PIC-E 2k serial FRAM modification             1/2000

I recently modified one of my PIC-E units to include a Ramtron
25160 2k serial FRAM IC, yet retain it's ability to run all of
the original programs.
To do this, I mounted the 8 pin FRAM IC on a daughterboard a bit
larger than a stamp and used a 6 pin R/A disconnect header to
tie it in to the PIC-E pcb.  Five of the 6 pins on the connector
are used, they include: +5v, Ground, RAM chip select, RAM clock
and RAM data in / out on a common line.
The PIC-E pcb is viewed from the front (LED end)

FRAM pin                GOES TO:

8       Vcc             PIC-E Via hole on wide, vertical
                        trace, right side of C4.  5v reg.
        ____
7       HOLD            Tied to FRAM Vcc on daughterboard

6       SCK             PIC-E R6 lower lead (ties to B:6)

5       SI              PIC-E R2 upper lead (common w/SO)*

4       GND             PIC-E D2 right lead (PIC-E ground)
        __
3       WP              Tied to FRAM Vcc on daughterboard

2       SO              PIC-E R2 upper lead (ties to A:0)*
        __
1       CS              PIC-E R4 lower lead (ties to B:7)

* Pins 2 & 5 on the daughterboard are tied together (SO/SI)
then with a single wire, tied to (R2 upper lead) A:0.
Vcc and ground can be taken from other places on the PIC-E,
try stay close to the regulator IC to minimumize noise.
I also included a .1 uF bypass cap on the ram pcb between Vcc
and ground.
>>>     Programming is done with the ram pcb disconnected!

To make use of this new hardware, I wrote a packet receive 
program called RAM_RX.ASM which can assembled and programmed
into the modified PIC-E.  Just be sure to unplug the ram board
from it's connector while programming.  This is because the
FRAM shares 2 of the lines used to program the PIC-E and we don't
want to put programming voltage to the FRAM IC.
Afterwards, plug in the FRAM pcb and check the following jumpers.

	JP 1 	OFF
        JP 2    "N" (on 1&2)
	JP 3	ON
	JP 4	ON (off to prgm)
        JP 5    RXD (on 1&2)

Data is out the GPS male 9 pin connector on the PIC-E.
Connect to your Palm hotsynch serial cable with PalmAPRS or a
serial communication program set to 4800,8,1 and apply power.
You should see a sign on message:
TURBO PIC-E packet decoder * N0QBH 1999
Connect the RJ45 jumper from the PIC-E to the radio as usual.
* Audio from the mic connector must be squelched *
Volume should be set low but audible.  If all is well, packets
should be appearing in the view packets screen on the Palmpilot.
As the serial output is 0-5v, I had mixed results when connecting
to a pc.  My old 486 works perfect, my new AMD K6 doesn't.

To use the PIC-E with original software, unplug and remove the
FRAM daughterboard, configure jumpers and program as usual.

73's  Mike Berg  N0QBH