Page 14 Epson Research and Development
Vancouver Design Center
S1D13505 S5U13505B00C Rev. 1.0 ISA Bus Evaluation Board User Manual
X23A-G-004-05 Issue Date: 01/02/05
When using the header strips to provide the bus interface observe the following:
All I/O signals on the ISA bus card edge must be isolated from the ISA bus (do not plug the card
into a computer). Voltage lines are provided on the header strips.
For the ISA bus, a 22V10 PAL (U4, socketed) is currently used to provide the S1D13505
CS# (pin 4), M/R# (pin 5) and other decode logic signals. This functionality must now be
provided externally. Remove the PAL from its socket to eliminate conflicts resulting from two
different outputs driving the same input. Refer to Table 2-2 Host Bus Selection on page 8 for
connection details.