Panasonic JR-200. (evaluation) David H. Ahl.
The Panasonic JR-200 personal computer from Matsushita has been several years in the making. We have seen versions of it at the last two Consumer Electronic Shows. Now, it is finally being released; it was worth the wait.
Outwardly, the JR-200 has modern, pleasing styling. The case measures 13.5 X 8.0 and slants from a height of 1 in the front to 2 in the rear. Made of plastic and finished in silver and matte black in the keyboard area, the case is rugged and durable. We carried it in a fabric tote bag from Las Vegas to Morristown to Phoenix to Orlando and back to Morristown with no ill effects.
The power switch is recessed on the left side of the case; a red power on indicator is on the top right. The power cord is permanently attached at the right rear. In contrast to several other small computers, the transformer and power supply are completely self-contained. Also on the rear of the case are six connectors of various sorts.
Connectors and Switches
Two connectors are provided for the video display. An eight-pin D.I.N. connector attaches to a cable (included) which goes to an NTSC composite video or RGB monitor. An RCA jack provides an RF signal on channel 3 or 4. Interestingly, this signal is provided at a 75-ohm impendence and the supplied 6-foot cable has a quick disconnect F Connector at the TV end. Most current TV sets have a 75-ohm F-type input; on such sets the JR-200 produces a crisp, clear image, almost of monitor quality. For some strange reason this image deteriorates noticeably if this output is routed through a 75 to 300-ohm transformer and fed into standard antenna terminals. This seemed odd so we tried it on five different make TV sets with the same result--outstanding with a 75-ohm F input, mediocre with a transformer.
Another RCA jack provides 8-ohm audio output to an external speaker. Next to it is a volume control which controls both the volume of the external and 1-1/2 internal speakers. Audio power is more than adequate; people in the rear of a 100-seat conference room had no trouble hearing the internal speaker during a demonstration. While JR-200 is theoretically capable of producing tones in the range of 0 to 65535 Hz, only dogs will be interested in sounds in the upper three or four octaves. Realistically, the usable sound range is about five octaves, an impressive achievement in a computer of this size.
A second 8-pin D.I.N. connector is for a cable (included) to a tape recorder. The cable has three jacks for input (earphone), output (microphone), and motor control. A DIP switch on the bottom of the case selects either 600 or 2400 bps. We were pleased to find that the JR-200 performed reliably at 2400 bps on modest quality ($19-$29) recorders over a reasonable range of volume settings on standard tape. This is in sharp contrast to many other computers which require precise volume and tone settings on a high quality recorder using premium tape.
Two other connectors on the rear of the JR-200 connect to a printer and external bus. Via this bus, the JR-200 has a serial RS-232C port which may be set up for half or full duplex, 7- or 8-bit words, and odd, even, or no parity. JR-Basic does not use the standard format for RS-232C communications. Although data may be transmitted by using the OPEN-INPUT#/ PRINT#-CLOSE statements, the user must develop a routine that will send or receive data on the end of the line. JR-Basic does not have EOF (end of file) when using RS-232C communications.
The keyboard has 63 "Chiclet' style rubberized keys in standard typewriter layout. The keys are 1/2 square and the spacing is identical to a standard keyboard. A full-width (5 ) spacebar is provided along with two double-width shift keys and a double-height return key. All the keys are in the expected places.
The standard alphanumeric and symbol keys are all matter finished in dark gray, function keys (shift, return, cursor movement, etc.) are blue, and the control and break keys are white.
Each of the gray keys can produce five inputs: an upper- and lowercase letter (or number and symbol), two graphics characters, and a Basic keyword. Two keys, ALPHA and GRAPH, are used to switch back and forth between character and graphics modes. Holding down the CON-TROL key while pressing a gray key produces a Basic keyword.
In total, the JR-200 has 253 built-in characters: 96 English letters, numbers and symbols; 5 Greek letters; 63 graphics characters; 79 Katakana (Japanese) symbols; and 10 music and other symbols. All told, this is an exceptionally rich character set, right down to the inclusion of a happy face and stick figure man. All the symbols are formed within an 8 X 8 matrix of pixels.
