[Coco] Printing on a Coco with modern printers.

[Frank Swygert]

Date: Thu, 09 Jan 2014 18:24:07 -0500
From: Al Hartman<alhartman6 at optonline.net>

I don't agree that a Coco or a Coco 3 isn't powerful enough to print to
modern printers. It might assemble a page more slowly than a modern
computer, and might not be able to rasterize a full page at high resolution
due to memory constraints, but there's no reason a Coco can't print text or
graphics at usual CoCo resolutions to a modern printer.

Cocomax, CGDP, ColorMax and other programs printed hi-res (for a Coco) text
and graphics to a wide range of printers. There's no reason that they could
not do so today.

All that's needed are drivers.

===================================================

The printers the CoCo and all it's programs were designed for had built-in character sets to work with. That's why they printed rather fast. Now you are correct as far as CoCoMax and such -- they printed a graphics screen and didn't use the built-in character set. You would need a complete program that would turn an ASCII file into a rasterized graphics file, which wouldn't be too difficult, and send that to the printer. The program would have to know how to communicate with the printer. Practically all modern printers use PCL (Printer Command Language), developed by HP. The CoCo should be capable of producing PCL1 output, which all modern printers can still interpret. It would require more than just a driver on the CoCo -- I'm not sure OS-9 could even handle PCL in a typical (for OS-9) driver. But as a program with printer output piped to it.... The program could have a standard character set defined in it similar to the old dot matrix printers. I think that's how PCL1 worked anyway, but you'd have the option of defining the character set. It would be hard to use multiple character sets as CoCoMax did, but a single character set defined in the driver shouldn't be too slow...

Of course there are still some dot matrix printers out there, mainly used for industrial printing such as multi part forms. They are available in the $150-200 range and will work with a serial to parallel converter. I'd opt for an Okidata 1120 9-pin -- $209 from Newegg. It has an RS-232 port so no converter needed. Okidata is the only new production printer that still has a serial port, apparently. A new converter can still be had for a bit over $100 (http://www.bb-elec.com/Products/Serial-Connectivity/Serial-Converters/Serial-to-Parallel-Converter.aspx), but the lowest cost printer (new) is a Lexmark forms printer for $170 (it is 24 pin though). That brings a new CoCo ready printer up to around $300 -- and you'll need to make a cable. You can find converters on e-bay and Amazon used. One good one is the Aten SXP-320A. It's been discontinued, but there is one on e-bay now (used) for $29, and on Amazon for $99 new (old stock). Don't know when they were discontinued, but now would be a good time to get one!

Of course we have some soldering iron handy people on here -- make your own with a microcontroller!
http://www.drdobbs.com/embedded-systems/designing-a-parallel-to-serial-port-adap/223100564?pgno=1

A Raspberry Pi could be programmed to do the same thing, and no soldering if you are a good programmer. Might be cheaper than using a micro controller...

The point is the converter would still need an old fashion dot matrix printer with built-in character set. An RPi should be able to handle a modern PCL based USB printer and convert serial input directly to a pre-selected character set, or use Eposn emulation for full graphics compatibility with the CoCo. Printing directly with the CoCo would be slow, most users of CoCoMax can tell you that! Resolution leaves a bit to be desired too, even from a 24 pin printer. I've used CoCoMax -- the output is okay for what it is, but not that great.

-- 
Frank Swygert
Editor - American Motors Cars Magazine
www.amc-mag.com