Posts of Interest from
Rec.Games.Pinball
Q: Hi! I'm fixing a Game Plan MPU-1 board from a Star Trip
cocktail
machine.
Game Plan MPUs have a power-on self-test routine that is almost like
the one of Bally pinballs. The manual says that I should get a
sequence of six LED flashes.
Now, after rebuilding the part of the board that was damaged by the
acid, I get only ONE brief flash.
It is exactly like the first flash of Bally "-35" boards.
Since the manual doesn't say whether the first flash should be short
or not, I'd like to know if it is a "good" first flash indeed.
A: A brief flash usually means that there is a problem with
the RAM or
RAM select. I would be looking for battery corrosion on the traces...
John :-#)#
jrr@flippers.com
Q: Hi All-
Does anyone have any info on ROM jumper settings for Game Plan MPU
boards? Speficially, game is Andromeda, and I believe uses the MPU-2
board. Need settings for installing 3 2732 eproms on the board.
I've been dealing
with a board that had only two chips on it (one 2732 and one 2716),
which works but works really weird. The replacement rom images I have
are for three 2732's. Not sure which the game is supposed to have.
Any jumper settings related to the ROM chips/sockets that you can
provide would be helpful,
Thanks!
--
Ray
Johnson
A: Game Plan did not use jumpers, you have to cut/solder traces. Rather
nasty and a bit vague as to position. i made a couple of colour coded
pages for the shop that more or less outline the required jumpers.
The schematics do show the required changes, look on the bottom right
corner for the Eprom and then beside it is the number to follow. #3
means to cut/join the #3 traces...
I believe this board was designed by committee...
I believe Andromeda did use three 2732's, they are contiguous on the
memory map starting at 0000h as I recall. Email me Tuesday during the
day when I am at the shop and I should be able to find the info for
you.
John :-#)#
Question:
Does gameplan pinballs allow you to test the MPU board while not connected
to the playfield/solenoid board/light board?
The thought has crossed my mind that the LED diagnostic flash maynot occur
if the system is engineered so that all boards need to be connected, even to
get the first initial flash. (CTC)
Question:
Okay so the super nova game is in question here (1979), damm LED never
flashes, signals all show present/normal (test points) as do the votages,
still no first flicker on the LED. the LED and transistor test "okay" as
well.
Remaining: ROM chips: I got this game from an x-operator/repair guy, get a
feeling I am struggling with a "hacked"/screw-up by him game. There are 3
ROMs, U12, U13 are 2716. The U26 Rom is not an eprom Looks like it onlt bhas
the company number stamped on it. How do I identify this rom chip? All
numbers on it don't cross to anything. See I am wondering, because the
board settings didn't seem right (jumopers) if this guy put in new ROMs
without correctly jumping the board. but I can't get the board set tright
for the U26 unless I know what it is? Do I assume it is a 5200 series?
IC reads: 7944e
C28785M
26-30020N
I don't yet have an ROm programmer so how can I even be sure they work?
Mainly now I want to know if I have to worry about "every" connector being
perfec on the cable harness just to get the MPU-2 LED flash (first one at
least) Also do the switch settings have an effect?
Anyone? Anyone have a clue?
--
A: Its one of the PROMs. Depending on the jumpers you have alluded to
before. I'd assume it was a 9316 style pin-out.
The CPU can be tested with just the power connector hooked up to it.
The first steps to fixing this CPU is usually to strip the board of
most of the components in the area of the battery as far down as the
CTC chip, and scour the PCB of the corrosion there. Even the reset
circuitry discreets may be corroded (cap.s)
Good luck. It *can* be done.
Ace
Ni-Wumpf Ltd.
A: (2) We've fixed a few GP boards, and they can be run with just the power
connector. Corrosion and bad sockets will stop any flashes-it is one
of the most poorly designed MPU's that I have run across.
The U26 is a 9316, and if pin 20 is tied to Gnd, then it should be set
up correctly. I am not sure if U12 and U13 are wired up correctly, but
on each of then pin 21 must be tied to Vcc, if not, then the board is
not strapped correctly. Ugly strapping on that board, really poorly
laid out.
John :-#)#
Posted:
Well, this annoyed me! I couldn't get my CAT Box to read the
ram/cmos/prom on the cpu I was trying to service, so spent hours
checking traces etc. Put the board away for a couple of weeks (what I do
with offending game boards untill my subconcious has a chance to think
about it) and today took another look at it. A different customer had
brought in the SAME board that he too needed service, so when I got it
running (simple corrosion and a few parts, IC sockets later), I tried
the swap test. Curious, the "sick" board worked with the good ones CMOS
Ram and Z80 cpu, yet the 5101's that I substituted for the 6551's
didn't. Strange. Aren't all 22 pin CMOS Rams the same pinout, they look
the same with a cursory check. Took down the IC Master and Ah-Ha, the
difference is that the 6551 uses pin 17 as a NEGATIVE chip select and
the 5101 uses pin 17 as a POSITIVE chip select. So now I knew why my
poor CAT Box failed, the New Cmos Ram wasn't being turned on when I
thought in fact it was coming on with the PROM and thus giving very
STRANGE results!
