This excellent information was rescued from oblivion on the *FlagShip*'s
message base.  Hope it will be helpful to any who need it:
 
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Topic 70        Sun May 29, 1988 
W.DRESCHER                   at 16:03 EDT 
Sub: New C64C bug                            
 
S The new sound chip in the 64C is not compatable with some software, . 
10 message(s) total. 
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Category 1,  Topic 70 
Message 1         Sun May 29, 1988 
W.DRESCHER                   at 16:08 EDT 
  
I have found that the new 64C has a new motherboard and seems to have  a 
different sound chip  . Programs like THE THREE STOOGES and othr ers that 
have digitized sound do not work properly. Has anyone found this problem with 
other games? I really would like to know why Commodore screwed up the 64C.  I 
sold my 'old' 64 for the new style keyboard, only to find I traded 'down' to 
a computer that is not compatable with some of my software.  Wayne 
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Category 1,  Topic 70 
Message 2         Tue May 31, 1988 
D.SCHMOLDT [Dave/SysOp]      at 00:49 EDT 
  
Wayne, 
 
  A member of our user group put an article in the last newsletter comparing 
the chips in the old and new 64s.  They are almost completely different.  He 
wasn't even able to find a SID chip in the 64c, it was disguised so well .... 
or combined with other chips. 
 
  I hadn't heard of any compatibility problems yet.  What does the 64c do (or 
not do) when it runs into digitized sounds?  Does it not even play them, or 
do they just sound strange?  I can't believe Commodore would make any 
modifications to the SID chip addresses and such. 
 
  Dave 
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Category 1,  Topic 70 
Message 3         Tue May 31, 1988 
W.DRESCHER                   at 22:45 EDT 
  
The digitized sound (as in 3 Stooges) is very low in volume compared to the 
music.  I can hardly hear the digitized sound when the music is up a       at 
a good volumn  me.  The   at ruins this particular game. In the h 'hit' and 
'slap' part of the game you need to hear the sound and you can't unless you 
crank the monitor all of the way up. In TEST DRIVE the DI  digitized sound of 
 soung d of the car in the intro is lost....no biggy, but I keep  wondering 
what else I will be missing in the future. Wayne......thanks for the reply, 
it was interesting 
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Category 1,  Topic 70 
Message 4         Wed Jun 01, 1988 
D.SCHMOLDT [Dave/SysOp]      at 01:18 EDT 
  
 C-64 and 64C 
 --Two Different Critters-- 
 by Gary Brinton, Commo-Hawk User Group, Cedar RApids, Iowa 
     According to some articles I've read, I tended to believe that the 64C 
 is little more than a C-64 in a new wrapper.  Although both machines 
 operate the same, there are significant differences in the chips.  Planning 
 on buying one of those $24.95 super kernal chips?  If you have a 64C, 
 forget it.  There may not be a discrete kernal chip in your machine. 
 Certainly it's not the same chip that's in the C-64.  If you're thinking 
 about adding another 6581 SID chip to your 64C to play stereo music with 
 the new SidPack software, forget that too.  There's no 6581 in there.  You 
 can't follow any of the existing instructions on how to alter your machine. 
     Commodore took out many of the cheap (jelly bean) chips like the 74LS 
 series and combined them into big, and probably super expensive chips.  One 
 such is the 251715-01, a 64 pin monster.  They took out so many that they 
 were able to shrink the board width by an inch and 1/2.  Also gone is the 
 6510 microprocessor.  Anyone know where it's buried? 
     What this means from the service angle is that when a large chip goes 
 bad on the 64C, that chip probably isn't available from places like Jameco. 
 You may have to go to Commodore directly.  And, if you've invested $19.95 
 in a Howard Sams diagram for the C-64, it won't work for the 64C.  There 
 isn't any place I know of where you can get a complete diagram of the 64C. 
 Maybe Commodore has it? 
     On the positive side, fewer chips means less time spent hunting down 
 bad ones.  Finding which chips do what, is another matter. 
     The following is a chip list in both machines.  I don't know what each 
 of the 64C chips does, but from the list, you can get an idea of the 
 integration. 
 64C        C-64 
       (Big Chips) 
 6526 (2)         6526 (2)  (Interface) 
 901225-01        901225-01 (Char Rom) 
 --------         901226-01 (Basic Rom) 
 --------         901227-02 (Kernal Rom) 
 --------         906114-01 (PLA)  
 --------         6510 (Micro Processor) 
 --------         6567 (Video) 
 --------         6581 (SID) 
 8500             ----------- 
 8560             ----------- 
 8562             ----------- 
 251715-01        ----------- 
 251913-01        ----------- 
      (Small Chips) 
 7406             7406 
 MC14066          MD14066 
 MN2114           2114L-30L 
 74LS14           -------- 
 74LS508          -------- 
 86458N           -------- 
 8701             -------- 
 8631FU001 (2)    -------- 
 ------           74LS08 
 ------           74LS74 
 ------           74LS139 
 ------           74LS193 
 ------           74LS257 (2) 
 ------           74LS258 
 ------           74LS373 
 ------           74LS629 
 ------           HM4864  (8) (Ram) 
 ------           NE556 
 ------           MC4044P 
   I didn't include the RF modulator chips, because I didn't want to open 
 the boxes. 
   If anyone knows where we can get more information about the 64C, please 
 let me know or print it in the next newsletter.  The articles I've read 
 contain none of the above information. 
 -G Brinton 
 
