Problem: Printer Control Codes

[sebugg@presby.edu (Stephen Buggie)]

5-24-94

        PRINTER CONTROL CODES PROBLEM: COMMODORE 6400 HIGH SPEED DAISY WHEEL
        ====================================================================


One of my favorite printers is the first I acquired:  Commodore #6400.  This
is a mid-1980's vintage high speed (40 cps) wide carriage daisy wheel letter-
quality printer.  It is a "Diablo 630 clone," using the Diablo 630 printer
control codes, ribbons, and type wheels.  Like other impact printers, it is
noisy but makes great quality type.  It is made by C. Itoh Co. which also
makes the Apple Imagewriter II.  Its large (31 lbs) and well made.

Recently I obtained at a give-away price an identical Commodore 6400 printer.
This printer is identical in every respect.  Even its serial number (709069)
is within 3000 units of the other printer.

I use the printers with an Apple IIe fitted with a Grappler Plus parallel
interface card and a parallel-parallel Quandram Microfazer 64K external
printer
buffer.  Bank Street Writer Plus is the word processor software.

The new printer works great EXCEPT for two faults:  I cannot activate either
the UNDERLINE or SHADOW (BOLD) printer codes!  Thus I seek advice now.

These are the printer codes from the manual.  These codes work perfectly
with my "original" Commodore 6400, but not with the recently acquired one:

                   FUNCTION           CONTROL CODE
                   ===============================

                   underline-on       (27)E
                   underline-off      (27)R

                   shadow-on          (27)W
                   shadow-off         (27)&


The newer printer does not respond to the codes to activate underlining or
shadowing (bold) functions.  But it DOES respond to other printer control
codes (character pitch spacing, vertical line spacing, carriage settle,
subscript, superscript, etc.)  This the problem is NOT a general fault of
failing to recognize printer codes; but a specific problem of not responding
to these two important functions.

The printer's previous owner wrote that the printer did respond to underlining
but he was not able to activate the shadow function.

So, what should I check next?  It is the identical printer to my other one,
used with identical hardware and word processing software.

I realize that there are many possible elements that can be checked.  I hope
that expert readers will suggest a PRIORITY RANKING of what components should
be checked first.......last, ranked in terms of the likely causes of this
problem.

E-mail replies appreciated.  If a solution is achieved, then I will post a
follow-up message giving its details for the interest of readers.

Stephen Buggie        e-mail:    sebugg@presby.edu



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 ** Stephen Buggie  Psych Dept  Presbyterian College   Clinton SC 29325 **
 ** sebugg@presby.edu                 voice: (803) 833-8337 or 833-1632 **
 **       Douglas DC-3.....Volkswagen Beetle.....Apple II forever       **
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