2 Nov
2006
2 Nov
'06
3:32 p.m.
On 1 Nov 2006 at 23:23, Tony Duell wrote:
A bit. That's not a Sanders 700, though...
AFAIK, all Sanders 700s were RO models, and didn't have a keyboard.
While I would agree that most later impact
dot-matrix printers are of
little interest to me, there were some very odd machines out there that I
find fascinating. The Sanders printers that did up to 8 pases of the
printhead to produse very near letter quality output (one of the later
ones of those was build on a DIablo 630 chassis, and the output is very
much daisywheel quality, for all there's a 7 pin dot matrix head in
there).
Like the printer in this thing:
http://www.sydex.com/durango/durango.html
Since it was pretty much Diablo people working on the printer in this
box, they knew about the Sanders work and developed their own
version, complete with downloadable and prop-spacing fonts. With a
That was the main deficiency of the Sanders 700. Fonts came on ROM
cartridges which plugged in in front of the carriage area. There was no
way to download them (although the hardware had the Wr/ line on one pin
of the cartridge slots, so a RAM cartridge would have been possible,
AFAIK the firmware didn't support it).
Still, it was an improvement on the older Sanders 12/7 (I have one of
those too). That machine had the fonts on EPROMs that you plugged into
one of the PCBs inside. Some ROM sockets took 2708s, some (3-rail) 2716s,
some 2732s. You pretty much had to order the font on the right type of
ERROM to fit whac sochets you had free...
film ribbon, it's very difficult to tell that a
daisywheel didn't do
the printing. And you could print very large characters, unlike a
daisywheel. This one used a 9 wire printhead, however.
The Sanders 700 electronics allowed for a 9 pin head -- I think that was
called a Sanders 900 printer. I don't have one, though.
It uses a dedicated 8085 on a Multibus-sized PCB, along with the CRT
controller. A second PCB holds all of the printhead drivers on a
The Sanders 700 has 3 microprocessors in it. A Z8 for character input. A
Z80 to format the lines, handle the fonts, etc. And another Z8 to control
the mechanism.
The main DRAM, hung off the Z80, is 9 bits wide. No, not 8 bits + parity,
but a full 9 bits. For a 9 pin head, of course.
The older 12/7 has just one Z80, but a lot of TTL + PROMs to drive the
printhead.
long heat sink, along with the drivers for the
carriage motor (a 48v
Litton DC motor with optical position encoder).
I can't rememebr what the Sanders 700 uses. I know the paper feed and
ribbon feed aare stepper motors, and I think the carriage feed is too.
Certainly the 12/7 has stepper motors for carriage feed and paper feed
(and an AC mains motor for ribbon feed).
-tony