According to the specifications, it is possible to define your own characters. However, the preliminary documentation we had did not describe how to do this so we couldn't try it out.
Although the keys do not provide any tactile feedback, each keystroke is accompanied by a beep. All keys with the exception of CONTROL, SHIFT, RETURN and BREAK repeat rapidly upon being held down for about two seconds.
The screen display is 32 characters by 24 lines. Each of the 768 locations can be individually addressed with the LOCATE (x, y) command. As mentioned earlier, each symbol and character is formed by lighting pixels within an 8 X 8 matrix, hence by using the correct combination of graphics characters, it is possible to achieve very high resolution images, up to 256 X 192 if you are clever.
Medium resolution (64 X 48) is much more easily achieved by use of the PLOT (x, y) command which permits direct addressing of one-quarter of each character.
PLOT would normally be used in conjunction with COLOR which allows selection of character color, background color and display mode. Four display modes are available: normal, user-defined characters, inverse color of previous characters, and alter background color for positions following the cursor. When we got the hang of it, we found the COLOR command very powerful for producing interesting, and occasionally bizarre, effects. See Figure 1.
Eight colors are available for foreground and background use: blue, red, magenta, green, cyan, yellow, white, and black.
The JR-200 is capable of producing sounds ranging from simple to complex. The simplest way of getting a sound is with BEEP 1 which turns on the beeper (880 Hz or A above the middle octave). It stays on until a BEEP 0 is encountered which turns it off.
One step above BEEP is SOUND (P, L) in which P is the pitch in Hertz (0 to 65535) and L is the length of the tone in milliseconds (0 to 255). This is very easy to use in a program.
More complicated are the PLAY and TEMPO commands which permit playing tunes with up to three parts over a 5-octave range at any imaginable tempo. Notes are stored in memory and may be played either in foreground (pauses program) or background (program continues) mode.
As you may have surmised by now, JR-Basic is not Microsoft Basic, but it is not far away either. Most of the commands, statements, and functions are identical or very similar. Rather than going through JR-Basic in detail, we will simply highlight some of the more interesting and novel features.
As expected, JR-Basic has immediate mode and will execute most Basic commands directly from the keyboard singly or in groups (separated with a colon) as long as the maximum line length of 80 characters is not exceeded.
When the JR-200 is fired up, a copyright notice appears along with the number of free bytes. In all configurations, 2052 bytes are reserved for the Basic work area and the remaining RAM is available to the user. We used a 32K machine and thus had 30,716 bytes free. User memory can be expanded to 40K. Basic occupies 16K of ROM while video RAM, I/O and the built-in character set occupy another 6K plus.
A requirement of JR-Basic is that Basic keywords be separated by at least one space or a colon or semi-colon from other characters. While this requirement is imposed by the internal interpreter, it also enhances the readability of finished programs.
Numeric values can range from 2.9(-39) to 1.06(38) and are stored and displayed with nine digits of accuracy. Don't ask me how. Both numeric and string variable arrays can have one or two dimensions. Unfortunately variable names are restricted to two letters or a letter and a number.
All the standard operators are available: arithmetic, relational, logical and string concatenation. As expected, LET is optional.
Although the RENUM (renumber) command is listed in the manual, it steadfastly refused to work on the JR-200 we tested.
RUN performs its usual function but can slso be imbedded within a program to run another program or to run the existing program from any specified line number, e.g., RUN 480. When used with a filename (RUN "Border'), it will load the program from cassette tape and then run it.
The functions HPOS and VPOS return the current horizontal and vertical position of the cursor respectively. PEEK lets you examine any memory location; its counterpart, POKE lets you put a value into a location. An unusual function is VARPTR which returns the memory location where a particular variable is stored.
A delightful feature of the JR-200 is full on-screen editing. To correct a mistake or make a change you simply list the line or group of lines to be changed, and use the four directional keys at the right of the keyboard to move the cursor to the character to be changed. At this point you can type the change or use the insert, delete or rub out keys to make changes. You then move the cursor to the end of the line and type RETURN. Whoosh; the change is made.
