MFJ MFJ-45B, MFJ-45C User Manual
MFJ-45 A/B/C RAM EXPANSION KIT
1278/1278T) and
boards
expandable
is easily changed
1278B
carefully to ensure
to the
JMP5.
If installing a 512K RAM, then install a jumper on the rear two pins
RAM.
MFJ-45 A/B/C RAM Expansion Kit
The standard RAM configuration for the MFJ-56 (for MFJMFJ-47 (for MFJ-1270, 1270B, or 1274) mailbox memory expansion boards
32K. The memory on the MFJ-56 or MFJ-47 mailbox memory expansion
is expandable to 128K or even 512K. The mailbox memory is
simply by replacing the memory RAM chip. The mailbox RAM
by the user to any size as specified by this instruction
This instruction will reflect all MFJ TNCs from the MFJ-1270 to the MFJ
Multi-Mode Data Controller. Please follow these instructions
proper installation. A proper installation will ensure good operation.
MFJ-1270/1270B/1274 with the MFJ -47
Install the RAM IC on the MFJ-47 expansion board as follows. Please refer
Figure 1 for IC location.
1. Remove all power and cables from the MFJ TNC.
2. Remove the top cover from the MFJ TNC. Remove the jumper from
3. Remove the U424 RAM IC on the memory board and reinstall the new RAM
IC at U424.
4. Re-locate the shorting jumper at J401 header as follows:
Item No. RAM Type J401/JMP19 Position
MFJ-45A 43256LP-10 (32K) The 2 inside most pins (32K)
MFJ-45B 431000LP-10 (128K) The 2 middle pins (128K)
MFJ-45C 8512LP-10 (512K) The 2 outside most pins (512K)
Table 1
NOTE:
J402. This enables the high address line when using a 512K
MFJ-45 A/B/C RAM EXPANSION KIT
Inspect the newly installed RAM IC. Make sure that no IC pins are bent
or not properly inserted in the socket. Replace the jumper
5.
under the IC
removed in step #2, back at JMP5.
PROM MOTHERBOARD
Figure 1
7. Connect all power and cabling to the MFJ TNC.
8. Turn the computer ON, and load your terminal program.
9. Set the power switch on the MFJ TNC to ON. The MFJ TNC should sign- on
to the terminal. If not, then find out why the sign-on message was not
received.
10. Once the MFJ-TNC has signed-on to the terminal, then type the
command, RESET followed by a <CR>. This will enable the firmware to
automatically detect the RAM size change.
If the proper results were not obtained, then take the appropriate steps to
correct the problem. If the proper results were obtained, then congrats, you have
successfully completed the RAM Expansion Kit installation.
MFJ-45 A/B/C RAM EXPANSION KIT
MFJ-1278 with MFJ -56 Installed
Install the RAM IC on the MFJ-56 expansion board as follows. Please refer to
the Figure 2 for IC location.
I. Remove all power and cables from the MFJ-1278.
2. Remove the top cover from the MFJ-1278. Remove the jumper from JMP5.
3. Remove the U424 RAM IC on the memory board and reinstall the new RAM IC at
U424.
4. Re-locate the shorting jumper at J401 header. Please refer to Table I on Page
1 for J401 positioning.
5. Inspect the newly installed RAM IC. Make sur e that no IC pins are bent under
the IC or not properly inserted in the socket.
6. Re-install the jumper removed in step #2, at JMP5.
NOTE: If installing a 512K RAM, then install a jumper on the rear two pins of
J402. This enables the high address line when using a 512K RAM.
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