[comp.laser-printers] SCSI printers

TOM@PENNDRLS.UPENN.EDU (Thomas D. Denier) (01/24/90)

The November 14, 1989 issue of "PC Magazine" reviewed 109 printers,
including a variety of laser printers. I think at least one of the
laser printer reviews mentioned SCSI as a host interface.

The printers reviewed were all relatively low-volume printers by the
standards I am accustomed to. As nearly as I could tell, none of them
were designed for much over 10,000 pages per month, and most were
designed for volumes considerably lower than that.

liam@cs.qmw.ac.uk (William Roberts) (02/06/90)

In article <9001230339.AA13652@crayola.cs.UMD.EDU> mr@ritd.co.uk writes:
>Does *anybody* have any info or leads for a laser printer which can
>be driven via a SCSI interface? I have been looking for some time
>without joy.
>
>Note that I am aware that various machines have a SCSI port but restrict
>this for use with local disks, typically holding fonts. I want to use
>the SCSI to send large bitmaps at high speed to the print engine. If it
>helps you, we are a Sun OEM well versed in SCSI device driver stuff.

Apple LaserWriter IISC is driven through the SCSI port and
performs well printing prepared bitmaps at the 300 dpi
resolution of the marking engine. It doesn't use PostScript
though, so you'll have to put some effort into finding
out/understanding what it does speak (QuickDraw-based).

Thought: You can have two devices which as masters on a SCSI
bus provided that they don't both try to control the
bus/devices at once. How about a PostScript-based printer with
a SCSI disk, daisychained onto your Sun SCSI interface. The
normal RS232 interface is used to send print jobs consisting of
"print file X from the disk", and your print spooler stuff does
whatever is necessary to write files directly onto the
filesystem structure on the "font disk".

Sounds rather "Heath Robinson" but it should work.

-- 

William Roberts                 ARPA: liam@cs.qmw.ac.uk
Queen Mary & Westfield College  UUCP: liam@qmw-cs.UUCP
Mile End Road                   AppleLink: UK0087
LONDON, E1 4NS, UK              Tel:  01-975 5250 (Fax: 01-980 6533)

yap@ME.UTORONTO.CA (Davin Yap) (02/10/90)

liam@cs.qmw.ac.uk (William Roberts) writes:
>Thought: You can have two devices which as masters on a SCSI
>bus provided that they don't both try to control the
>bus/devices at once. How about a PostScript-based printer with

Both masters may try to control the bus simutaneously, but the one with
the highest logical unit number (0 <= lun <= 7) prevails, that's 
why the lun of the scsi controller board in your machine is set at 7.

Davin
--