On Jan 31, 2010, at 1:36 PM, Tony Duell wrote: Okidata does too, as do many other manufacturers. Even the venerable Okidata Microline 320 is available with a USB interface. They're almost always used for multi-part forms and individual print jobs which require less than a whole page of output, like receipt printers. I'm doing some consulting work for a local retail chain that uses USB-connected Oki 320s as receipt printers for single- part pin-fed forms. This is preferable to a laser printer because they get three to a page, significantly reducing their paper usage. Dedicated thermal receipt printers are nice, but from what I've heard they're not as reliable as dot-matrix impact printers in the field. That seems odd to me, but I guess the heating elements dying does make some sense. -Dave -- Dave McGuire Port Charlotte, FL

Dave McGuire wrote: There's one major issue with direct thermal: ink fade. Basically the printing fades over time. Some retailers love this, because after about 8 months the receipt is basically blank -- "Sir, we'd be happy to accept that under the 12-month guarantee, but we need a receipt -- not a blank strip of paper." For bonus points: heat and light make it fade quicker. Leave a thermal-print receipt on a windowsill on the 1st of the month and it'll be blank by the end of the month. Leave it on or near a radiator and it'll go completely black within a few minutes. There are also significant chemical compatibility issues. Most notably, applying a strip of Sellotape to a thermal-printed slip/receipt causes the ink to fade over a matter of hours (or in some cases minutes). This is great fun in photo labs -- you have an order slip with the order number on it, which the customer takes to the counter to pay. That's then taped to an order docket, which is given to the lab guy to print. Catch: tape erases the printing on the order slip, so you by the time the prints are done, you've got a docket and no matching order number. (Process C-41 bleach-fix fumes just serve to speed up the fading process!) Such fun. -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

Tony Duell wrote: I thought the fading issue was quite commonly realised, esp. if you're the type that hangs on to receipts. On the other hand, I have dozens of printouts from high school in 1976, from the printer for a HP9830 computer/calculator, taped to sheets and bound in a folder, all of which are completely legible, very slight fading, except for some corners under 3M tape which have faded completely.

On 1/31/2010 8:38 PM, Chuck Guzis wrote: "all but unreadable" sounds like they are faint and almost discernible. If that's the case, scanning them and then making drastic adjustments to contrast should render them readable. -- Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/ Help our electronic games project: http://www.mobygames.com/ Or check out some trippy MindCandy at http://www.mindcandydvd.com/ A child borne of the home computer wars: http://trixter.wordpress.com/

On 31 Jan 2010 at 19:58, Brent Hilpert wrote: How are your old blue-line copies doing? I found a couple in one of my desk drawers and it took quite a bit of time to even figure out what they were, they had faded so much. D size--too big to scan. --Chuck

It's certainly well-known among the users of old HP calculators which have thermal printers. But few opther people seem to realise it. I assume this was the HP9866 thermal prionter. THe one that stacks on top of the 9830 and looks like part of the main machine. I mention that becuase while the 9830 has a built-in interface for that 9866 printer, you could link all sorts of other printers to it (there was certainly a daisywheel, the HP9871). The built-in interface was similar in concept to a Cnetronics port (7 parallel data lines, strobe, acknowledge IIRC), and could fairly easily be hacked to something else. Assuming it was the 9866 thermal printer, I guess whether the printout fades or not depends more on the peper than the printer itself. YOu can uuse normal thermal fax paper in this printer (I assume you can still buy that), but I guess you were using the genuine HP stuff. -tony

In Brazil, this is very common, although we are moving for a digital invoice. And it is hellish complicated and expensive, but orders of our nice govnmt.