SpectraVideo SV-318 and SV-328. (evaluation) David H. Ahl.
The SpectraVideo family of computers is an interesting international effort. Overall management, marketing, and direction come from the company headquarters in New York; systems software development including the powerful implementation of Microsoft Basic was carried out by ASCII Microsoft in Tokyo; while the manufacturing is done in Hong Kong. The SV-318 and SV-328 are the products of this unusual, but highly successful three-way marriage.
While this is a review of both machines, we will generally speak of the computer (singular) and point out the differences between the two models (built-in memory and keyboard) in the appropriate places. Functional Console
The computer is housed in a sturdy white plastic case measuring 15.5" x 8.7" which slopes from a height of 1.7" at the front to 3" at the rear. Imediately visible on the top of the case is the keyboard and a red LED indicating that the power is on. Although a small feature, this is much appreciated; so many computers today provide no indication of whether they are on or off.
Also on top of the case is a hinged cartridge port in which to plug in software packages that come in cartridge form.
Moving to the right side, we find a male 4-prong power supply input. The power supply is a heavy duty unit providing 14 volts at 2 amps and 8 volts at 3 amps. This is three to four times the power offered by the average home computer power supply; thus it ought to more than enough reserve power for all the peripherals you may ever want to add.
Also on the right side are a rocker-type off -on power switch and two game controller ports. These are standard DB-9 receptacles for Atari-type joysticks, paddle controls, and track balls.
On the back of the console are an expander port, cassette port and video output port. An RF modulator furnished with the system plugs into the video port and, according to the specs, will produce NTSC, PAL or SECAM output as appropriate. It uses a standard 5-pin, 180-degree DIN connector which can be easily wired to provide a composite video signal to a monitor with separate audio output.
The cassette port connects to the Spectra Video stereo data/audio cassette recorder. The computer has lines for sending and receiving data, motor control, and power.
The expander port allows the computer to be connected to a single slot expansion adapter or a 7-slot expansion box. More about this later. A Complete Package
The attractive box contains nearly everything you need to start computing. You get the computer/keyboard unit, RF modulator (with 3' cable), shielded video cable (5'), video switch box, power supply, instruction manual, and warranty card.
The manual has eight pages of photos depicting all aspects of hooking up the system and getting it into operation. Another helpful feature is the built-in diagnostic check that automatically occurs upon powering up the system. A successful self-test is signaled by a beep in the TV speaker about 1-1/2 seconds after turning on the power switch.
Upon a successful power up, the SpectraVideo logo appears in three colors followed by a message indicating the version of Microsoft Basic in the system and the number of free bytes of user memory. A standard SV-318 has 32K of RAM; 16K is allocated to graphics support and the other 16K is user addressable memory. Well, not quite; 3569 bytes are reserved for overhead, I/O, and the like. Thus an unexpanded 16K SV-318 has about 12.5K truly usable bytes and a standard 32K SV-328 machine has 29.2K. Both computers are expandable, with 16K or 64K external memory packs, to a maximum of 256K. Computer/Keyboard Unit
The SV computers use the Z80A mpu chip operating at 3.6 MHz; until recently, most personal computers used a 2 MHz clock rate. In theory, this should make the SV computers faster than other comparable machines. In practice, the issue of speed is somewhat more complicated.
The version of Microsoft Basic used by the SV computers automatically makes all variables double precision. Hence, a variable occupies eight bytes, and every time it is called, those eight bytes must be moved. In contrast, most other small computers use single precision variables (four bytes) so there are correspondingly fewer memory accesses when a variable is called. The bottom line is that in a normal Basic program, the SV computers are considerably more accurate than, say, the Mattel Aquarius or TRS-80 Model 4, but only about half as fast. A slight improvement in speed (about 10%) can be obtained by defining variables as single precision.
On the other hand, the speed advantage is apparent when using machine code. Also, as we will see later, the inclusion of several powerful Basic and graphics commands makes programming much simpler, particularly for animated graphics. This may yield a speed advantage as well, since one command does the job of many.
