Classic Epson printer emulators

[Tony Duell]

> 
> Dave McGuire wrote:
> >   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.
> 
> There's one major issue with direct thermal: ink fade. Basically the 

Indeed. Many older (HP) calculators used thermal paper. It'sa good idea 
to make photocopies (or I guess scans these days) of any printouts you 
want to keep. 

It's not generally realsied that themral printouts fade with time. I was 
chatting to somebody from a major museum and he didn't realise the 
historically-significant calculator printouts needed to be copied _NOW_.

> 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.

Needless to say a soldering iron works just as well. I've been known to 
use one to check if the paper is still thermally sensitive, and to see 
which is the sensitive side.

> There are also significant chemical compatibility issues. Most notably, 

Propan-2-ol will darken most thermal paper, as I fopudn out the hard way 
when clening a bit of hardware with said solvent and some othe spray 
landed on some printouts from my LogicDart (it uses the HP82440 IR 
thermal printer)..

> applying a strip of Sellotape to a thermal-printed slip/receipt causes 

Pehaps I've been lucky,but I've not had any prolems sticking down HP 
calculator printouts with 3M 'magic tape' onto a piece of plain paper to 
make them easier to copy.

[...]

-tony