So there you have it.
Watch out for assumptions about IC's.
Unfortunate that this was the first Game Plan cpu that I worked on in
the past three or four years, but I hadn't had such an interesting
STUPID problem for a while. Sigh. I must be getting too old for this
racket...
Sigh.
:-#)#
Reply: Begin Andy's post------------------------------------------------------
How to replace a 5101 with a readily available alternative....
Quick introduction:
The 5101L is a low power CMOS memory which is used in some MPU units
as non volatile (battery powered) memory for storing high scores, etc.
While there doesn't seem to be any problem sourcing them in the
States, I had trouble trying to get hold of one in the UK. What
follows is a description of how to make a simple adapter which will
allow you to replace a dead 5101 with a readily available alternative,
without modifying your MPU board, and save you money at the same time
(in the UK, at least).
Just to clear up any confusion: If your machine is working OK, then:
*there's no reason to do this*
(It won't make it better, stronger, or faster)
Alternatives to 5101
The 5101 is a low power CMOS stores 1024 bits as 256, 4bit 'nibbles'
About the smallest capacity, widely available chip which could replace
it is the 6116 which stores 16384 bits stored as 2048, 8 bit
bytes. It's low power CMOS, with 100ns access time, standby current
10na, and data retention guaranteed down to 2v. Because the 6116 has
more data and address lines than the 5101, we can play a few games to
make life simple when making an adaptor.
One thing about the 5101 - It has separate data in and data out pins.
The 6116 hasn't. This conversion only works where these inputs and
outputs are connected together - Check your board, pin 9 should be
linked to pin 10, 11 to 12, 13 to 14 and 15 to 16.
You will need:
A 6116 memory chip. Suffix letters don't matter, as long as it's
described as *low power* CMOS.
A 24 pin, 0.6" pitch IC socket to suit the 6116
A piece of 0.1" matrix strip board approx 12 holes square
22 thin PCB solder pins / lengths of tinned wire / wire wrap pins
Possibly a 22 pin, 0.4" pitch socket
(Remember, you can always chop down bigger sockets)
What you have to do
The idea is to make up a 'piggy-back' board to adapt a 24 pin, 0.6"
pitch 6116 chip to a 22 pin, 0.4" pitch 5101 socket:
VIEW WITH STRIPS ON UNDERSIDE
______________________________________
| | strips run this way
| . . . . . . . . . . . . | <===================>
| 1 1 |
| . . O . [o] x O . . . [o] + | . hole in strip-board
| I I I I | |
| . . O . [o] x O . . . [o] | | x break in strip on
| I I I I | | underside
| . . O . [o] x O . + x [o] + |
| I I \ I I | [o] IC socket pin
| . . O . [o] x O + x + [o] . | soldered to board
| I I \ I I |
| . . O . [o] x O . \. . [o] . | [ ] IC socket pin cut off
| I I \ I I |
| . . O . [o] x O . .\ . [o] . | O PCB pin protruding on
| I I \ I I | *underside* of board
| . . O . [o] x O + x + [o] . |
| I I | I I | + - + Wire link (between
| + . O . [o] x O + . . [o] . | holes marked '+')
| | I I I I |
| | + O . [o] x O + . . [ ] . |
| | | I I | I I |
| | + O . [ ] x O + . . [o] . | Note: no break between pins
| | I I I I | 11 & 12 of the 5101
| | . O . [ ] . O . . . [o] . |
| | I I I I |
| + . . . [o] x . . . . [o] . |
| |
| . . . . . . . . . . . . |
| |
|______________________________________|
END VIEW (to make things clearer)
__________
/-(XXXXXXXXXX)-\ <------- 6116, happy at home
| |
[X]==============[X] <------ modified 24 pin socket
======================================== <-- strip board
I I
I I <--- Pins to fit into 5101 socket
I I
The most awkward part is arranging some PCB pins, lengths of thickish
tinned wire, or whatever to stick out of the bottom of the board, to
plug into the 5101 socket. If you can get hold of 0.7 mm dia PCB pins,
then push these in from the component side of the board, and solder in
place. Alternatively, get the optional 22 pin socket, push 1/2"
lengths of tinned copper wire into all its holes, and feed these
through the stripboard. Trim off flush with the top of the board after
soldering. The socket with the wires in it can then be plugged into
the existing 5101 socket, without having to align 22 bent bits of
wire. (I used wire wrap pins, and had to force them into a cheapy 22
pin socket)
The official order of construction would be:
1 Break tracks where indicated (14 places)
2 Install 'pins' (22)
3 Install wire links (7) - note that two run diagonally
4 Modify the 24 pin socket by cutting off pins 10,11 and 16. These
must not contact anything:
1 [o]===___===[o] 24
[o] [o]
[o] [o]
[o] [o]
[o] [o] view is from *above* (pins down), as is normal
[o] [o]
[o]=========[o]
[o] [o]
[o] ->[ ]<-
->[ ]<- [o]
->[ ]<- [o]
[o]=========[o]
5 Install modified socket
6 After checking everything, plug board into 5101 socket, plug 6116
into board and go.....