The keyboard on the SV-318 has 71 rubberized Chiclet-style keys. In addition to the expected alphabetic, numeric, and symbol keys, the keyboard has five function keys, three program control keys (STOP, ENTER, and CONTROL), and six miscellaneous keys.
Each of the five control keys activates two functions depending upon whether SHIFT is pressed. The function of each of these keys is shown on the bottom of the TV display. The functions controlled by these keys are color (to set character, border, and background colors), auto line numbering, list (the entire program or the last line you were working on), run, cassette load, GOTO (allows execution of a program from any point), and continue. In addition, all ten of the function keys are user programmable with a simple statement, for example, KEY 1, "Creative". From then on, whenever function key 1 is pressed, the word Creative will automatically appear.
The six miscellaneous keys are caps lock, clear screen and move cursor to home position, insert, delete, And left and right graphics. These last two keys are used to select the 52 graphic symbols on the keyboard (each of the 26 letters can produce two graphics symbols).
To the right of the keyboard on the SV-318 is a joystick/cursor control pad. A joystick may be screwed into the center of the pad for use in games or to move the cursor around the screen in any of eight directions. Actually, we found it most convenient to move the cursor by pressing the indentations in the pad rather than using the joystick at all.
The feel of the keyboard was as good as could be expected from the Chiclet-style keys. With each keypress, an audible keyclick sound is produced in the TV speaker to aid in accurate typing. This can be turned on or off with the commands CLICK ON OR CLICK OFF.
The SV-328 differs from the SV-318 in that it has a full-stroke keyboard with 86 keys. In addition to the keys on the SV-318, the SV-328 has a numeric keypad and arithmetic function keys to the right of the main keyboard, and the cursor control pad is replaced by four directional keys. The keyboard has an excellent tactile feel, and we had no need to leave the keyclick sound on. Extended Microsoft Basic
The version of Microsoft Basic in the SV computers is one of the richest we have ever seen. As mentioned earlier, all variables are automatically double precision unless specified otherwise in your program. This yield 16.8 decimal digits of accuracy which beats hands down any computer that we have tested with the exception of the calculator-like TI CC-40.
The computer has four types of variables: double precision, single precision, integer, and string. A variable type can be declared at the beginning of the program (DEFSNG, DEFINT, etc.) or by means of a suffix attached to the variable name (I%, B!, F#, A$).
There are 26 Basic commands. These include the usual NEW, RUN, SAVE, and the like, but we found a number of unusual commands as well.
KEY LIST lists the contents of the programmable function keys. MERGE brings a second program into memory and merges it with the one already there; if there are duplicate line numbers, the second program takes precedence.
MOTOR ON or OFF turns the cassette motor on or off while SOUND ON or OFF turns the cassette audio track on or off. SWITCH causes the computer to use a different memory bank. WIDTH sets the width of the screen display and TRON and TROFF turn the trace function on and off.
An extended list of 29 Basic statements includes BEEP and SOUND (R,B) which puts a sound byte, B, into one of the three sound registers, R. Control of the three sound channels is extensive and includes pitch (over eight octaves), amplitude, envelope period, envelope shape, and rhythm. In addition, there is a noise generator. To take full advantage of this sound capability, the SV computers include a Music Macro Language with 11 additional commands.
Other extended Basic statements include SWAP (exchanges the value of two variables), WAIT (suspends program execution to read an input port), OUT (puts a byte to an output port), DEF USR (defines an entry address for a machine language subroutine), and ERASE (releases space used by a variable array).
The Basic operators include the expected arithmetic and Boolean operations. In addition, we find MOD (integer modulus), XOR (exclusive OR), EQV (equivalence), and IMP (implication). The arithmetic functions are what would be expected; however, Spectra Video has thoughtfully provided in the User's Manual a table of 20 inverse and hyperbolic functions not directly implemented on the computer, showing the formula to calculate each one.
Again, the string functions are more or less as expected with the addition of HEX$ and OCT$ (converts numbers to hexadeciman ana octal strings), and STRING$ (L,E) which returns a string of L length with the numeric value specified by expression E.
