RE: Wico XY Pattern Generator - Decoding Switches

>> HIS shows the crystal as 3.795 MHz, I wonder if he meant 3.579 (a very
common TV colorburst crystal).

OK, That helped me remember why this seemed a little rushed and incomplete.
Notice several things on the schematic are hand written (XTAL frequency and
my name). This is because I lost the source schematic in a disk crash and I
stupidly hadn't backed it up. The schematic I had was the last printout I
had and I thought it was done. Oh well.

I looked at the 7490 pinouts after Rodger's post and sure enough, they're
wrong. Looking on the web for data sheets showed that they are not all alike
between manufacturers. This will require some more checking.

Dave

From: owner-vectorlist@vectorlist.org
[mailto:owner-vectorlist@vectorlist.org] On Behalf Of Rodger Boots
Sent: Wednesday, November 09, 2011 1:17 AM
To: vectorlist@vectorlist.org
Subject: Re: VECTOR: Wico XY Pattern Generator - Decoding Switches

I was taking a look at your schematic (which I'll call "YOURS") versus the
one on ionpool.net (which I'll call "HIS") and have a few observations:

HIS shows the crystal as 3.795 MHz, I wonder if he meant 3.579 (a very
common TV colorburst crystal). Wouldn't make much of a difference, except
for availability.

YOURS has the R40 jumper connecting pins 2 & 3 of U2. That would keep U2
from working. His shows pin 3 connected to pin 11 which makes U2 a divide
by 9 counter.

U3 then further divides the clock by 16. So if you changed the crystal to
24.858 KHz you could delete both U2 and U3. (3.579545 MHz divided by 9
divided by 16). Not a prayer of finding a 24.858 KHz crystal (would
actually be a ceramic resonator at that frequency) though. BUT could be a
555 timer tuned to that frequency (CMOS version would be better).

HIS doesn't have the reset pins of the 7493s grounded, would keep them from
counting.

Both schematics have the pinouts/connections to the 74??93s messed up.
Qa is pin 12
Qb is pin 8
Qc is pin 9
Qd is pin 11
It is pin 11, then, that provides the clock for the next stage.

U4 and U5 could be combined into one 74??393.

I'll go back to hiding in the corner now.

On Tue, Nov 8, 2011 at 12:52 AM, Zitt Zitterkopf <zittware@hotmail.com>
wrote:

All,

If you're interested in the re-capture of Dave's Wico Schematics; I've
temporarily posted them there:

http://Pinball-Mods.com/blogs/wp-content/uploads/2011/11/XYPattern.pdf

Still to-do:

1) Determine 7493 wiring vs Dave's schematics.

2) Front Panel board integration - pending Switch Decode.

3) Simulate Opamps for circuit understanding.

4) Power Supply: pending power measurements - if someone will volunteer to
get them.

5) PCB Layout.

6) BOM Generation.

Changes w/regards to Dave's schematics:

A) Decoupling caps for each IC.

B) 0ohm "202 solder shorts" for unconnected pins of TTL gates at U2, U3, U5,
and the "top" of R30 (R3). So they can be reversed if necessary.

C) Passives are likely to have different RefDez.

D) IC Power Supply pins are shown at decoupling grid.

E) "Bussed" Address pins.

F) Unused Gates are "strapped" to a known state.

G) 74xx TTL logic is becoming obsolete. Plan to use 74HC logic or 74LS logic
- haven't decided.

My plan is to have the board manufactured by batchpcb.com as a dual sided
board.

Surface Mount ( yes; I can hear the screams of horror ) as I want to
minimize PCB size - thereby cost.

I'd appreciate any "peer reviews" of the schematic page.

As far as open source for the schematics / pcb; I'm concerned w/regards to
the original owners of the design. IE can't really open source a product I
don't own, can I?
Besides, Dave hasn't really given his blessing to the project given the
source of the schematics are via his work.

John

From: Zitt Zitterkopf <mailto:zittware@hotmail.com>

Sent: Monday, November 07, 2011 9:48 PM

To: vectorlist@vectorlist.org

Subject: Re: VECTOR: Wico XY Pattern Generator - Decoding Switches

David,

Many thanks. I'll put a shorting block to the R3 topside so it can be
disconnected - I'm pretty sure it should be there; even tho TTL generally
defaults to "high" if unconnected.

I found the problem I discovered - It wasn't with the 7490; but all the
7493s. For some reason your pinouts via PADS appear wrong.

http://www.ti.com/lit/ds/symlink/sn7493a.pdf

Fortunately; the QA is right ... but QB/C/D are incorrect . On the 93; they
are not wired as in the 92... 90 and 93 do share the same pinouts tho.

So; are the pin NAMEs right; or are the pin numbers? looks like the same
"mistake" is present on U3/U4/U5.

I'll go ahead and wire up the opamps - thanks for the info.

John

From: David Fish <mailto:dfish_1@comcast.net>

Sent: Monday, November 07, 2011 8:43 PM

To: vectorlist@vectorlist.org

Subject: RE: VECTOR: Wico XY Pattern Generator - Decoding Switches

John,

>>@A-7 on page 1; R3 topside is listed as a NC.

Weird but that's the way it is on my board. Maybe they forgot to add a +5V
jumper.

