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From: neff@hp-vcd.HP.COM (Dave Neff)
Newsgroups: comp.sys.mac.misc
Subject: Re: DeskWriter and System 7.0 -- problems
Message-ID: <1040008@hp-vcd.HP.COM>
Date: 23 May 91 15:23:45 GMT
References: <674696625.1@blkcat.FidoNet>
Organization: Hewlett Packard, Vancouver, WA
Lines: 33

Regarding DeskWriter 2.1 driver and system 7.

Yes, there are 2 main problems with the DeskWriter driver and system 7.

1.  The display glitch.  I wont go into details as to how it happens,
but printing with the DeskWriter under system 7 will make some of your finder
icons look a bit funny.   This is being fixed, but I have no date as
to when a new version of the driver will be out.

2.  Datacomm overrun with virtual memory turned on.  When VM is on,
the Mac insists on sending many K of data after we drop DTR.  Since we
only allow for 128 bytes to come in after we drop DTR, this leads to
an overrun.  Evidently while swapping VM pages, the Mac doesn't notice
the DTR is deasserted for a fairly long period of time.  We reported
this problem to Apple with beta versions of stystem 7 and hoped it
would not be present on the final version.  Unfortunately it is.
I really don't see how this could be a printer driver bug.  We have
hooked analyzers to the line and confirmed that the printer is dropping
DTR but the Mac continues to send large amounts of data.

There is a third more minor problem -- no spooler is presently
available.  Third party spoolers are being modified to support
system 7, but none that I know of are presently available.

For now, if you use a DeskWriter with System 7 the only way to use
VM is to use the DeskWriter in AppleTalk mode.  But this will cost
you the price of a couple of PhoneNet connectors (about $40) and
of course is not an option for those of you with old serial only versions.
I am sure the display glitch will soon be fixed, but the VM problem
is more of a concern.

Dave Neff
neff@hpvcfs1.HP.COM