The I/O and interrupt control functions and commands are facinating and allow amazing control of printers, terminals, joysticks, and other I/O devices. The SV computers have a built-in timer which can be accessed from Basic programs to perform all kinds of tricks. We were especially interested in the statement ON SPRITE GOSUB which causes the program to jump to an address when it detects a collision between two sprites.
Sprites are little graphics critters which can consist of up to 32 bytes which define colors and pixels on the screen (rockets, tanks, people, or any moving object). A program can use up to 32 sprites, many more than are available in other comparably priced computers. Unfortunately, neither the User's Guide nor the Quick Reference Guide included with the computer describes how to use sprites in a program. (Creative Computing had a multi-part tutorial on the use of sprites about a year ago.)
In addition to the various sprite commands, the SV computers have many other graphics statements which make graphics programming a real joy. These include CIRCLE, LINE, GET, POINT, PSET, VPEEK and VPOKE (peek and poke to video screen locations), and DRAW. This last command is used to draw on the screen with a special graphics macro language which has 14 additional commands. On-Screen Editing
More and more computers are being produced today with on-screen editing to replace the older systems which required an entire statement to be retyped or a special editing function to be invoked. With on-screen editing, you simply move the cursor to the place requiring a change, type the change, press RETURN, and presto, the change is made. Good on-screen systems include insert and delete keys, and allow the duplication of statements by simply typing a new line number over the old one; the SV computers have these features.
In addition, the SV computers have several other editing and cursor movement functions which are invoked by pressing the CONTROL key in combination with a letter. Some of these functions include backspace-and-delete, cursor to end of line, truncate line (a real joy!), and clear logical line.
The only "missing" editing command that we would like to have seen is Line Insert; however, the only low cost computer on which we have found this command is the Panasonic JR-200. Graphics Display
As mentioned earlier, the SV computers can drive either a color monitor or a TV set with an RF signal. Naturally the image on a monitor is better, but the computer produces a surprisingly good image on a TV set. Up to 16 colors can be produced simultaneously, although some of them tend to appear very similar. On the other hand, it is rare to want 16 completely different colors on the screen at one time.
The default color for text is a highly legible white on blue, although by means of the color command you can set this to anything you desire.
Normal text reoslution is 40 characters by 24 lines. In Basic, the bottom line is reserved for the function key definitions. Obviously, we thought, there must be a way to turn off this bottom line, but we couldn't find it except n the graphics modes.
There are two graphics modes, low- and high-resolution, appropriately enough. High-resolution provides 256 x 192 pixels; low-resolution has 64 x 48 boxes. In addition, you can use the graphics characters in text mode (40 x 24). While this sounds practically useless, bear in mind that the 52 graphics characters effectively divide each box into four; thus the usable resolution is more like 80 x 48. Program and Data Storage
SpectraVideo offers both a cassette recorder and floppy disk drive for the SV computers. We had the SV-903 cassette recorder for our evaluation. Unlike other computers, the SV machines cannot use just any cassette recorders. While it might be possible to hook one up, we recommend that you use the SV-903 which is designed for use the computer.
The recorder comes with a single cable which carries power, input and output signals, and control signals to the motor and audio speaker. This is a stereo recorder with programs and data on Channel 1 and audio, if desired, on Channel 2. The recorder has a built-in microphone so you can add your own voice support with your programs.
Digital information is stored at 1800 baud--an in-between speed these days. A 16K program takes a bit over a minute to load.
The SV-902 floppy disk drive is a compact unit which uses single sided, double density disks. The storage capacity is 163.8K per disk. According to SpectraVideo, with the disk drive, the computer is compatible with CP/M software. Naturally, you can't go to the store and buy CP/M disks that will run directly; however, this compatibility opens up the possibility of easy conversion of the huge CP/M software library from both the public domain and commercial vendors.
All these peripherals, as well as moderns, printers, and expansion memory, are plugged into the SV computers using either a single slot expansion unit or a motherboard expander with seven plug-in slots. Both of these expanders plug into the back of the computer and receive their power from the computer itself. Printer
SpectraVideo offers a printer, model SV-901, which is an 80-column, dot matrix unit that operates at 50 characters per second. This popular printer, made by Seikosha, is also sold by several other computer manufacturers as well as by Leading Edge, who call it the Banana.
