Propeller ASC schematic:
The Propeller ASC is an Arduino Shield Compatible prototyping system designed to use existing Arduino add-on boards with the Propeller's SPIN language or Propeller Assembly. To stay up to date with the development of this product, please subscribe to this thread at the Parallax forums.
The Propeller chip is a 3.3 volt device, so the ASC uses a series of 2.2K resistors to protect pins P0 through P13. Since some Arduino shields are designed to use 3.3 volts, there are bypass jumpers on the back of the ASC to take the current limiting resistors out of the circuit. These resistors will not interfere with low speed signals such as buttons or switches. However, high speed signals like those of an SPI or I2C device might be attenuated too much for the Propeller to detect. In these cases adding a blob of solder across the appropriate jumper on the back will alleviate this problem.
These add-on cards make use of the Propeller ASCs AUX header on the right side of the board. This header is integrated with a standard Arduino “ICSP” (or “SPI”) header above it, and pins 6 and 7 from the ADC chip below. WARNING: Pins P16 through P23 are not protected! Do not apply above 3.3 volts to these pins!
KVM Adapter Schematic: pasc-kvm.pdf
VGA Adapter Schematic: pasc-vga.pdf