RE: Asteroids Troubleshooting.

You have to get it to play blind with DMAGO lifted first before you can
tackle the VG side. I socket L6 and have a 74LS42 with pin 1 broken off
(from lifting pin 1 too may times).

Bill

  _____

From: owner-vectorlist@vectorlist.org
[mailto:owner-vectorlist@vectorlist.org] On Behalf Of Kevin Moore
Sent: Sunday, January 10, 2010 4:32 PM
To: vectorlist@vectorlist.org
Subject: Re: VECTOR: Asteroids Troubleshooting.

I just re-read what I wrote. I think I need coffee :)

So it looks like the problem is with the MPU side.

On Sun, Jan 10, 2010 at 4:28 PM, Kevin Moore <talon.k@gmail.com> wrote:

"To determine which section is causing the lock-up, clip and lift pin 10 of
A-9 (Halt). If pin 40 of the MPU no longer has reset pulses, the problem
lies in the program section. "

Forgot to mention I did this, the CPU still resets, so that leads me to the
vector sections.

I isolated pin 1 of L6 to isolate the DMAG0, and it was still resetting.

According to the encyclopedia of Asteroids repair, that means.

"A board that is still resetting has a problem with the MPU and also
possibly the VSM. Check the ROMS, RAM and especially the 74LS245 (or
AM83048) at E2 (E3 on Asteroids)."

So I've replaced the 74ls245, and I've already checked the Roms, and Ram. I
think I can rule out the MPU from the previous removal of pin 10 from A-9
correct?

Which leads me to where I am now. Still trying to figure out what's up with
the VG section.

Kevin

On Sun, Jan 10, 2010 at 3:43 PM, Colin Davies
<colin.w.davies@btopenworld.com> wrote:

Wasn't there a simple way to disable one VG Ready line (or whatever it was)
- So that the CPU would run blind, and you could determine if the VG was
faulty or the CPU side of things ? - I'm sure its in the asteroids trouble
shooting guide on line somewhere....

Cheers, Colin

----- Original Message -----

From: Kevin <mailto:talon.k@gmail.com> Moore

To: vectorlist@vectorlist.org

Sent: Sunday, January 10, 2010 6:29 PM

Subject: VECTOR: Asteroids Troubleshooting.

I'm still trying to learn all this, so please bare with me. Basically I'm
trying to figure out the best way to troubleshoot Asteroids boards. It
shouldn't be as difficult as I'm making it out to be, or is it?

Ok I've got several asteroids boards with the same symtoms.

Test mode comes up good.
No Ram errors, No rom errors.
But under normal game play, get constant reset on pin 40of the CPU

Currently just trying to learn how to trouble shoot 1 board, so I haven't
done all these test on the rest yet.

Have done the following
Verified Rom sigs with Fluke
Verified Ram with Fluke
Verified Bus with Fluke
Have written the following AVG test program to get + sign with Fluke
And well I get the + Sign.

WRITE @ 4000 = FF
   WRITE @ 4001 = A3
   WRITE @ 4002 = 00
   WRITE @ 4003 = 02
   WRITE @ 4004 = FF
   WRITE @ 4005 = 97
   WRITE @ 4006 = 00
   WRITE @ 4007 = 90
   WRITE @ 4008 = 00
   WRITE @ 4009 = A2
   WRITE @ 400A = 00
   WRITE @ 400B = 00
   WRITE @ 400C = 00
   WRITE @ 400D = 90
   WRITE @ 400E = FF
   WRITE @ 400F = 33
   WRITE @ 4010 = 00
   WRITE @ 4011 = E0
   DPY-CONFIRM PLUS PATTERN. CONT#
   DPY-+=EXIT%1#
0: LABEL 0
   WRITE @ 3000 = 00
   IF REG1 = 25 GOTO 2
   GOTO 0
2: LABEL 2
   DPY-##

Went ahead and did sig analysis with the catbox to double check the address
lines, and data lines.
Ran Sig analysis on the VG Address selector,and address generator.

I'm assuming since the sigs are good for those two areas, that the VG
program counter is functioning correctly?

I don't have sigs for the vector generator buffer, I'll have to work on that
since I have several revision boards, some with R2, and some with P2. But
I'm getting out what is going in, so I assume the buffer is ok.

So that leaves the VG Memory data latches? Specifically K7, and J7?

Does that sound about right, or am I just not getting it..

Thanks,

Kevin

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Received on Sun Jan 10 18:10:51 2010