[comp.periphs.printers] Print Wheels

sichermn@beach.csulb.edu (Jeff Sicherman) (06/09/91)

  Please excuse the introduction of prehistoric technology into this group :-)

  Has anyone ever seen a printwheel (for a Diablo 630 preferrably) with just
dots and/or bars arranged in various patterns so the wheel could be used to
print rasterized graphics. Failing that, are there any with the upper half
(or some portion thereof) of the full IBM PC characater set (128-255).

  Yes, I know this sounds silly; don't ask.

wb9omc@dynamo.ecn.purdue.edu (Duane P Mantick) (06/22/91)

sichermn@beach.csulb.edu (Jeff Sicherman) writes:

>  Please excuse the introduction of prehistoric technology into this group :-)
	
	As a *former* member of the "I have done service on Diablos
and learned to love/hate them" club, I will forgive your divergence
into ancient history.   :-)

>  Has anyone ever seen a printwheel (for a Diablo 630 preferrably) with just
>dots and/or bars arranged in various patterns so the wheel could be used to
>print rasterized graphics. Failing that, are there any with the upper half
>(or some portion thereof) of the full IBM PC characater set (128-255).

	Never seen a dots/bars wheel.  Most Diablos from 1640/1650 and
onward through 630 that *I* ever saw could do some limited graphics
by using the command that decreases the VMI and HMI (Vertical Motion
Index and Horizontal Motion Index) to some very minute fraction
of an inch.  And you know, the damn thing actually worked!  But lordy,
it was SOOOOO slow.  It generally amounted to using the 'period'
character to slowly strike a fine line; if you had written a program
you could thus mix this mode with using the | and _ or - or = and some
others to make graphs.  You could conceivably also use normal text to
print titles and so forth onto the graph, assuming you *didn't* want
them to print sideways.....

	The commands are like this:

HMI = ESC US (n)    where US is a CTRL-_ and n is an ASCII chr. with
			a decimal value from 0 to 125
VMI = ESC RS (n)    where RS is a CTRL-^ etc etc.

Note that the spacing works in 1/120 inch increments for HMI and 1/48
inch increments for VMI.

If you need further info. for the Diablo 630, RTFM...  :-)

NOW - as far as raster graphics go, OUCH!!!  I never heard of anybody
being masochistic enough to want to use a Diablo for Raster stuff.

>  Yes, I know this sounds silly; don't ask.

	It would almost be interesting to know....  :-)

OH, BTW, you might be able to locate wheels for IBM stuff.  I seem
to recall that there might have been an IBM interface option for
Diablo printers but I don't know if it was for the 630 or if it
started later, maybe 635-ish.....OH yes, here it is.  I just 
dusted off a file of 630 stuff...

There was a beast called a Diablo 630ECS (which, as you might have
guessed, stood for Extended Character Set).  The feature chart marks
this as "ECS for IBM PC".  Here's the neat part...each petal of the 
print wheel had TWO different characters on it, one slightly skewed
to the other one.  Printers that were equipped with the ECS carriage
had a solenoid that could move part of the carriage to strike one
chr. set or the other and get double the number of characters out
of each wheel.  The next version of that, which was supposed to be
the Diablo 801F, had two hammers, one aimed at each of the two sets
to avoid mechanical shifting.  In theory, the 801F was spec'ed as
a 80 cps letter quality printer in 1985.  This was Diablo's attempt
to save the daisywheel printer from obsolescence.

	Here at Purdue we just send them to the junkpile and smile
at our Apple Laserwriter II NTX's....  :-)

	However, if YOUR 630 does not have the ECS carriage, I think
you are out of luck.

	IMHO, NEC had a much better approach to the IBM PC compatibility
problem with their 8850 Spinwriter.  The 8800 series Spinwriters
were a niffty little box that had a module you selected at purchase.
The 8850 happened to come with the IBM PC module that setup the 
interface and character junk automatically.  You bought the print
thimbles for IBM compatibility and you were ready to roll.

	Just to rub salt in your wounds, IMHO, there never was a
Diablo that could *touch* a 7700 series Spinwriter for quality
of construction and ease of service.  In fact, the NEC 8800's 
couldn't, either.

Disclaimer: I never worked for EITHER Diablo/Xerox or NEC. I just
worked ON their printers....  :-)

Good luck, and if I can fill your head with any other Diablo or NEC
Spinwriter trivia, let me know...  :-)

Duane Mantick
Purdue Engineering Computer Network
wb9omc@ea.ecn.purdue.edu