9 Nov
2012
9 Nov
'12
5:41 p.m.
On 11/9/2012 6:15 PM, allison wrote:
On 11/09/2012 07:50 PM, ben wrote:
That is a mechanical issue, not the idea of charging a drum with a laser.
The old, cheaper hardware, faster software problem here. I don't think
software has yet to solve the real problem of modern printers,
is that text on the screen does NOT match the printed page, but that is
off topic.
On 11/9/2012 5:30 PM, Alexandre Souza - Listas
wrote:
Well if you could access the toner drum directly from the host cpu, I
am sure you could emulate a generic mono-spaced printer like a TTY in
16K including the printer fonts.
Ben.
Actually no. To do that you need to be able to process the data rapidly
enough to lay down dots
as the drum rotates. Tell me
what toner does a P112 use or is that used to color the 1MB of
ram??
Well, a 64-K CPM system will not print raster graphics with ease on
a Laser Printer...You need more RAM!
:oD
Well, at least I tried :D
The key thing for Laser printing (or any page printer)
is the bit image
need to exist before
the paper moves or at least be preprocessed so that the raster image
processor can fill
a "band buffer" . The Video dot rate for a DEC LN01 (xerox 12PPM
engine) was about 7mhz.
The early character only version use a 12mhz 80186 with 8089 to keep up,
The system IO
to the host was handled by the 8089. Oddly the 8PPM LN03 Ricoh based
engine was not much
slower on the video clock. In the late 80s there were two lasers often
those that were
band buffer and generally limited to text and limited graphics and a
higher priced version
that had enough ram to buffer the page so the image could be composed
before the paper
was even moved.
I think history of Time-Sharing computers had a big impact here. You needed
BIG fast page laser printer to share between users, so high speed
printer was
needed. Speed I don't think changed much over the years, but build
quality HAS dropped.
Actually I use my CP/M-80 system to lay down images on
a real
Laserjet4L. The price is that
I need to run the system for a long time to create bit images to
transmit. That takes hours
even with ram and bit of buffering to hard disk. Even then the printer
is doing much of the
heavy lifting.
Custom software, or using a driver for a text processing package?
Allison
Ben.