[comp.lang.postscript] Obscure LaserWriter features

alex@grian.cps.altadena.ca.us (Alex Pournelle) (08/29/90)

woody@chinacat.Unicom.COM (Woody Baker @ Eagle Signal) writes:

>If you hook up to the 25 pin serial port in interactive terminal mode, AND
>you jumper pin 4 to pin pin 22, and power the laser up, you will come
>up in the RED STONE monitor.

Uuuuh--is this the reason there's an ADB connector on all LaserWriter II
series machines?  So you can hook a video-out adapter to the laser feed
and a keyboard to the ADB port and debug the printer?

That's half a :-), by the way.  I'm still clueless why there IS an ADB
port on the furshlugginer printer.

	Alex
-- 
		Alex Pournelle, freelance thinker
		Also: Workman & Associates, Data recovery for PCs, Macs, others
		...elroy!grian!alex; BIX: alex; voice: (818) 791-7979
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fleming@cup.portal.com (Stephen R Fleming) (08/29/90)

Alex,

The canonical explanation for the ADB ports on LaserWriters is to control
the plethora of third-party envelope feeders, bin feeders, continuous-feed
rollers, and other aftermarket goodies that are crowding dealer shelves.

What?  Not at -your- dealer?  Well, you're obviously not patronizing
dnalretupmoC.  Right this way, through the Looking Glass...

+--------------------------+-------------------------------------------+
|  Stephen Fleming         |   In ten years, computers will just be    |
|  fleming@cup.portal.com  |   bumps in cables.       --Gordon Bell    |
|  CI$:   76354,3176       +-------------------------------------------|
|  BIX:   srfleming        |   My employers may disagree vehemently.   |
+--------------------------+-------------------------------------------+

alex@grian.cps.altadena.ca.us (Alex Pournelle) (08/31/90)

fleming@cup.portal.com (Stephen R Fleming) writes:

>Alex,

>The canonical explanation for the ADB ports on LaserWriters is to control
>the plethora of third-party envelope feeders, bin feeders, continuous-feed
>rollers, and other aftermarket goodies that are crowding dealer shelves.

>What?  Not at -your- dealer?  Well, you're obviously not patronizing
>dnalretupmoC.  Right this way, through the Looking Glass...

Thanks to the six (including Stephen) people who reported this answer to
a really obscure one!  And they say USENET isn't valuable....

One person mentioned he'd seen this info on a brochure for a
sheet-feeder, so p'haps one exists.  And copy-controls, LCD displays,
bin selectors, etc--at least, those were suggestions.

Another mentioned that some used ADB to communicate directly with the
printer; is this actually faster than AppleTalk?

I'm still wondering why you can't use SCSI to talk to your LW IINTX; I'm
also wondering why your font cache can't live on your computer's hard
disk.  (Doubtless several people will call me nieve, which is one reason
that USENET is called USELESSNET by its detractors.)


>|  Stephen Fleming         |   In ten years, computers will just be    |
>|  fleming@cup.portal.com  |   bumps in cables.       --Gordon Bell    |

								In ten years, lawyers will just be
								bumps in roads.		   --Shakespeare

								In ten years, computers will say,
								"Cables?  Where we're going, we don't
								need cables."		   --Nobody, yet

			Alex
-- 
		Alex Pournelle, freelance thinker
		Also: Workman & Associates, Data recovery for PCs, Macs, others
		...elroy!grian!alex; BIX: alex; voice: (818) 791-7979
		fax: (818) 794-2297    bbs: 791-1013; 8N1 24/12/3

woody@chinacat.Unicom.COM (Woody Baker @ Eagle Signal) (09/02/90)

In article <1990Aug31.082117.6829@grian.cps.altadena.ca.us>, alex@grian.cps.altadena.ca.us (Alex Pournelle) writes:
> 
> Thanks to the six (including Stephen) people who reported this answer to
> a really obscure one!  And they say USENET isn't valuable....
>

Where did you ever hear that ?????


> 
> Another mentioned that some used ADB to communicate directly with the
> printer; is this actually faster than AppleTalk?


IF so, it certainly should be faster.  The curious thing is, where is
the documentation for the ADB connector, it's pinouts, and what it does.

> 
> I'm still wondering why you can't use SCSI to talk to your LW IINTX; I'm
> also wondering why your font cache can't live on your computer's hard

Not at all.  You can do it with limitations.  I believe Don Lancaster
has done it on a limited basis.  It appears that the major problem
is interfacing to the disk operating system.  It apparently blows
up if you just look cross eyed at it.  Now, it occurs to me, that one
should be able to take a computer with a SCSI interface, and write
a program to make it look like a hard disk to the laser.  Once that is
done, then your font cache should work transparently, and you should also
be able to precompile documents and dump them to the printer over the
scsi port.

Since I have not had a chance to play with a laser with a hard disk, this next
stuff might bee entirely off base, but it seems to me that one could
use rhe   run   operator to execute postscript programs off the hard
disk from within the printer.  If you could then write to the printers
disk from a computer, you could simply use the hard disk as a very large
print buffer, among other things.  This being America, and the free
enterprise system etc etc, I am sure it won't be long before some nifty
little box shows up that hooks to the laser scsi port, and then allows
you to daisy chain as many computers and harddisks as SCSI allows.  There
are several SCSI controller chips on the market.  I'n not a hardware
person, or I probably would have investigated this already.

Cheers
Woody
> -- 
> 		Alex Pournelle, freelance thinker
> 		Also: Workman & Associates, Data recovery for PCs, Macs, others
> 		...elroy!grian!alex; BIX: alex; voice: (818) 791-7979
> 		fax: (818) 794-2297    bbs: 791-1013; 8N1 24/12/3

minow@mountn.dec.com (Martin Minow) (09/04/90)

In article <1990Aug31.082117.6829@grian.cps.altadena.ca.us>
alex@grian.cps.altadena.ca.us (Alex Pournelle) writes:
>
>I'm still wondering why you can't use SCSI to talk to your LW IINTX; I'm
>also wondering why your font cache can't live on your computer's hard
>disk.

One good reason why font caches ought not to reside on the Mac hard
disk is that the Mac OS wasn't setup to handle multiple SCSI bus
initiators, and you're liable to have wierd crashes if you do SCSI
operations when the system isn't expecting it.

Since hard disks are hovering around $10/Mbyte quantity one, I would
think that using the main system's disk as a font cache would be
false economy.  If nothing else, the Laserwriter's font accesses will
slow the system down somewhat.

>  (Doubtless several people will call me nieve, which is one reason
>that USENET is called USELESSNET by its detractors.)

You're neive.

Martin Minow
minow@bolt.enet.dec.com

woody@chinacat.Unicom.COM (Woody Baker @ Eagle Signal) (09/05/90)

In article <1899@mountn.dec.com>, minow@mountn.dec.com (Martin Minow) writes:
> In article <1990Aug31.082117.6829@grian.cps.altadena.ca.us>
> alex@grian.cps.altadena.ca.us (Alex Pournelle) writes:
> 
> One good reason why font caches ought not to reside on the Mac hard

Who said anything about Mac's.  This perception that Mac's and Postscript
go together does not really hold water.  There are plenty of other platforms
that use the SCSI bus

> disk is that the Mac OS wasn't setup to handle multiple SCSI bus


You certainly should be able to get around this with the appropriate
low level hardware programming.  
> false economy.  If nothing else, the Laserwriter's font accesses will

It would not be a matter of economy, but rather one of speed.  Being able
to write to the disk at the full SCSI speed would ridiculously speed printing
up, as you can use the disk as a *VERY* large print buffer...

Cheers
Woody