Re: VECTOR: battlezone

i am not certain of anything at this point.
the state machine is not working. i am not getting OP signals from the address decoder or dvx and dvy signals from the data shifter which can be ultimately traced back to the address lines.
in test mode i get a variation of a square wave on all the address lines, but in normal mode 4 address lines don't look right. i hate to keep coming back to the address lines, but 3 of the lines go to the decoder and the output from the decoders don't change. it seems the thing to do is change the decoder chips, but the 3 lines feed 4 chips. i just don't see all the chips going bad at the same time. the suspect lines are a6, a10, a11, a13. rom0 thru rom5 don't change, ram doesn't change. neither does wdclr, vgrst, vggo. i just don't get it. 6502 is good, the buffers i am convinced are good, but the decoder doesn't work.
  ----- Original Message ----- 
  From: Joe 
  To: [email protected] 
  Sent: Friday, December 17, 2004 2:26 AM
  Subject: RE: VECTOR: battlezone


  Are you certain it's the program side that's tripping the watchdog and not the VSM? That's your first course of action - disable the VSM.

   


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  From: [email protected] [mailto:[email protected]] On Behalf Of dorian
  Sent: Thursday, December 16, 2004 11:21 PM
  To: vectorlist
  Subject: VECTOR: battlezone

   

  i changed the ram's and no luck. 

  i guess i'll change the 139's. 

  but three chips going bad at the same time?