Re: 2114's ->RE: BattleZone probs....

I suspect that there are timing characteristics for various
manufacturers of the 2114's that must be taken into consideration when
replacing the damn things. This reminds me of one of the Galaga cures
from back in the 80's, it warned that you HAD TO use a TI 74LSXX(I
forget the exact chip) in the clock circuit otherwise the game is not
reliable! Other manufacturers apparently had slightly different timing
and would be off enough to cause intermittant problems. I would thus
suggest that someone research who built the FIRST 2114 and check the
specs against ones we are looking to buy as replacements. The designers
of the games would use the specs from the original device as part of the
design...

John :-#)#

Todd Miller wrote:
>
> I also experienced similar problems with 2114's on several of my Sega
> G08 X-Y boards.
> I had bought a bunch from BGI (2114AL- 2 ?) and since they were faster I
> assumed they
> should perform just as well, no such luck . I also tried 2148's with no
> luck. I ended up
> talking some older 2114's off of another PCB to solve the problem. Why
> is this ? can
> anyone explain ? Clay, didn't you discuss at one time making a simple
> 2114 tester ?
>
> Todd Miller, IT Operations Dept.
> Ron Weber and Associates
> 103 E. State Street, Mason City, IA 50401
> (515)423-4293/(515)423-4594 FAX
> http://www.telethinking.com
>
> -----Original Message-----
> From: Matt Rossiter - Verio Southern California
> [SMTP:matt@rossiters.com]
> Sent: Sunday, January 17, 1999 10:43 PM
> To: vectorlist@mcfeeley.cc.utexas.edu
> Subject: Re: BattleZone probs....
>
> I had a problem just like this about a year ago. Mine was
> complaing that
> one of the 2114s was bad. So I replaced it, then it complained
> that
> another one was bad - and so on. ~augh~. Well it turns out
> that
> Battlezone (or other 80's games that use 2114 chips) will choke
> on newer
> versions of 2114 chips. I can't remember that exact part number
> - but I
> know it was an Intel. The newer ones are faster and do cause
> problems on
> Battlezones.
>
> To make a long story short, I put in an older version and
> everything
> worked perfectly.
>
> Hope that helps.
>
> Matt
>
> _____________________________________________________________________
>
> On Mon, 18 Jan 1999, Peter Pachla wrote:
>
> > Been having another crack at fixing my BattleZone tonight and
> I'm somewhat
> > confused....
> >
> > The last time I looked at it (a few months back) the self-test
> routine told me
> > that one of the ROMs was bad, now it's telling me that
> (another) one of the RAM
> > chips has failed.
> >
> > I can't understand why this would be. I've tested all of the
> TTL on the board
> > with a logic comparator and none of the chips appear bad (I
> had to replace
> > three before) so it shouldn't be a memory decoding problem.
> >
> > Now, before I got the machine my friend who owned it then had
> to repair the
> > Audio/Reg II board since the 2N3055 on it packed up. He
> replaced it with a
> > fixed voltage regulator (modifying the circuit appropriately)
> and I've noticed
> > that the voltage reaching the analogue vector generator board
> is a little on
> > the low side at 4.73V, just outside normal TTL power specs.
> >
> > I'm assuming that this is causing my problems?
> >
> > My friend couldn't get a 2N3055 which is why he used a voltage
> regulator
> > instead. Are 2N3055s still available, if not can anyone
> suggest a suitable
> > alternative as I intend to reverse his mods and put things
> back the way they
> > should be?
> >
> >
> > Back to tonight's "Voyager" (we're only about 18 months behind
> you guys on this
> > side of the pond).
> >
> >
> > TTFN - Pete.
> >
> > --
> > Peter Pachla: Computer Hardware & Software Engineer,
> > Sound Engineer,
> > Arcade Machines Collector,
> > Obsolete Computer\Games Console Collector,
> > Barman,
> > & General Fun Guy....
> >
> > E-Mail: peter.pachla@virgin.net (primary account)
> > peter.pachla@vectrex.freeserve.co.uk
> > peter.pachla@wintermute.free-online.co.uk
> > --
> >
> >

-- 
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