28 Nov
2005
28 Nov
'05
12:03 a.m.
On 11/27/2005 at 6:19 PM ard at p850ug1.demon.co.uk wrote:
Well, I was prtty certain, but I don't have the
service manuals
immediately to hand. I would be very certain about the 12/7, and fairly
certain about the 700 (which is actually built on a Diablo 630 chassis
with totally different elecronics and a dot-matrix head).
I do remember the Diablos having enough moxie on the carriage drive motor
to do some very serious damage to your hand should you be unfortuante
enough to have it the way at the wrong time. The NEC Spinwriters, OTOH,
were pretty wimpy in that respect.
I think that's the reason for a lot of the Sanders
electronics (the 700
had 3 micropeocessors in it -- 2 Z8s and a Z80) - -to handle the
acceleration of the carriage motor and put the dots down at the right
time.
The Durango here is patterned after the Sanders in one respect--it uses a
fine wire dot-matrix printhead to do multipass character formation through
a film ribbon. The quality from a 9 wire printhead is very good. Includes
downloadable fonts, too--some over an inch tall. The brains are a 5 MHz
8085A with a bunch of ROM and RAM ( all separate from the main CPU). The
carriage motor is a 48vdc Litton model with hi-res encoder. I remember
hearing that the motor cost almost as much as the rest of the printer--it's
a finger-breaker too. To get the half-dot vertical offset for multipass
printing, it uses a geared-down stepper for the paper feed.
Cheers,
Chuck