The SV-901 printer will produce both text and graphics output, but alas, there are not descenders on the g, j, p, q, and y.
However, the printer interface will drive any printer with a Centronics parallel interface. Initially, we were unsuccessful in getting any printed output from our SV-328 on any printers here. A call to SpectraVideo revealed that Jumpers 1 and 2 on the printer interface card must be connected for most printers other than the Seikosha unit. this involves taking three screws out of the interface box and soldering two quarter-inch jumpers near the center of the PC board. SpectraVideo tells us that interfaces will be available for both kinds of printer; purchasing the right one is, of course, a better solution than soldering jumpers. Documentation
If there is a weakness in the SpectraVideo line, it is in documentation. The computer comes with a 136-page User's Manual and 22-page Quick Reference Guide. Both are punched for a 6" x 9" three-ring binder (included), but the spiral bound User's Guide is better used wihtout the binder.
The User's Manual takes a very different approach to teaching Basic than we have seen before. In particular, it starts with graphics and shows how you can use the computer to design simple pictures and draw them on the screen. This is an excellent approach and builds up interest quickly among new users.
Unfortunately, it doesn't go far enough. While it deals with all the standard Basic and graphics commands, it doesn't discuss any of the nifty extended features of the SV computers. Nowhere are we told how to use sprites. The amazing sound capabilities of the machine are covered in only the most cursory way.
The Quick Reference Guide has a short description of most of the Basic statements and commands and will be the document of choice for the skilled programmer; however, it too fails to describe the commands in sufficient detail to allow programs to be written without a great deal of experimentation. Indeed, after an afternoon of experimentation, I had more pages of notes than there were pages in the Quick Reference Guide.
However, it is our expectation that the SpectraVideo computers will achieve a strong market position and publishers will leap into the documentation void with enthusiasm. We are sure that authors will be eager to tell the world how to get the most out of a machine with these capabilities. Software and Support
SpectraVideo is no newcomer to the personal computer market, even though this is their first computer. They have been successfully marketing several excellent games and a joystick for the Atari VCS for some time. At CES, we were amazed at the lineup of software they had running on these computers, the prototypes of which are barely six months old.
SpectraVideo had a spreadsheet package, MultiPlan, MultiTool-Filer, home accounting programs, a word processing package, five utility packages, 15 or so educational programs, and scores of games. Moreover, they have announced an attachment which allows Coleco-Vision games to be played directly on the SV computers.
While SpectraVideo does not seen to be encouraging third party software manufacturers to develop software for the computers, they have not ruled it out either.
As far as service goes, at this point, it is a big unknown. Obviously, mass market outlets are not in a position to offer service other than exchanging the unit outright, hence, this will probably be the approach for service under the initial 90-day warranty.
Beyond that period, SpectraVideo tells us that they have an agreement with Carterfone to provide nationwide service through the Carterfone service organization. This seems like a good approach since Carterfone is a well-established, professional organization with electronic servicing experience. In Summary
The SpectraVideo SV-318 and SV-328 computers offer an incredible array of features at very attractive prices. The extended Microsoft Basic language has outstanding graphics, sound, and I/O capability. The keyboard on the SV-318 is among the best of the Chiclet-style untis whiel the full-stroke keyboard on the SV-328 is outstanding compared to any other. The on-screen editing is a joy, and the "extra" function keys make programming fast and easy.
The full array of peripherals means you will not quickly outgrow the system. The CP/M capability with the disk drive opens up a potentially huge library of software that augments the impressive lineup already announced by SpectraVideo.
The one glaring weakness in an otherwise outstanding offering is that the documentation just doesn't provide the information needed to exploit the advanced capabilities of the computer. Nevertheless, at the suggested retail price of $299 for the Basic SV-318, we agree with SpectraVideo, that this is a "computer system you'll grow into, not out of."
Products: SpectraVideo SV-318 (computer)
Spectravideo SV-328 (computer)