
To install the modified firmware, the AM950.bin file must first be
programmed into a 27c256 32KB EPROM chip. This can be either a UV-erasable
part or a one-time programmable part, as long as it meets (or exceeds)
the 150ns access time specification of the original part and has the same
pin-out.

If a UV-erasable part is used, a sticker should be placed over the
porthole in the center of the chip to prevent UV light from resetting
any of the bits after they've been programmed. (This is unlikely to
occur unless you leave the chips sitting out in direct sunlight, but
better safe than sorry.)

Once the chip has been programmed, it can be installed in the radio
using the following steps:

1) Remove the top and bottom covers of the radio. Note: built-in speaker
   attached to the top cover panel has a cable that plugs into the
   radio. Do not jerk the top cover away as this may damage the cable.
   Remove the top cover slowly and unplug the connector, then put the
   covers aside.

2) Locate the two screws on either side of the front panel.

3) Remove the top screw on either side, and loosen the bottom screws.

4) Carefully fold the face of the radio down, exposing the digital unit.

5) Locate the existing firmware chip, IC18, which is to the right of the
   lithium backup battery.

6) Using a chip puller, carefully remove the existing chip from its socket.
   You may want to keep a thumb or finger pressed against the digital unit
   just above the IC socket to keep the digital unit board from flexing.
   (If you don't have a chip puller, a small screwdriver can be used to
   pry the chip loose.) Once removed, put the chip aside and save it.
   You may also use your EPROM programmer to dump its contents to make
   an archival backup of the original firmware.

7) Carefully insert the replacement chip, with the notched end pointing
   down.

8) Fold the face of the radio back up into place and re-insert/re-tighten
   the side screws to secure it

9) Replace the top and bottom covers

10) Re-connect the DSP interface cables

11) OPTIONAL: press and hold the A=B button while powering on the radio
    to reset the CPU.

12) Enjoy your newly upgraded radio
