; the wake function starts running any program at a set time: useful to telephone a file to Japan in the middle of the night.

The default disk configuration has the RAMdisk, either external or internal, as drive A: The two 32K ROM sockets are drives B: and C:, while the microcassette drive is drive H:. Two other configurations can be selected, which put one or two external floppy disk drives at the top of the list as drive A: or drives A: and B:. Up to four external floppies can be fitted, but the second pair are always at the bottom of the list as drives F: and G:. In all configurations, H: is the microcassette.

The system menu is built-in, but the disk configurations are part of a much bigger configuration program supplied by Epson as part of its stack of ROM-based software.


Tandy and NEC launched their Kyocera-made machines with bundled software from Microsoft covering Basic, word processing, diary, rudimentary database, and communications functions. But Epson's use of CP/M means it can bundle in the same functions using standard and familiar packages. Most of these come from MicroPro in the US, who have supplied Portable WordStar, Portable Scheduler, and Portable Calc in collaboration with Epson. Epson itself provides a communications package called Term, and a file transfer package specifically designed to swap files between the PX-8 and Epson's QX-10 desktop machine.

And Epson UK has struck its own deal, to bundle Business Simulations' Cardbox Plus database package with the PX-8.

The lateness of this last deal meant that Cardbox Plus for the review machine was supplied on microcassette, but all the rest was supplied in ROM cartridge. Actually, cartridge is too strong a word since the 32K ROM chips were simply fitted to plastic chip carriers to fit in the spare ROM sockets under the keyboard. There were four ROMs in all; one with the Microsoft/Epson Basic, one with WordStar, one with Portable Scheduler and Calc, and one full of CP/M utilities.

It's obvious that four ROMs into two sockets won't go, but with the big 120K RAMdisk fitted, that is no problem. Files can easily be transferred from the ROMs - normally drives B: and C: - to the RAMdisk using the CP/M PIP program provided in the utility ROM. PIP itself can be PIPed to RAMdisk to make this easier, and I found it simple to put the contents of two of the four ROMs into RAMdisk and plug the other two into the slots. What combination of ROMs is used is up to you.

Changing ROM cartridges is not the easiest thing in the world, but the carriers mean that it is impossible to get the chips in the wrong way round and it does not cause too many problems. One drawback is that the master reset button is next to the sockets, and can easily be pressed by accident. Epson promises that a plastic cover will be put over the button in every machine shipped.

But even this reset is not entirely disastrous. There are actually three resets in the machine, the master, one that just resets the RAM without clearing down to system level, and one on the RAMdisk box. The RAMdisk even has a write protect switch.

As expected, loading Cardbox Plus via microcassette took an age, but once again this can go into the big RAMdisk and be immediately available. One nice feature of using the cassette is that the directory of drive H: is stored in RAM when the cassette is mounted, and so is instantly available. But loading 30K to or from a cassette is an astonishingly slow process.

The performance of the software is naturally limited by the size of the display, but the packages use the space well. Epson provides software to configure the screen in various ways; there are two virtual screens in memory, and you can switch from one screen to the other by pressing Control with the right or left arrow key. Each screen can also be divided into two 39-column screens with separate contents. All the bundled packages use these features to a greater or lesser extent.

WordStar is just WordStar, with all the features you would expect. The only limitations that I could find as a long-time WordStar user were the lack of a directory display on call and the dropping of a lot of the help functions. The famous WordStar command menus are still there, but have to be called up separately using the Help function key since each menu completely fills the screen.

The Calc is just like SuperCalc in its commands, and seems to work all right although I am not a spreadsheet connoisseur. The Scheduler is nice, with a diary covering a month from the current date and time and monthly display that shows a chart of all engagements.

Cardbox Plus once again looks like its normal self with a few frills removed, but the commands the same. I found no trouble in using it despite limited experience with the package.

The Basic is standard Microsoft, with the addition of a few commands to do things like change the screen format, and the Utility ROM contains all the standard CP/M programs like STAT, PIP, XSUB and SUBMIT as well as Term, Filink, and the machine configuration program called, not surprisingly, Config.

Config lets you change the disk drive assignments, but it also allows the setting of the automatic power-off timing, the 10 function keys, the date and time, the printer port speed, the size of the RAM disk, the RS232C speed and transmission format, the screen mode, the serial port speed and format, the user BIOS - letting the user configure CP/M - and the keyboard layout and display for various countries. In other words, Config give just about as much flexibility as most users could ever want.

Not having a QX-10, I didn't try Filink. But Term worked fine in transferring WordStar files onto an Osborne running the Microlink comms package, and it was very simple to use. That's more than can be said for Microlink.

All the software is friendly and simple, and uses the facilities of the machine extremely well. Perhaps getting the software right also caused part of the delay in getting the machine out.


Epson has reacted well to recent developments in the lapheld computer market, and has come as close to the state of the art as you can get. The choice of CP/M might seem a backward step when Sharp has gone for the 8088 and MSDOS, but there is a lot of life in the 8-bit machine at this level. The provision for standard floppy disks means that the PX-8 can load standard CP/M software, as long as the screen format is not too much of a limitation. And the availability of the big RAMdisk means that real portable computing with big data files is possible without resorting to microcassette. In fact, the PX-8's cassette drive seems a bit irrelevant apart from archival use and for once-and-for-all loading of programs for people without disk drives.

But the most impressive thing about the machine is its flexibility, allowing you to configure everything to suit your needs.

To put it bluntly, I liked it a lot. On this particular computer bandwagon, Epson is back in the driver's seat.


Price: Basic model, 64K RAM - £917.70 inc VAT, with extra 120K RAM - £1,148 inc VAT
Processor: Z80 CMOS at 2.45MHz
RAM: 64K Basic, 60K and 12K RAM packs available
Keyboard: 72 full travel keys including cursors and functions. Seven character buffer
Screen: 80 x 8 characters, 640 x 64 dots
Storage: Built-in microcassette with directory
Operating System: CP/M
Software: Wordstar, Cardbox Plus, Microsoft/Epson Basic, Scheduler and Calc
Interfaces: RS232C, serial, barcode interface, analog input and speaker output
Power Supply: Rechargeable NiCd batteries
Manufacturer: Epson (UK) Ltd, Dorland House, 388 High Road, Wembley, Middlesex HA9 6UH. Tel: 01-902 8892

Peter Jackson