[sane-devel] dye-sub Canon ES20, ES40 help

[Gernot Hassenpflug]

Dear Michael Mraka,
This is Gernot Hassenpflug, I was told you are the person to speak to
about dye-sub printers. I hope that is OK.
I have been looking at the code in print-olympus.c and am a bit confused by:-

a) whether the ES20 support is correct, and
b) how to make changes to support the ES40

What I have done is looked at the first 20 or so bytes of printjobs
for both these printers. I did not loko further yet. So far, the first
20 bytes show some significant differences between the 2 printers, but
on the other hand, I cannot see there any specification of "edgeless"
or "non-edgeless", or "portrait" vs "landscape" differences. Anyway,
here the comparison, mostly for the first 5 bytes (others are the same
except where noted), in hexadecimal notation.

Color:

postcard:
ES20: 40 00 01 00 02
ES40: 40 00 00 00 00

CP_L: (89mm by mm)
ES20: 40 00 02 00 02
ES40: 40 00 01 00 00

Card: (54mm by mm)
ES20: 20 00 03 00 02  and also 12th byte: 01
ES40: 40 00 02 00 00  and also 12th byte: 00

Black/white (postcard only):

ES20: same as color, but 8th byte: 01
ES40: same as color, but 4th byte: 01

Conclusions:

a) paper type numbering is 0-based for ES20, but 1-based for ES40
b) ES20 5th byte is always 02, while for ES40 it is always 00
c) for black/white, ES20 sets 8th byte to 01, while ES40 sets 4th byte to 01.

I am not sure of other differences yet, if there are any utilities
available to examine the print-jobs more easily please let me know.
Best regards,
Gernot Hassenpflug