Some complete fleXYcad-style circuits should eventually appear here, for transfer to a Newton Notepad

• opto A/D circuit     original stripboard version      uses PIC 12F675
• opto circuit    same circuit, different layout, for making a pcb
• WiFi-detector   uses PIC 12F675
• amplifier    uses dual 741 op-amp for capturing heartbeats, for Newton and PC version
• a/d converter    used in the Newton-version heartbeat project
• digital controller    used in the Newton-version heartbeat project. 2 x PICs + 6116 RAM chip
• a/d converter    used in the PC-version heartbeat project, without RAM storage