Re: Second Sight red border

[rubywand@aol.com (RUBYWAND)]

In article <4kfvtu$5vc@acmex.gatech.edu>, gt8624a@prism.gatech.edu
(William Sheldon Simms) writes ...

>>
I just got my upgraded SS board back from Sequential (finally) and my
GS is a little flakey with it in. About half the time I boot the system,
or maybe a little more, there is a red border around the Apple IIgs
text screen that appears first during a boot. This seems to mean
"SS crash ahead". I'm just wondering what this red border is supposed
to signify.
<<

and Matt Portunr (mportune@telerama.lm.com) writes ...

>>
Ever since I got my SS board, it's had this "problem".  ALso, it's not 
always red.  Sometimes green, blue, purple, white, etc.  And sometimes 
none at all!  It's completely random. ....
<<
    The border color changes may be some kind of diagnostic output.
Perhaps Sequential's tech person can tell you what fault is indicated by a
'red border', etc. crash.

    Since the boards were, supposedly, tested, the problem may be with the
computer. According to various reports, SS seems to be something of a
power sucker. This results in added noise on the +5V and +12V lines.

    Several variables come into play when determining whether or not the
added noise is severe enough to produce system glitching: skimpy Power
Supply leads, a poor PS-to-Motherboard plug connection, fractured solder
at PS socket pins on the MB, skimpy Slot plane power traces, Slots
populated with other power-hungry boards, placement of Slot boards, a IIgs
on the same AC line as a dimmer switch, ... .  Also, a ROM-01 machine is
supposed to have a noiser Slot plane than a ROM-03 machine.

    All of which would explain the wide variation in reported SS
experiences. The cure is to  (1) beef-up +5, +12, GND power supply leads
to something like #12 gauge;  (2) clean the PS plug and socket or replace
with gold-plated versions;  (3) re-solder plug contacts on motherboard; 
(4) add #16 gauge runners for +5 and +12 from the PS socket to Slot 7 and
Slot 3 as well as to whichever Slot holds the SS board.

    When done, check resistances from socket +5 to each Slot's +5 point. R
should read very close to zero Ohms. Do the same for +12 and GND. Add any
needed additional runners.

         

Rubywand