mark@shorty.CS.WISC.EDU (Mark Spankus) (05/14/89)
Greets!
I have the need to replace a SID chip in a C128. The original chip
is a standard 6581 (12 volts). I have a 6582, but no specs, other than a
statement saying that it is a 9 volt chip. Are these two chips identical
except for the voltages? If so, then it would be no problem to drop the
voltage for the chip & output transistor down a bit.
Any help would be appreciated. Thanks!
-Mark
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Mark Spankus University of Wisconsin - Madison
path: ...!{allegra,heurikon,ihnp4,seismo,ucbvax,uwm-evax}!uwvax!mark
arpa: mark@shorty.cs.wisc.edu
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-fred@cbmvax.UUCP (Fred Bowen) (05/16/89)
In article <7517@spool.cs.wisc.edu> mark@shorty.WISC.EDU (Mark Spankus) writes: > I have the need to replace a SID chip in a C128. The original chip >is a standard 6581 (12 volts). I have a 6582, but no specs, other than a >statement saying that it is a 9 volt chip. Are these two chips identical >except for the voltages? If so, then it would be no problem to drop the >voltage for the chip & output transistor down a bit. You would have to change more than the voltage on pin 28. The filter caps at pins 1-4 should be changed as follows (referencing flat C128 only): C83 22000pf for 6582 470pf for 6581 C82 2200pf for 6582 1800pf for 6581 and pin 27 audio out: R11 remove for 6582 1Kohm for 6581 I'd recommend you try and find the proper replacement part. Normal disclaimer: hack at your own risk. -- -- Fred Bowen uucp: {uunet|rutgers|pyramid}!cbmvax!fred arpa: cbmvax!fred@uunet.uu.net tele: 215 431-9100 Commodore Electronics, Ltd., 1200 Wilson Drive, West Chester, PA, 19380