jhs@disunix.UUCP (04/21/86)
As I am unable to deduce an E-mail address to reply directly to Bill at
Tektronix, I am posting this to the net -- my apologies to those not
interested in 256K upgrades!
Bill's questions re: the Newell 800XL upgrade follow. My answers are
bracketed by "******" before and after.
----forwarded questions and ****** answers ******
In the instructions, #s 7, 8, 9 and 10.
7. Am I to assume that the five pins are to be pulled from the socket
bent horizontally and have the wires soldered to them?
****** I think this is what Wes was suggesting. However, I chose to leave the
pins in the socket and tack-solder to the portion accessible from above. I
used a piece of ribbon cable from the PIA to the 256KXL board, with seven
wires at the 256KXL board end, two of them branching off midway, and the
remaining five going to the PIA. I taped the ribbon cable to the top of the
PIA and made the free end a little longer than necessary to allow for future
repairs. I then separated the five wires and tack-soldered them carefully to
the PIA pins. If you use this method, use a fine-pointed soldering tip and a
low wattage and do each wire as quickly as possible. I advise first tinning
the end of each wire and tinning each IC pin with a very brief application of
heat. Then let it cool off a minute or so and attach the wires with another
very brief application of heat. Since both parts are pre-tinned at that point
the tack soldering is easy. In my opinion, the use of ribbon cable makes the
installation much neater than it would be with hookup wire.*****
8. This pin is to remain in the socket? Sure not much to solder to!
******If you trace the board, there is a feed-through hole near the center of the
board that is connected to this pin. This is where I connected to this
point.******
9. Do not see a feedthru hole, again I assume pin stays in socket but
soldered to it?
******There is indeed a feedthrough hole behind the ANTIC chip, but it isn't
obvious which one it is. Check for continuity with Pin 9 via an
ohmmeter.******
10. This appears to be the right hand pad (looking from front to back)
Does anyone see what I mean?
****** I believe you are. It is not the end
closest to Pin 1 physically but the OTHER end which is connected electrically
to Pin 1. I think the words "inside most" mean further from the edge of the
board.******
It seems to me that the cable from the Newell board to socket U27 is too long
What are you supposed to do with it or do you reverse the board upside down?
Does anyone see what I mean?
******After some experimenting, I found that the best way to mount the board
was to fold that cable over in the middle and mount the board upside down
resting on the chips below it. It sits at an angle almost exactly parallel
to the top shield cover that way. I put some foam strips on the cover to hold
it firmly in place when the cover is installed. It worked out very well, and
allows you to turn the board over for inspection if needed while leaving it
connected.******
One comment: I can see why people do prefer the RAMBO XL kit to the Newell
kit, the instructions are 100% better. Newell's board may be technically
better, but the instructions are loose and goosy. Also, the Newell board
has a lot of leads bent over on the back almost touching or touching the
adjacent runs. Much cleanup of the board is required.
****** I haven't seen the RAMBO board documentation, but I agree that Newell
could do a better job on the documentation. I also noted the same problem
with component leads that looked as though they might be shorted. I clipped
them off also. ******
Newell talks about routing the jumper wires thru the cartridge slot clip
holes, but if you do this, how do you clip the plastic part on? It would
definitely be an advantage to be able to run the wires underneath, but I
do not see any practical way to do this. Further examination of the board
may show me an area where a feedthru hole could be drilled, but in my first
examination, I could not find any area big enough.
****** I also couldn't see any good way to run wires to the bottom. That is
why I chose to solder to the top of the PIA chip.******
------- End of Forwarded Message
I have no comments on the 1200XL or 130XE cases as I have no experience with
them.
-John Sangster
jhs@mitre-bedford.arpa