User`s guide

The escape is a likely key for this as it is located where it can easily
contact the case but does not exhibit any problems until another key is pressed
and then that key will repeat.
______________________________
From: Rubywand
If the KB Encoder IC or the IOU IC is loose or has pins making poor
contact, you could get the symptoms described.
Open the case and locate the KB Encoder (a big, 40-pin IC on the right side
of the motherboard just to the right of three ROMs). Use a small, thin-blade
screwdriver to scootch up the IC. (You want to get some lifting for all pins,
even if you end up just removing the IC.) Press the IC back into the socket.
Do the same with the IOU (a big, 40-pin IC just to the left of the three
ROMs).
The idea of lifting up and re-socketing each IC is to let the socket
contacts scrape a fresh connection with each pin on the IC.
______________________________
From: [e-mail] (System Administrator)
017- A while ago someone posted about how to read the
joystick on a GS in native mode. They said that it was
possible to read both paddles at once and therefore get
much more accurate readings?
Only the high bit of these locations is valid. When the high bit of either
location becomes 0 then the corresponding analog input has timed out.
You will actually get more accurate results by reading them one after the
other with the accumulator set to 8 bits wide and the index registers used to
hold the counts (16 bits wide). This allows for a much faster loop, giving
better resolution. Assuming that this routine is called from full native mode,
the following code will do the trick:
strobe equ $C070 ; analog input timing reset
pdl0 equ $C064 ; analog input 0
pdl1 equ $C065 ; analog input 1
start php ; save processor status register
phb ; and data bank register
sep #%100000 ; make accumulator 8 bits wide
lda #0 ; make data bank = 0
pha
plb
ldx #0 ; initialize the counters
txy
lda strobe ; strobe the timing reset