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Category 1,  Topic 70 
Message 5         Thu Jun 02, 1988 
W.DRESCHER                   at 07:31 EDT 
  
Also, try the game TEHTH FRAME.  The ball sounds like a 'jet' rather than a 
bowling ball going down the lane.  Must be a filter change in  the 64C      
the 64C. Wayne 
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Category 1,  Topic 70 
Message 7         Thu Jun 09, 1988 
W.DRESCHER                   at 07:34 EDT 
  
Well, I fixed my problem, sort of. I found a friend with an old 64 and he 
traded motherboards with me. It took some work, but I put the old board in my 
64C case.  It's too bad I had to suffer just to make my 64 compatable with 
it's own software. I wrote to C= about my (our) problem but I don't really 
expect an answer. Does anyone know what address would be the best to write C= 
about this rticular problem? Maybe they will come out with a 'new' 64 for us 
to buy. They'll probably call it 'Classic Commodore 64'! Wayne 
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Category 1,  Topic 70 
Message 8         Sat Jun 11, 1988 
E.R.FLINN                    at 23:22 EDT 
  
     There is, it seems, yet another complication here.  I have an early 64C, 
and have opened it and found it to have a full-size motherboard, and the 
traditional assortment of 64 chips.  It seems that only the later 64Cs have 
the half-size board and the conglomerated chips.  My 64C is also held 
together with obnoxious Torx screws, but these yielded easily to a tiny allen- 
head driver I had lying around. 
     The claims that the 64C is identical in all internals to the 64, made at 
the time the 64C was first released were, apparently, true at that time.  
<ed> 
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Category 1,  Topic 70 
Message 9         Sun Jun 12, 1988 
W.DRESCHER                   at 23:09 EDT 
  
Yes, I HAD a new 64 with the old  motherboard in it.  It blew out on   on me, 
so I had to bring it back to the store for a new one. I  should hac ve stuck 
with it because I  got a new type motherboard in return I hope C= will fix 
the sound problem Wayne 
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Category 1,  Topic 70 
Message 10        Tue Aug 02, 1988 
W.DRESCHER                   at 07:35 EDT 
  
Well, I heard from Commodore, finally They told me I must have a bad sound 
chip and I should go to the place that I got the computer and get a  new one. 
Well, since I had the  problem I got 2 different ones and they both have the 
same problem The THREE STOOGES game will NOT  work right.  The digitized 
sound can barely be heard. Even many digitized programs from GEnie won't 
work. C= told me they tried their 128's with digitized sound and it processed 
fine.  The sound at the beginning of TEST DRIVE is completely non-existant. 
The bowling ball in TENTH FRAME sounds like an F-15 jet fighter when it rolls 
down the alley. If anyone with a C64C can add to his list (this list) any 
software that doesn't work properly or  even write to C= yourself I would 
appreciate it. Wayne 
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