--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pirelli/spca	Sun Jul 28 21:38:07 2013 +0000
@@ -0,0 +1,50 @@
+Tracing signal from Calypso A1 (address line 1, ball F2); expecting to see it go
+to ball H8 on SPCA552E.  On L1 the trace goes to (4326,756).  On L2 I see it
+branching - d'oh, it's address line A1, of course it will go to a ton of things!
+Looking for another signal to trace that would be point-to-point from Calypso
+to SPCA552E.
+
+Let's try tracing the bypass GPIO signal, presumably originating from GPIO 7 on
+the Calypso.  That's Calypso ball N2.  L1 goes to (4259,467).  L2 takes it to an
+inner via at (4290,471).  Found it on L5: goes to another inner via at
+(4370,1835).  Found it on L7: goes to (4270,2026).  On L8 it arrives at an SPCA
+ball which we are going to assume is A8 (bypass input according to the Nokia
+schematic).
+
+Deduced SPCA552E BGA orientation in steve-m's L8 picture: A1 in the LL corner,
+row A along the bottom.
+
+Accessible surface test points around the SPCA:
+
+* Along the bottom (the side toward the red and # keys) we have TPs for A8
+(bypass input) and C7 (Rxd1).  The TP in between these two seems to be connected
+through some inner layer, haven't traced yet.  The L8 coordinates of this TP are
+(4221,2119).  The hole seems to be slanted to (4228,2112) though.
+On L7 it goes to a large-looking via at (4196,1966).
+
+* On the side toward the antenna we have TPs for C2 (LcmCs) and D3 (LcmWr).
+
+* On the side toward the USB port we have TPs for J8 (Txd1) and H9 (HstRd_n).
+
+* On the side toward the green and * keys we have TPs for G4 (Suspend),
+  H5 (Trap), and J7 (LcmVs).
+
+The L8 trace from ball H6 (LcmMck) goes in two directions, terminating at via
+points (4066,1704) and (4270,1251).  On L7 the leg from (4066,1704) goes to
+(3722,1700), looks like a micro-via back to L8.
+
+Tracing Calypso PWL signal, starting with Calypso ball L7.  On L1 the trace from
+ball L7 appears to go to (3988,528); the trace from ball K7 (PWT/BU, no other
+functions listed in CAL000) goes to (4041,813).
+
+Tracing the mysterious PWT/BU first.  On L2 the trace from (4041,813) goes to
+(4211,1018), seems to be a micro-via back to L1.  On L1 it goes to some strange
+component pad at (4300,1186).  The component seems to be a resistor; the other
+side connection is unclear.
+
+Back to PWL.  On L2 the trace from (3988,528) goes to a larger via at
+(4010,554).  Found in on L7: goes to a micro-via to L8 at (3975,478).  On L8 it
+goes to another via back to L7 at (3784,664).  On L7 it goes to a larger via at
+(3635,839).  Found it on L5: goes to another via at (3512,1808).  Found it on
+L7: goes to a micro-via to L8 at (3459,1756).  There it appears to connect to
+the mysterious A3-90E component through some resistors.