The Comprint interface, with its built-in software, gives Commodore owners the chance to hook up easily to an Epson-type printer, says Francis Jago

The Comprint package, which allows Commodore owners to plug in an Epson printer, is something of a novelty as it has the necessary software built-in.

The package consists of a circuit board which plugs into the same slot as an Epson expansion interface. The board is then screwed firmly into place and is ready for use. The software is on one 2764 8K EPROM, as in the BBC, and with the cable provided, it plugs in easily.

With the board installed, you must set the printer's dip switches, depending on whether you are using an RX, FX or MX printer. The controlling software uses the four printer operation commands - OPEN, CMD, PRINT and CLOSE, all followed by a logical file number. All data sent to the printer after one of these four commands is easily controlled by secondary addresses. These are numbers which set such features as lines per page and the definition of programmable characters.

One of the best features of the software is the complete control you have over formatting the printed output. This includes left and right justification, as well as the positioning of decimal points.

Another nice feature is the way the software provides complete emulation of a normal Commodore printer, such as the MPS 801 or 802. This means that the Epson can print all Commodore graphics and, using the screen dump from Simons Basic, produce higher quality dumps than from a normal Commodore printer (the print quality of which is not as precise as an Epson).

It is impressively easy to produce all the available print types, such as enhanced and programmable characters, in any combination. The software uses CHR$(N) to send commands to the printer, with n as a number varying from 1 to 254.

To define a character on the printer you should lay out an 8 x 8 matrix, or 11 x 9 if using an FX80. Next, adding up the binary value for the dots in each column, these are used as data in the program to define the character. Being able to put multiple programmable characters on one line makes detailed drawings on a small scale possible.

When using the printer with a word processor, the 2K buffer speeds up the process appreciably. Although the special characters including in the software are specifically limited to maintain compatibility with the usual Commodore printers, they are still comprehensive enough to include facilities, such as paging and carriage returns, without line feeds.

The manual supplied with the Comprint contains all the information necessary to program any Epson printer. It produces a finished article better than is usually associated with a Commodore machine.

Overall, the Comprint interface, with its built-in high quality software, presents excellent value for money, and a worthy purchase for any Commodore 64 or Vic 20 owner who doesn't want to buy a Commodore printer. The software is well-written, concise, and takes up no basic RAM from the computer; in fact, it beats its rivals on several counts.

Features 5/5
Documentation 4/5
Performance 4/5
Overall Value 5/5