NEC SPINWRITER: red-black control codes for ribbon

[sebugg@presby.edu (Stephen Buggie)]

sebugg@presby.edu                                          Sept. 7, 1993

    NEC SPINWRITER MODEL 7715:  NEED COLORED RIBBON PRINTER CONTROL CODES
    =====================================================================

My favorite printer is my NEC "Spinwriter" model 7715, a high-speed (55cps)
letter-quality wide-carriage serial printer, made in 1981.  It produces
daisy-wheel quality text using a unique plastic "thimble" spinning type
element.  The printer was obtained from my college's admissions office at
a give-away price when the office upgraded to a silent laser printer.
I am very happy with the performance of the NEC Spinwriter, although I
have not yet succeeded in getting my serial printer buffer (Quadram serial
Microfazer) to work with it.

The NEC Spinwriter uses either multistrike film ribbons or nylon cloth ribbons.
Recently I have had the chance to buy some two-color (red/black) nylon ribbons
for it.  I tested a sample ribbon which partially worked;  I ask this group for
advice in setting the printer control codes correctly so that the both colors
on these ribbons will be usable.

I have the manual for the Spinwriter and it presents the two control codes for
red and black printing.   Unfortunately, while these codes shift the ribbon
position, the resulting shifts have not yet enabled me to use the black portion
of the two-color ribbon.  The table below summarizes what was expected and what
the printer actually did:


                            DEFAULT             ESC A            ESC B
-----------------------------------------------------------------------------
According to manual:     black printing     red printing     black printing

Printer's behavior:       red printing      red printing    impact w/o ribbon


When I toggled back and forth between ESC A and ESC B, the printer responded
by either turning on or off the red ribbon.  But I have not yet succeeded in
getting the black portion of the two-color ribbon to print!  The printer does
respond to the control code toggling, but by lifting the ribbon out of the
way instead of placing the black portion in the striking field.  The black
ribbon portion does seem to have sufficient ink.  Also, when I substituted
one of my freshly re-inked all-black ribbons, the same behavior occured in
response to the ESC B command.

All other printer control commands (e.g., underline, bold, subscript, super-
script, pitch variations) work accurately according to the manual.

QUESTION: What code should I try to activate the black portion of the two-
color ribbon?  I would like to get more of these spinwriter ribbons but have
limited use for ribbons which only print red.  Also, if this code problem
can be cracked, then I may be able to use the unused virgin portion of my
present all-black ribbons    B-)

Advice will be appreciated!   sebugg

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 ** Stephen Buggie, 410 Chestnut St., Clinton SC 29325    Apple IIe/IIc **
 ** sebugg@presby.edu                 voice: (803) 833-8337 or 833-1632 **
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