Epson HI-80; a versatile, accurate, four-color plotter at a surprisingly modest price. (evaluation) David H. Ahl.

The HI-80 plotter epitomizes the Epson tradition of offering well-designed, reliable products at a modest price. The HI-80 handles paper up to the European A4 size (slightly larger than U.S. letter size) and has a plotting area of up to 267mm x 192mm (10.5" x 7.6"). Up to four colors can be used on one plot. The plotter uses a standard parallel interface, thus eliminating the need to fool with RS-232 cables, DIP switches, and matching parameters.

The plotter is about the size of a dot matrix printer (16.3" x 10.8" x 3.1"). On each side a serrated metal paper roller and rubber wheel grip the paper and move it back and forth (along the long dimension) while the pen holder moves from right to left (along the short dimension). This mechanism leaves a barely noticeable perforation in the paper. The plotter works with either plain paper or film (for overhead projectors). Three types of pens are available, each in ten colors: the standard fiber tip (draws about the width of a Pilot Razor Point), ballpoint (for a finer line), and fiber tip with an oil-based ink (for drawing on film).

Repetitive accuracy of pen movement is specified to be better than 0.3mm for a single pen and 0.5mm for different pens. In our tests, actual accuracy was considerably better than these figures. According to Epson specifications, a fiber pen should draw 200 meters over its life (400m for ballpoint and oil-based fiber tip). We did not check these figures, but have no reason to doubt them.

The plotter has three modes of operation. Mode 0 is the normal plotter mode and uses 42 two-letter commands. Mode is a more basic plotter mode and uses 18 single-letter commands. Printer mode simulates a printer and has 38 commands for producing text in various typefaces and styles. It is possible to produce text in Modes 0 and 1 as well, although for extensive text on a chart, it is probably most sensible to do the chart in Mode 0 or 1 and add the text in printer mode.

In addition to the on-line modes, the HI-80 has a self-test mode which checks the control and mechanism functions and the drawing quality.

The plotter has only a few controls. An on/off switch is located on the right side, while touch sensitive switches for on/off line, pen up/down, pen cap on/off, and pen position are found on top. Three LED's indicate power on, on-line, and error condition. Unfortunately, once an error occurs, there is no way to recover from it short of turning the plotter off and back on. This makes program debugging somewhat tedious, particularly in the beginning when there are likely to be numerous errors.

A plotted point in either the x or y direction is equal to 0.01mm; thus there are 2670 points in the x direction and 1920 points in the y direction. These points may be located within a virtual plotting area ranging from -32768 to 32767 depending upon where you locate the origin. The plotter has no automatic scaling capability; all scaling must be done within the program.

All commands are sent to the plotter using the LPRINT statement. Commands in both plotter modes include the expected move and draw from an absolute point, move and draw relative to the last pen position, and go home. There are commands to draw axes, graph markers, and eight types of lines. Printing can be added to charts in various directions and sizes, pen number and speed specified, and the plotter buffer cleared.

Mode 0 has 24 additional commands for moving the pen to the origin, altering the drawing window in the virtual plot area, setting an enlargement factor (a crude way of scaling), drawing circles and arcs, drawing smooth curves between a series of points, and drawing arrows, grids, cross hatching, and pie segments. This mode offers a wider variety of text features than Mode 1; they include emphasized, slanted, vertical offset, and rotation. In all, the HI-80 has more commands available than any other plotter in this price range. One of the only commands missing is one to draw ellipses or ellipse segments, but this is rarely found on plotters costing under $2000.

The commands in the printer mode practically duplicate those of a full-featured dot matrix printer including normal type, italics, double-strike, enhanced (second stroke slightly offset from first), superscript, and subscript. Character height, width, and slant can be set as well as line spacing, margins, and tab stops. You would not, however, want to use the HI-80 in place of a printer; although the results are excellent, it is slower than the slowest dot matrix printer. Its printing capability should be reserved for charts and overhead projector transparencies.

We tried producing a variety of mathematical and business charts on the HI-80 and were very pleased with the results. The commands were easy to learn and, except for the annoyance of having to enclose every individual comma in parentheses, easy to use. (Houston Instruments' approach of letting a space represent a comma--with or without parentheses--makes entering and reading plotter code much easier.)

The fat 305-page manual is very thorough and even goes so far as to include an example of plotting a graph using SuperCalc (other spreadsheets would be similar). A minor nit is that line 150 of the Line Drawing Program on page 7-12 should use the COS function rather than the SIN function as printed; but that will be evident soon enough if you enter the program as written, because it won't work.

All in all, the Epson HI-80 is a remarkable performer at only $599. It boasts the most complete set of plotter commands in its price range, offers excellent accuracy, is easy to learn and use, and, if it is built like other Epson products, will have high reliability as well.

Products: Epson HI-80 (computer printer)