Hi there! Here is a little ugly ASCII schematic for inserting a 8x-kernel and 8x-Module switch inside the kernel socket of a c-64. This one does not switch between "pairs" of Kernals/Module-Roms, but you can select each module and each kernel separately. After every resistor (10 kOhm) you must actually insert a switch going to GND. This is not in the schematic ASCII drawing due to lack of space. It is actually meant to look like this: 컴컴컴컴컴컫컴컴컴컴컴� 5 Volt line � 憫� 쿝� Resistor � � 읓� � Switch __/ x컴컴컴> to any chip-input (of the 74LS157) � � 컴컨컴� 컴� GND � So you can see, there is a switch connected to each end of every resistor. You also need a switch between Pin9/Cart port and GND. This is not on the schematic, for the same reason (i.e. lack of space). But it is rather obvious. You need the following parts: 6* R=10 k Ohm (used as pullup resistor) 1* 271001 Eprom 1* TTL 74LS157 7* Switch The memory map: 0000-ffff: 8 module ROMs 10000-1ffff: 8 kernal ROMs The "x" before a line symbolizes a pin going to the kernal socket. Pin 3 (A15) of the Eprom is not connected to Pin 27 of the Eprom in any way, although the schematic almost looks like it. Sorry for the ugly ascii work. (Still easier than installing Eagle and drawing... :-) Happy soldering! ATT / L Pin11 Mod.p = !CS2 旼컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컫컴�>to Pin11 Cart.Port � � � 271001 � � 旼컴컴컴컴컴컴컴컴컴컴컴커 � � 旼� 1 쳐� +5V � � 쳐탠컴컴컴컴컴컴컴컴컫컴컴컵컵컴컴컴컴컴컴쩡컫컴컴탠컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴쩡컫컴쩡컴컫컴컫 5 Volt � 읕� � 쳐� � � � � � � � � � 旼� 2 � 쳐� � � � � 憫왯좆 憫� 憫� 읕컴컴컴캑 � A16 +5V쳐컴컴탠� 憫왯좆 � � � 납 � � � � � 읕� � 쳐� � 납 � � To A14 Eprom � 쿝납R� 쿝� 쿝� 旼� 3 � 쳐� 쿝납R� � 旼컴컴컴컴컴컴컴컴컴컴컴컴� � 읓牡쬔 읓� 읓� 쳐탠컴컴커 A15 � � � 旼컴컵컵탠탠컴탠컴� 旼컴컴컴컴컴컴컴컴컴� 읕탠컵컴탠커 � � 읕� � � 쳐� � 읓牡쬔 � 旼� 1 16 쳐� � � � � � � 旼� 4 � � 쳐� � � � 쳐컴컴� � � 쳐� � � � � � Kernal 쳐탠커 � � A14� 쳐컴컴켸 � � � 2* 읕� 74LS 쳐� � � � � � Socket 읕� � � � 쳐� � � � P.11旼� 2 157 15 쳐� � � � � � 旼� � � +5V� 쳐� � � 읕컴컴� � � 쳐� � � � � � x1컴컴컴컴� � � � x A13� 쳐컴컴컴� � � 읕� 쳐� � � � � � � 읕� � 읕컴컴� 쳐� � � � CSold旼� 3 14 쳐� � � � � � � 旼� � 읕컴컴컴컴컴탠쩡컴� � � � 旼컴컴컴� � � 쳐탠켸 � � � � x2컴컴컴컴� � � x컴컴컵캑 � � � � � 읕� 쳐� � � � � � 읕� � 쳐� � � � � � CSnew旼� 4 13 쳐� � � � � � 旼� � 쳐� � � 旼탠컵컴탠컴컴컴� � � 쳐탠컴컴� � � � x3컴컴컴컴� � � x컴컴컵캑 � � � � � � 읕� 쳐� � � � � 읕� � 쳐� � � � � � � 旼� 5 12 쳐� � � � � 旼� � A12 쳐� � � � � 읕컵컴컴컴캑 � � 쳐탠컴컴컴켸 � � x4컴컴컴컴� � 읕컴컴컴컴컴컴컴x 旼탠� � � � � � 읕� 쳐� � � � 읕� � 쳐� 읕커� � � � 旼� 6 11 쳐� � � � 旼� � 쳐� 납 � 읕컴컴탠컴컴컴� � � 쳐탠컴컴컴컴켸 � x5컴컴컴컴� � 旼컴컴컴x � � 쳐컴� 납 � � 읕� 쳐� � � 읕� � � 쳐� OE� 납 � � 旼� 7 10 쳐� � � 旼� � � 쳐� � 읖컴탠컴컴컴탠컴컴컴� � � 쳐탠컴컴컴컴컴컴켸 x6컴컴컴컴� � � x컴컵컵캑 쳐컴탠켸 � 읕� 쳐� � 읕� � � 쳐� � � � 旼� 8 9 쳐� � 旼� � � 쳐� CS� � � 旼� � � 첼� x7컴컴컴컴� � � x컴켸 � 쳐컴� � � � 읕� 쳐冒� 읕� � 쳐� � � � 읕컴컴컴컴컴컴컴컴컴� 납 旼� � 쳐� � � � 납 x8컴컴컴컴� � � x17컴컵캑 읕컴컴컴컴컵컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴冒 읕� � 쳐� � � To A13 Eprom � 旼� � 쳐� � � � x9컴컴컴컴� � � x16컴컵캑 � � � 읕� � 쳐� � � � 旼� � 쳐� � � � x10컴컴컴캑 � � x15컴컵캑 � � � 읕� � 쳐� � � � 旼� � 쳐� � � � x11컴컴컴캑 � � x14컴컵캑 � � � 읕� � 쳐� � � � 旼� � 쳐� � � GND � GND x12컴컴컴캑 � � x13컴컵캑 � � � � 읕� � 쳐� � � � � 읕컴컴컴컴컵컴컴컴컴컴컴켸 � � � � � � � � � � !CS from Kernalsocket ("CSold") � � � � 읕컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴켸 � � � � � � GND � � 읕컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴좔컴컴컴컴컴컴컴컴컴컴컴컴컴� GND