Re: c64 breadbin vs c64c

From: Mario Kienspergher <contact_at_kinzi.net>
Date: Wed, 18 Oct 2023 17:16:47 +0200
Message-ID: <c6b3e7ff-2b35-414a-87de-ae289e94e39c_at_kinzi.net>
The 252535-01 works correctly as 251715-01 in pre Rev.B boards since Pin 
18 (IIRC) signals the 252535-01 to disable internal Color RAM and enable 
/CS for Color RAM on the needed pin.


Am 18.10.23 um 15:55 schrieb Pasi Lassila:
> On Mon, 16 Oct 2023 at 21:27, Gerrit Heitsch 
> <gerrit_at_laosinh.s.bawue.de> wrote:
>
>     On 10/16/23 20:10, Jim Brain wrote:
>     > On 10/16/2023 12:51 PM, Gerrit Heitsch wrote:
>     >> On 10/16/23 19:28, didier_at_aida.org wrote:
>     >>> I 'll try to find a spare PLA, Video chip and SID...
>     >>
>     >> There are 2 different kinds of the 64pin PLA:
>     >>
>     >> 251715-01  PLA C64C (64pin)
>     >> 252535-01  PLA C64C (64pin, integ. Color RAM)
>     >>
>     >> The first one is easier to find, but doesn't fit your board.
>     >>
>     >> But they are both CMOS, stay cool and hardly ever go bad.
>     >
>     > Can you use the Color RAM version in the non COlor RAM needed
>     board, if
>     > that makes sense?
>
>     Never tried it since I never had one go bad. Maybe because they
>     were not
>     made by MOS but by well known semicondutor makers like SHARP or
>     YAMAHA
>     (*). Also when looking around, I found the version without color RAM
>     easier to find.
>
>     (*) The part numbers besides the Commodore part numbers gave that
>     away:
>     YM3535 and LH5062B on my 251715-01 and on a 252535-01 SHARP even
>     printed
>     their logo.
>
>       Gerrit
>
>
> Pinout looks the same except pin 17 is used for external colour RAM 
> chip select signal.
>
> -Pasi
Received on 2023-10-18 18:00:08

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