Issue 15, June 1985 - Thermal Printers
| H O T H E A D S If you're not that flush, but you need a printer, stay cool and go thermal. Peter Green comes in from the cold to consider the hottest ones around. |
dump, so duplicating the COPY command. Although you'll have to bone up on the graphics modes before you get to grips with them fully (especially since most Epson-compatibles are Japanese, with manuals written in Janglish!), they do allow you to draw dot graphics of any kind, unrestricted by the Spectrum screen size or resolution. And as they all use roll paper, you could write a program that printed a frieze type of picture.NO LIMIT?Bear in mind if you're considering thermals that, with one exception, none of them can handle A4 width paper, or even cut sheets. Using roll paper means that the top and bottom of your printouts have ragged edges where you've torn them off. Still, that's OK if you only want the printer for listings - or if you're happy sending out letters that look like supermarket checkout receipts.You'll also need another spare mains socket. All but one of these printers require an external power supply, of the small transformer PSU type. Two of them can run off batteries, but they eat them and if you don't use re-chargeables, your running costs will be unbelievable. WHAT PRINTER?Before choosing one of these printers, you'll have to decide exactly what you're going to do with it. If you're looking for a straight replacement for the ZX Printer, then the Floyd 40 is your best bet. Unlike the Alphacom it does a lot of clever tricks besides duplicating a Sinclair printout.However, if you're likely to be writing letters and so forth, you'll need to look up-market a bit. There, the Epson P-40 equals the Brother HR-5 on features, but for the extra fifty quid, the HR-5 lets you use cut A4 sheets and offers the back-up of ink ribbon if you run out of thermal paper. Remember though, that you'll need an extra interface for both of them. | |||||||||||||||||||||||||||||||||||||||||||||||||||
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The Sinclair ZX Printer was unique - for its size and price, it was quite a remarkable technical achievement. Still, it did leave something to be desired. All those sweaty paw prints, left all over the silver listing paper. And the print quality would strain the definition of the word adequate, as well as your eyes. Program listings on the stuff cause harassed editors to tear their hair out (or at least that's Kevin's excuse!). One solution has been to find a way of linking 'real' printers, like the large dot matrix ones, to your Spectrum. For that you need a commercial interface, or you could have a crack at knocking up one yourself. (Of course, you'll need a copy of YS issue 6 for that. Ed). This works, but your Speccy is now dwarfed by a huge printer - a bit of a shame when Uncle Clive has gone to so much trouble to keep it all small. And it causes even more problems if you've got to squeeze your complete computer set- up into the confines of a cramped living room - worst of all it means shelling out between two and three times as much for the printer as you paid for your Speccy. That's good enough reason for me to look seriously at thermal printers. ANYTHING YOU CAN DO ...So, what can thermal printers do that dot matrix or daisywheel can't? Well, nothing really - except save you a lot of space and some cash. Most of them are quite tiny, and the good news is that they're all comparable in price to a Spectrum.Thermal printers don't need linked ribbon because they use special paper impregnated with a heat-sensitive ink. The print head is still 'dot-matrix' but the |
dots are small wires that can be independently heated. The heat makes the ink visible in the correct dot patterns to display characters. Take into account that the saving you'll make on ribbons is
offset slightly by the higher cost of the special paper. It's only got to brush its heating elements over the surface, as the print head doesn't have to strike the paper to form an image. Also, thermal printers ought to be much quieter than dot matrix ones to make its mark. Not so though, I'm afraid - to bring the price down the manufacturers often use fairly cheap electric motors to feed the paper and scan the print head, so you get a different sort of noise, but it's not quieter. It's no coincidence that the least noisy of the printers I tested was also the most expensive. If you plump for one of the most basic of the thermal printers, you won't need an interface. They are designed as plug- in replacements and work directly from the Spectrum bus. The others have standard RS-232C or Centronics ports, so you need a printer interface as well - take this into account when you're considering your budget. For the extra though, you'll get many of the features of the big machines, including emphasised, condensed and enlarged fonts, variable line spacing, international character sets and bit image graphics. IN THE PICTUREBit image graphics means you have direct control over the heating elements in the print head. So, you can print any pattern of dots onto the paper. Interfaces such as the ZX Lprint contain the software that uses this facility to perform a screen | |||||||||||||||||||||||||||||||||||||||||||||||||||
