12 May
2010
12 May
'10
5:58 p.m.
On Wednesday (05/12/2010 at 06:47PM +0100), Tony Duell wrote:
yes... and to make matters worse, some of the devices were soldered
in without sockets too! I first suspected the 8279 display+keypad
controller and so I had to sacrifice it by cutting the pins off the
package and then desoldering each pin one at a time. Sadly, that did
not fix the problem and I wasted a nice ceramic packaged 8279 circa 1976.
This board likely had a different history than other SDK-85 since it
was built into this Philips logic analyzer demo system. It's possible
Philips bought the boards assembled from Intel or some middleman who
assembled them in this static configuration.
yes... or shorts. Do you call them shorts over there? aka, short pants.
I still have the scars on my leg from dropping solder blobs onto them
while wearing shorts at the bench as a kid. Not cool.
--
Chris Elmquist
That's on the ToDo list. Unfortunately the
ROM extension location at A15
has no socket installed and all the holes are flowed over with solder. So
The PCB was probably wave-soldered with no socket in place. Seems
strange, on an experimental machine like this not to fit the expansion
socckets, but anyway... I need to
carefully solder-suck, solder-wick those clean before I can
install a socket. Boards of this age are quite fond of letting the pads
loose when you heat them up so I need to do this slowly and carefully.
The best way I've found to do this is to hold or clamp the board
vertically, melt th solder with an iron on one side and suck with a
solder sucker from the other. It's not too bad doing it for a 40 pin
socket, it gets boring fast when you have to clear out 16 or 32 16 pin
locations for a memory upgrade (been there, done that, don't wear
t-shirts ;-))