A.02 to A.03 Upgrade list
If you have an A.02 board and want to upgrade to A.03:
To modify an A.02 to A.03 functionality, do the following:
a: voice input circuit (add a few SMT resistors and caps)
1: cut input from voice connector, put a 10K resistor and a 1uF SMT cap
in series.
2: add 2K resistor to isolated ground between the 10K resistor and the
cap.
3. add a 5K resistor to isolated +3V, and a 2K resistor to isolated ground.
b: missing +3V on relays
c: missing clock to daughtercard if (takes place of +12V on HCS2)
d: +5V noconnects on daughtercard now goes to GND, +3V. You can
easily solderblob the signals to the daughtercard connector on the bottom
side.
e: highspeed daughtercard port 16LVT244 driver is now a 16LVT245 and
requires a wire from an unconnected FPGA pad to the right side (pin
1) DIR input. The 16LVT245 driver mounts with pin one to the upper
right near the edge of the board next to the ground test point.
f: +5V regulator changed to higher current version LT1584. This regulator
has the ground and output switched. This is not a required change,
just be sure to put in the required regulator.
g: Added control wire from the FPGA to the daughtercard interface.
HCS_C INDEX
7/2/2005:
HCS_Software (0.04 Alpha)
PC_BOARD A.02 to A.03 update list
Here are the various HCS_C pages.
HCS_C Main Board Block Diagram
HCS_C Bill of Materials parts list HCS_C_schematics
A.03 to A.04 Upgrade list
If you have an A.03 board and want to upgrade to A.04:
a: C ut trace going to input IO enable for the high byte (see photo below)
b: Add wire from FPGA pin 61 to the isolated cut trace
c: PS2 keyboard buffer inputs and outputs are swapped (all shipped boards already have this change, this only applies if you built your own A.03 board)