Dragon's Lair Fans - Arcade Lifestyle
General Chat => Technical Area => Topic started by: vernimark on October 22, 2012, 08:06:35 AM
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Hi all,
I was repairing BAZOOKA PCB, some final issues because 90% of the game was working.
THen I did a test saturday night before an appointment with my girlfriend. Probably an "upside-down" desire passed through my mind and I plugged that PCB in the wrong way connecting 36vac directly on TTLs
I could see chips exploding like pop corns haha
afret 2 very long days I changed more or less 50% of all chips on board!!
anyway I need your help because this game needs 74189 RAMs and I don't know where to find them.
On ebay I bought 74189 from TELEC without any speification and they sent me 74LS189AN and not 75LS189N. It seems these models are not ompatible.
just for testing I'm using now 7489 bcause I can see this RAMs have the same pinout but some signals are loo low...
do you know why N and AN are not compatible?
do you know where to buy 74LS189N rams?
regards
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Do you have a pic of the Bazooka game? I bought one in the US from PSE and wonder if its the same.
(Cant help with the hardware issue though, sorry.
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my bazooka is a bootleg. One board with a small sound board, soon pictures
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Got the following answer from Twisty Arcade when asking for the rams you need.
"I have 74S189 and 7489 which are both compatible. "
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Got the following answer from Twisty Arcade when asking for the rams you need.
"I have 74S189 and 7489 which are both compatible. "
mmm... 7489 are not 3state but I don't know which kind of side effects can produce...
Twisty Arcade web site seems to be not available at the moment.
I could find them at www.jameco.com
not so cheap...
vernimark
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Its this website. Just email the guy for advice.
http://www.twistywristarcade.com/
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twisty: 3.78usd for each 7489
jameco 2.75usd for each 74189N
I think I'll use this second option.
Thank you anyway for the info, I didn't know www.twistywristarcade.com, very interesting!
vernimark