Lisa "Screen Kit" downgrade?

From: Scott Ware <ware_at_xtal.pharm.nwu.edu>
Date: Fri Oct 17 18:01:31 1997

I've recently started work on a "Sun Remarketed" Apple Lisa 2. I would
like to configure this machine so that it can run the Lisa Office System;
however, the "screen kit" upgrade has been installed. The screen kit
upgrade changes the resolution of the display from the Lisa standard 720 x
364 to 608 x 431 to better approximate the Macintosh aspect ratio.
Unfortunately, the Lisa Office System still writes to video memory
in the 720 x 364 format, which yields a garbled screen.

The screen kit upgrade consists of three ROM chips - the high and low boot
ROMs and the video state ROM, as well as a transformer that presumably
steps the voltage to one of the deflection coils up (or down). Swapping
these chips for the original Lisa versions and removing the transformer
should restore the Lisa's rectangular pixels and allow both the Office
System 7/7 and MacWorks to run.

If anyone has an extra set of these chips (Apple boot ROM numbers 341-0175
and 341-0176 and video state ROM number 341-0229) lying around or knows of
an inexpensive source of them, let me know. Otherwise, I'll contact Sun
Remarketing to see if they have any that were removed from the machines
that they have upgraded. Unfortunately, I suspect that Sun's supply of
these met the Logan Landfill of Lisae long ago.

--
Scott Ware                      s-ware_at_nwu.edu
Received on Fri Oct 17 1997 - 18:01:31 BST

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