Unofficial order of construction:
Modify socket, solder it in, saw out 'spreaders' so you can get at
the board to install pins and links, use screwdriver to make track
breaks because you've got a blob of solder next to where you want a
break so the rotating cutter won't work, plug in, unplug, check board
and find short, pray you didn't break anything, plug in again, and go.
(A friend told me this ;->)
Notes:
The CS1 (active low) OE and WE signals are fully implemented. The
CS2 (active high) line is patched to one of the address lines of the
6116, so it is theoretically possible that the chip will be active
when it shouldn't be, this doesn't matter, as any data written during
this time will be diverted to an un-used area of memory. Data cannot
read unless the OE line is low. (In the case of my machine, CS2 was
tied to the reset line, so was always high, anyway).
It might be an idea to fit a 100nf capacitor between pins 12 and 24 of
the 6116 socket (good practice), also I get a vague feeling that the
un-used data lines should be connected (via 1meg resistor, say) to
either ground or +5v, although this would make the wiring more
complicated.
It worked for me, if anyone manufactures them for profit, I want my
fee.....
Andy (andy@misterg.demon.co.uk)
End Andy's post--------------------------------------------------------
Reply 2:
Q: Just purchased a beautiful (non-working) Sharp Shooter by Gameplan
Game powers on...
GI's light
There is "white noise" followed by a constant tone.
No MPU flashes. 5V checks okay. I'm not sure where to check 24V...
My first step is going to be to burn new roms but any help would be
appreciated.
A; (1)
Game Plan MPU's are a real pain to fix if you are not using a Fluke or
Cat box to access the Z80 data and address bus and run the tests
directly on the MPU board. Otherwise you are reduced to replacing many
parts trying to find the fault. You could try substituting IC's from a
working board to the non-working one and see if that helps...
I would put a mark (white-out or some such) on the first set so you
can keep track.
The first step is NOT to burn new ROMs, they are rarely the problem.
Better to look for signs of battery corrosion first, then check the
RAM memory. I have found that these are the most common faults. IC
sockets are next. then CPU and ROM in that order.
John :-#)#
G: I'm working on a corroded Game Plan CPU pcb. There is a little circuit patch
board with two transistors that is supposed to be attached to the CPU board,
but it has been knocked off. Can anyone tell me how to wire this thing back in?
A: Hi, Charles! First wash the pcb with a solution of 50/50 white vinegar/water
to stop the strong basic corrosive (potasium hydroxide) that the ni-cad
leaked. If the sub-board was corroded off then you will be advised to replace
ANY components that show signs of corrosion-I have had transistors fail
because the corrosion worked it's way up the leads into the plastic and ate
the insides out of the poor thing. What a way to go-shades of ALIENS! The
sub-board that you are refering to is a watch-dog reset board. I recall that
it was not required for the board to run, just resets the computer if the CPU
locked up for any reason. (I might be wrong). I'll try to look it up tomorrow
when I get to the shop and let you know further tomorrow night. Sigh...I hate
ni-cads! Has anyone out there seen a good source of multi-FARAD caps that
could be used in place of the ni-cads and lithium batteries? I believe that
they were used on the conversoin playfield kits put out by Pintronics back
in the 80's.
:-#)>
Q: I have a Sharp Shooter II which seems to have a switching problem - When
the game is standing it thinks switches are being pressed all the time
(on and off though) it's like some ghost is playing it.
Someone mentioned it might be the 5101 chip - I could't find a 22 pin
5101 chip, but there are two 8334 chips simmilar to the 5101.
Anyone know anything about these? Anyone have a tester for these boards?
Thanks in advance for any help.
Aard
A: Hi!
This sounds like a problem with the switch matrix being grounded out somewheres.
Try disconnecting the switch matrix plugs from the MPU board and see if the
problem seems to vanish...
This game does NOT use 5101's, it uses a similar CMOS ram chip(actually a pair
of CMOS RAMs) BUT the chip selects are different! It won't cause your problem
anyways... Check you battery for leakage!!!
John :-#)#
Q: (Rick Herdliska)
I am a beginning pinball restoration enthusiast who
has accuired a Gameplan
Sharpshooter I cicra 1979. The playfield and backglass
are in great shape,
but much to my chagrin, after many hours of board
level chip replacement on
the MPU board, I have come to the reality that the
program ROM's may be bad.
The chip numbers are U12, U13, U26. I have been able
to readout data in U12
and U26, but U13 reads only DFFF's. Any help with
finding spare boards or
ROM's would surely be appreciated and make possible my
first pin restoration
A: How have you tried to read the data? The chip selects on some Game Plan
CPU's are HIGH, not LOW as you might expect from EPROMS. If these are
2716's or 25/2732's then, of course, you have a problem with the IC,
if on the other hand these are masked ROM's (no window) then you have a
version of CPU that used High and Low chip selects. Try reading the U13
with that in mind, I believe that the chip selects are pins 20 and 18.
If you can provide your CheckSum's for each IC I could let you know if
you have valid ROM's-please use a 2bite additive CS generator....
How many flashes are you getting on power up on the CPU? Should be 7....
:-#)>