>> I think you had Q2 and Q3 pins swapped

The pinout for the 7490 is correct QA=12, QB=9, QC=8 and QD=11. The PADS
library part used Q0-Q3 instead of QA-QD.

>> The Power supplies weren't pictured for U14, 15, and 16.

Good catch. They're powered by +/-12V, but that's not shown on the
schematic.

I think the connector issue stems from the fact that they have the two
identical connectors numbered opposite of each other. The main board 8-pin
connector is 1 thru 8 L->R while the switch board is 1->8 R-L. I wonder if I
plugged my cable back in wrong? There's no labels and the keys are symmetric
(stupid). Will look into this more tomorrow.

Dave

From: owner-vectorlist@vectorlist.org
[mailto:owner-vectorlist@vectorlist.org] On Behalf Of Zitt Zitterkopf
Sent: Monday, November 07, 2011 5:37 PM
To: vectorlist@vectorlist.org
Subject: RE: VECTOR: Wico XY Pattern Generator - Decoding Switches

Dave - You rock! Thanks to everyone else too.
I've schematic captured based upon your schematics; Dave - many thanks. The
only peices I haven't captured are the PSU, the 2nd page, and diode switch
matrix.
 
Some questions came up while "re-engineering" the schematics.
 
@A-7 on page 1; R3 topside is listed as a NC... I'm guessing this is
incorrect as why would anyone put a resistor without a second conection?
My Guess is that R3 ties to +5V like the other two (R4, R5).
 
IIRC; something was "off" when I wired U2 @ D-6. I think you had Q2 and Q3
pins swapped. I'll look for sure when I get home.
 
The Power supplies weren't pictured for U14, 15, and 16. These Opamps are
tied to the +12 and -12 rails?
I plan on simulating the opamps to try to gain insight as to what they are
doing.
 
Seems odd that the DAC08s are driven from a non-linear voltage rail. IE V+
is 5V and V- is -12V. I'd have thunk they rails would be symetrical. IE
+/-12V. Maybe the opamps linearize it?
 
Can anyone get me some rail power measurements?
I'm going to try and do away with the transformer and linear regulators in
favor of a more complex (yeah; I know K.I.S.S) PWM psu which puts our all
three rails.
If I knew what the average current was for each rail; a small PWM might be
nice and cheap.
 
I *so* wish this was an opensource hardware project ... I'd so like to
release my PCB and schematics (assuming it works) to the public.
<sigh>
 
John

  _____

From: dfish_1@comcast.net
To: vectorlist@vectorlist.org
Subject: RE: VECTOR: Wico XY Pattern Generator - Decoding Switches
Date: Mon, 7 Nov 2011 17:05:13 -0500

John,

I already have mine apart on my desk. I'm looking at it now. I'm taking lots
of pictures.

Dave

From: owner-vectorlist@vectorlist.org
[mailto:owner-vectorlist@vectorlist.org] On Behalf Of John Robertson
Sent: Monday, November 07, 2011 4:49 PM
To: vectorlist@vectorlist.org
Subject: Re: VECTOR: Wico XY Pattern Generator - Decoding Switches

David Fish wrote:

John,

Before you mirror the schematics let me take a look at them in depth. It was
a looooooong time ago when I drew them.

Unfortunately, I no longer have the schematic source file or access to PADS
schematic cap even if I did. I looked at them online and yes, something
looks screwy about the switch board to main board connector pinout. I'm
thinking there's a reversed connector involved here. I'll let everyone know
what I find.

Dave

I have a working WICO XY Pattern Generator if you need any pictures (either
of you) just let me know and I'll crack it open...

John :-#)#

From: owner-vectorlist@vectorlist.org
[mailto:owner-vectorlist@vectorlist.org] On Behalf Of Mark Shostak
Sent: Monday, November 07, 2011 2:44 PM
To: vectorlist@vectorlist.org
Subject: Re: VECTOR: Wico XY Pattern Generator - Decoding Switches

You can mirror the schematics from ionpool

On Mon, Nov 7, 2011 at 12:43 PM, John Robertson <pinball@telus.net> wrote:

Zitt Zitterkopf wrote:

I'm looking at the schematics for the Wico XY Pattern Generator; and can
seem to figure out how the Front panel PCB connects to the Main Board.

At A-8 on the main schematics page; it shows P3-1-8 as connected to the D
Flip Flops and the A10 of the U7/U8 pattern generating roms.

However, P3 doesn't seem to connect correctly to the "cable" connected to
the front panel board at B-8 on the second page.

It appears that the diode matrix appears to drive set/clear to Dflip flop
U6-A which controls A9 on the ROMs.

But I'm unsure of the encoding given I can figure out how "P3" connects to
the Front panel board.

Anyone have an idea?

John

Do you have a copy of the schematics so I can put them up on TTL? The manual
(such as it is) is there along with images of the Eproms.

ftp://ftp.flippers.com/TTL/TestEquipment/WICO

Thanks,

John :-#)#

-- 
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 
Call (604)872-5757 <tel:%28604%29872-5757>  or Fax 872-2010 (Pinballs,
Jukes, VideoGames)
                 www.flippers.com <http://www.flippers.com/>  
"Old pinballers never die, they just flip out"
 
 
 
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