HOT STUFF
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ALPHACOM 32 Dean Electronics, xxxxxxxx xxxx, xxxxxxxx xxxx, xxxxx, xxxxx. When it comes down to performance, the Alphacom 32 is simply a souped-up ZX Printer. It will LPRINT, LLIST and COPY in exactly the same 32-column format and nothing else. It won't recognize any of the standard Epson control characters which alter the print width, font style or anything else. And you won't get the graphics commands in any other form than the COPY mode. It even prints a question mark if you send it a line feed code! For my money, this makes it the least useful of the four printers. I tested the blue thermal paper (though you can get black) and found it easier to read than a ZX printout, but the print quality was about the same. The printer also kicked up a bit of a racket - there was a constant grinding of the powerful, geared motor throughout the printing cycle. The machine has a similar footprint to the Spectrum. There's a through connector for other peripherals but the thick connecting cable puts pressure on the power input jack so you can't tell whether it's on or not - it uses non-latching membrane one-off switches and there's no LED indication. The plus is that it's a plug-in-and-go printer, so no software setting-up is required. | FLOYD 40 Shive Instruments Ltd, nnn xxxxxxx xxxx, xxxxxxxxxxx, xxxxxx n. Nice software, shame about the case! This is the tattiest looking of the four, but it's got some pretty nice facilities. I had to repair the thing before I could use it, as the printhead/motor mechanism is secured internally by three drops of glue - not such a great idea for goods entrusted to our postal service! To be fair though it was a pre-production model. This is another plug-in ZX Printer replacement with a through connector, but this one draws its power from the Sinclair supply. It offers several formatting modes which use embedded control codes flagged by !. Automatic word-wrapping is performed on printed text to make your paragraphs neat. The word-wrap also takes into account that characters may be printed double-width. You can also have double height and inverse characters or any combination of the three that takes your fancy. If you're printing out listings, you'll get them with right-justified line numbers, and everything else is indented and word-wrapped. All of which makes for very readable listings. Graphics mode prints everything just like the ZX Printer. You'll have to get used to the slight inconvenience of the embedded codes, but the results are worth it. | EPSON P-40 Epson UK Ltd, xxxxxxx xxxxx, nnn xxxx xxxx, xxxxxxx, xxxxxxxxx xxn nxx. This is a smart, simply-styled pocket-size printer offering many of the facilities of its bigger brothers in the Epson dot-matrix range. Enlarged, emphasised, condensed and normal characters are software-selectable using the standard control codes. You're also offered Epson bit-image graphics and several international fonts. This is certainly the neatest of the four printers. It's fractionally smaller than a Spectrum, and I reckon you could fit about eight P-40s into one of the standard 80-column dot-matrix printer. The P-40 can print 40 or 80 column text on its 110 mm (4") wide paper roll. Easily accessible DIL switches let you select things like default column size, auto line feed, and RS-232C data format and baud rate if you're using that interface. In fact these simply poke through the back of the case so you don't need a screwdriver. For it's size, the P-40 makes a bit of a din. It runs off an internal NiCad battery. If you go for this printer, I'd recommend getting the Centronics version (plus a suitable interface like the ZX Lprint III) rather than the RS-232C version. Epson use non-standard RS-232C connectors to save space and we had great difficulty in connecting up the equipment. | BROTHER HR-5 xxxxxx xxxxxx, xxxxxx xxxxxx, xxxxxxxxx, xxxxxxxxxx xnn nxx. This is the largest of the four printers but it's also the most versatile. For starters you get the choice of using either thermal or ordinary paper, and there's no problem with fitting in the ribbon cartridge. The HR-5 senses automatically which type of printing's required. Second, it's the only one of the printers to accept A4 cut sheets, so it's ideal for letters and the like. It offers all the printing options of the Epson, plus its own internal graphics character set. The actual printing is performed fairly quietly, and with the thermal paper, I obtained a very contrasty, high-quality printout. Beware however - the thermal paper only works one way round, and the two sides are almost identical. Print quality is just as good if you're using the ribbon on ordinary paper, though because there's no striking action, smooth copier-type paper is best. You can also use roll paper with the clip-on roll holder that comes as an accessory. Battery operating is possible, but at 1 amp they peg out pretty quickly - I fitted a new set and got a low battery warning after printing one page! So use the mains adapter. I'd certainly recommend this one as the top-of-the- range choice. |