From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: References: <4e6ca2050908140304i1a78ad52i131fdb5a96560f41@mail.gmail.com> <4e6ca2050908140429t4fbba7deieec0ad9dbeb52ae5@mail.gmail.com> <3aaafc130908141737k53505228k365717d5a296980@mail.gmail.com> Date: Fri, 14 Aug 2009 21:48:18 -0400 Message-ID: <3aaafc130908141848n7a24547as64078c05e71c779@mail.gmail.com> From: "J.R. Mauro" To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [9fans] HP: Printing with the Illiterate Topicbox-Message-UUID: 4aa69028-ead5-11e9-9d60-3106f5b1d025 On Fri, Aug 14, 2009 at 9:06 PM, Russ Cox wrote: > On Fri, Aug 14, 2009 at 5:37 PM, J.R. Mauro wrote: >> IJS is probably it; that's the PCL driver for the home-office class prin= ters. > > IJS is not PCL. > > IJS is a custom protocol that is spoken between a bitmap-producing > program like Ghostscript and a bitmap-printing program like /usr/bin/hpij= s > http://svn.ghostscript.com/ghostscript/branches/mtrender/ijs/ijs_spec.pdf > > /usr/bin/hpijs speaks IJS to Ghostscript (or whatever is on standard > input/output) and speaks a new HP protocol called LIDIL to the printer > on the other end. =A0Rather than commit to a full specification of LIDIL > and have to worry about backwards compatibility in the future, > HP chose to use IJS as a shim protocol and distribute a binary > that talks to the printer (source is available but it's still a binary). > > PCL is not in the picture. =A0Getting PCL out of the picture is exactly > the reason that IJS and LIDIL were introduced, because LIDIL is > basically "here is a bitmap" whereas PCL is a real language that > requires actual memory and computing power inside the printer. > LIDIL moves the memory and computing requirements out of > the printer into the computer proper. > > Russ > > I thought IJS was also used to turn a raster into PCL, since IIRC some non-business-class HP printers come with a stripped-down PCL 5e or some such. I'm probably wrong again, though. I try to not think about the HP PDLs too much. Probably it's not IJS I'm thinking of and some other cruft from HP -- it's been a long time.