Jumper Settings

• JP1: If opened, disables the Power-Up Reset (Default: Closed).
• JP2: Chooses whether Agnus pin 59 is connected to A19 (Middle + Bottom, Default) or A23 (Middle + Top). This has to do with the trapdoor memory being mapped to Chip or Fast RAM, but more info is needed.
• JP3: Swaps upper and lower RAM banks (Default: Horizontal).
• JP4A/B: Bypasses U32 for 512K system (Default: Open).
• JP7A: Allows connecting the /EXTICK signal to pin 32 of the Trapdoor Connector (Middle + Right). Can also be used to permanently grounds /EXTICK (Middle + Left), no idea why (Default: Fully open).
• JP7B: Chooses the timer source for the Odd CIA (U7): /VSYNC (Moddle + Left, Default) or /EXTICK (Middle + Right).
• JP8: Allows switching the Light Pen Button from the Joystick Port (Middle + Left, Default) to the Mouse Port (Middle + Right).
• JP9: If closed, disables the internal Real-Time Clock (Default: Open).
• JP10A: If opened, the AUDIN (Audio In) signal from pin 18 of the Serial Port does not get mixed into the right audio channel.
• JP10B: If opened, the AUDOUT (Audio Out, essentially the left audio channel) signal is disconnected from pin 11 of the Serial Port.
• JP11: Chooses whether the Composite Sync signal going to pin 10 of the Video connector is the raw BLANK signal (Middle + Bottom, Default) or a version of it that gets amplified by the Video Hybrid (Middle + Top).