The only time we ran into trouble was when a change extended a line so that it overlapped the next line down. If you are not careful in a case like this, you can wipe out both lines. The solution? Don't press RETURN. Unless program lines are short, the best bet is just to list one at a time for editing or use the LINE INSERT key to open up a new line after the one being edited.
Another handy editing feature is the FIND command. It will search for a string of characters and list the line(s) with that combination of characters. For example, FIND "FO' would list all the FOR statements in a program plus lines containing any words with FO (in caps) in them. LFIND performs the same function but lists the lines on the printer.
Tape Handling and Files
Programs are loaded with either LOAD or LOAD "Filename.' A program must be saved with a filename specified.
Files or other material may also be saved and loaded directly from and to memory with the commands MSAVE and MLOAD.
A very handy feature is the ability to load one program at the end of another. This is done using the MERGE command. Of course, if the programs use the same line numbers, only the most recently loaded one will survive.
Another handy command is VERIFY which checks to see if a program in memory and on cassette tape match.
Files of data (not programs) may be stored sequentially on cassette tape using the PRINT # command, and read back with the INPUT # command. While sequential tape files are not nearly as handy as random access disk files, the 2400 bps I/O speed is quite tolerable and such files are probably suitable for lists of names and addresses, items in a collection, and the like.
We did not have a printer with our JR-200, hence, we can only note that the manual lists five printer commands. Two are the expected LPRINT and LLIST. A third, HCOPY, generates a copy of the video display on the line printer. This presumably includes graphics, but we can't say for sure.
The last two commands are TAB which tabs over from the left margin and SPC which spaces over from the last cursor position.
The JR-200 has two DB-9 sockets on the left of the case which accept standard Atari-type joysticks. Values from them can be read into programs by means of the STICK function.
The JR-200 allows machine language aficionados to get into the monitor and the assembly language.
The monitor has only three commands: D, M, and G. D displays 128 bytes of memory from the location specified. M sequentially lists the memory locations from the address specified and allows you to alter them. G begins execution of an assembly language program from a specified address. Memory locations are all in hexadecimal.
Since we had only the scantiest information about these commands and none at all about JR-200 assembly language, we did not check out this feature.
Software and Support
From talking to Robert Zangrillo at Winter CES, we know that Panasonic is sincere in trying to provide support for the JR-200. All the early machines have been put in the hands of software developers such as Datamost, a smart move for getting third party software on the market. Also Datamost has produced a version on their book, Kids and the Apple, for the JR-200. Likewise, we are in the process of producing a volume in our ideabook series for the JR-200, The Panasonic JR-200 Ideabook.
On the other hand, the preliminary JR-Basic manual is tough going, has very few programming examples, and could in no way be considered user-friendly. We are told that the Datamost book will be supplied with the JR-200 as the Basic programming primer--probably a reasonable approach.
The Panasonic JR-200 is one of the nicest new computers to make the scene in some time. It is attractively styled, is easy to use, and boasts an excellent, if not standard, Basic language. The graphics are very approachable and although resolution is not exceptionally high, the character set is excellent and allows the creation of detailed images. The keyboard is among the best of its type and the separate cursor movement keys make onscreen editing a joy.
The JR-200 is cassette tape oriented and uses it well for program and data storage. We are disappointed that Panasonic does not seem to be moving in the direction of a low-cost compact floppy disk unit.
Peripherals, documentation, software and support are, at this time, question marks although Panasonic appears to be moving in the right direction on all fronts. At the suggested list price of $350, the JR-200 is an excellent choice.
Photo: Figure 1. Program shows the use of COLOR and PLOT to produce a series of different colored concentric borders starting at random points in the upper left quarter of the screen. Note the clever way of putting the PLOT statements for all four sides in a single FOR loop.
Photo: Separate cursor control keys make on-screen editing a joy.
Photo: The JR-200 is a compact 13-1/2" X 8".
Products: Panasonic JR-200 (computer)