This is, essentially, InitPrinter. (Hear, AmigaOs source code public. (-;)). Everything else is up to the printer driver which takes this ANSI code and generates the printer-specific verson of it. This generate a bunch of CSI codes that are created both by the aRIS command (which is the nice name of this reset sequence), and the generic initialization of the printer that installs the page margins etc from the preferences.
a) It looks like the printer.device does its own Initprinter() when opened, then SYS:Tools/InitPrinter does Initprinter() and then before PRT: closes, it adds a form feed at the end. I think you might mean aRIN since if I send aRIS, I only get the PCL code of "*EE" (HP reset code). One question is why the Initprinter() does not issue aRIS at the beginning before the aRIN?
Another way to say this if that I can see aRIN when doing below and see the form feed at the end (using CMD). The "test" text sits inbetween.
echo >prt: "test" NOLINE
b) I'm actually seeing a form feed (CTRL-L) in text mode and in graphic mode. And if I do below with no CMD, a form feed happens on the ink jet printer and resume light blinks.
echo >par: CTRL-L NOLINE
c) If I do a PCL code of a single reset, the power LED starts blinking (according to the manual when LED blinks this means data is being received):
echo >par: "*EE" NOLINE
If I do a second "*EE", then it stops blinking. No clue why I get 2 different responses for the same code being sent.
And finally, if I do a:
echo >par: "*EEtest*EE" NOLINE
The text "test" gets printed and the 2nd reset ejects the paper without a form feed. No resume light blinks. Or alternatively,
echo >prt: "test" NOLINE
echo >par: "*EE" NOLINE ; turns off blinking by issue reset after form feed (0xC) from prior command.
It seems like the Pagestream driver when it issues a *EE (PCL reset) at the end, this essentially does a form feed and no resume light blinks.