Re: Fatal system error-> 0682 -- and the W1 jumper pins

[Rubywand <rubywand@swbell.net>]

"mystix"@direct.ca@direct.ca writes ...
> 
> What the hell is it?
> 
> I've got a ROM 01 system that won't allow me to go to the control panel,
> and everytime I do I get this error. Also if I try to reset I get a message
> Cannot Reset $0602
> 
> One other thing, in the CDA menu, there is only
> the Control Panel selection,
> no Alternate Display menu.
> 

     The error number you mention above (0602) is different from the one in
your message title (0682). An 0602 error is "Cannot Reset Event Manager". A
check of the Toolbox Ref Manuals indicates that this error occurs when the
Event Manager is busy doing something and an attempt is made to Reset which
would abruptly terminate the EM. Not sure what fault might produce this error.
Probably, a RAM messup (resulting from bad RAM or a buggy program or a power
glitch) could.


     For Error 0682, here is a snip from the newsgroup FAQs which may help:

>>
0682 "bad que handler"-- My IIgs crashes with a Fatal Error $0682 whenever I
have my expansion memory card plugged in and try to access the Control Panel.
Also the Alternate Display mode seems to be missing and stuff won't boot.
What's wrong? 

     Error $0682 indicates a data structure maintained by the Event Manager is
corrupted.  It is either the Event Queue itself, or something related to it.
The most common cause for this is buggy software which has overwritten memory. 

     The second most common cause is a faulty or incorrectly configured memory
expansion card (or bad RAM on that card).  The event queue normally lives near
the top of "fast" memory, so it is always located in the memory expansion card
if you have one. 

     Similarly, the list of items in the Desk Accessories menu is in RAM, so
lack of Alternate Display Mode points to memory corruption of some kind.
--David Empson 
<<

     It may help to run the IIgs diagnostic self-test. The IIgs self-test is
activated by pressing Open-Apple and Option on power up, or Open-Apple,
Option, and Reset. (See http://home.swbell.net/rubywand/Csa2ERRLIST.html#002
for more info.)



> Anyone know what the jumper pins next to Slot 1 is for? It's labeled W1.
 ....

     What the W1 jumper pins do is allow you to change the way the 7M clock
signal going to the IIgs Sound controller IC's is handled.

     With no jumper, the 7M signal is inverted. If the jumper is connected,
the 7M signal is not inverted. (The jumper pins control the state of one input
to an XOR gate through which 7M is fed to the Sound IC's.)

     As to why one would jumper (or not) the pins, I do not know. A guess is
that a 74F86 (XOR IC) on the ROM-01 motherboard had a spare gate and Apple
designers thought it would be cool to use it as a buffer to reduce loading on
the 7M output and/or to get a 7M better suited to clocking the Sound IC's. The
jumper pins were added in case the phase of 7M at the Sound IC's needed to be
changed to accommodate some plug-in card which might be developed later.

     Evidently, the W1 pins are usually left un-jumpered-- no connection. (At
least, this is their status are on our main IIgs and a spare.)  This is kind
of interesting because the ROM 3 IIgs does not seem to use any gate between 7M
and the Sound IC's. So, a ROM-01 IIgs with W1 unjumpered has /7M (7M inverted)
going to the Sound IC's whereas a ROM 3 sends 7M directly (uninverted) to the
Sound IC's.




Rubywand