@6042.ADF EtherLink/MC Ethernet Adapter
3C523X.EXE V3.3 EtherDisk for ELMC/TP (8193-04)
3C523N.EXE EtherDisk, 3C523 family w/latest patches, V3.4.
LANscope.rar LAN Datascope For Ethernet
Intel 82586 datasheet
3c523 Technical Reference
3C523 Etherlink/MC TP
Setting Jumpers on EtherLink/MC TP Adapter
Late 3C523 Etherlink/MC
Older versions not compatible with 486+
LAN Datascope For Ethernet
3C523 ADF Sections
J1 System Configuration Jumper
J1 allows the adapter to be enabled even though the host
system's Configuration RAM contains no entry for it. The
only time J1 should be moved from "A" to "B" is if the
adapter has been installed in a computer that has no
floppy disk drives and there as no provision for
temporarily installing one to run the configuration
utility on the system's reference diskette.
When the jumper is installed in position "B", the Card
Enable feature of POS is overridden so that the adapter's
Start ROM program can be accessed during the ROM scan that
occurs during the power-up sequence. This Card Enable
override is necessary when the host system's configuration
RAM doesn't contain an entry for the adapter. Without the
jumper, if there isn't an entry in the system's CMOS RAM
for the adapter, the system will leave the adapter in the
disabled state and its ROM won't be found during the ROM
When using the adapter in this specialized configuration,
care must be taken that no bus conflicts will occur
because the adapter will be enabled before it is
configured. The power-up default configuration for the
adapter is as follows: I/O base address = 0300H, memory
base address =0C0000H, interrupt level = 12 and the
on-board transceiver will be selected.
For general operation, the jumper should be in position
Jumpers on EtherLink/MC TP Adapter
a. Use a test
device to verify the impedance of your cable from wiring
closet to station.
b. Choose setting
closest to that characteristic impedance.
Default Setting: 100 ohms
Alternative Settings: 75 ohms, 150 ohms
THRESHOLD, LINK BEAT, EQUALIZATION, TRANSMIT
LEVEL, and DC SIGNAL jumpers,
refer to Table 1.
Table 1. Jumper Settings for 10BASE-T and
AT&T StarLAN 10,
Systems BULL Hub 10
Late 3C523 Etherlink/MC
1E RPL socket
6B,7B 3Com 6408-01
7E NS DP8391AV
8E Motorola MC10116L
LP1 Neon Lamp
P2 AUI port
P3 BNC port
Y1 20.00000 MHz osc
Y3 16 MHz osc
I found two of these in a 3172 Interconnect
Controller. Marked "(C) 1990 3Com" on the front.
Versions not Compatible with 486+
The "old" 3C523 have a copyright date of
1987 on them and will only work properly in a 286 or
386. From my experiences, it will only let the first 8MB
RAM be usable no matter how much RAM you have
installed. The newer revision will have a 1990 or
1991 date on it.
Fact is: some series of the older
Ethernet/MC have a microcode incompatible with
486-processors. (Bus signaling most likely - haven't
tested that in depth)
Symptom: they worked fine as long as they
were used in Mod. 70/80 - but when the customer swapped
them to the new bought 76/77 they went belly up and did
not even pass the DOS-based diags test.
These are older ones produced before 1990
- but ironically not all old cards are automatically
affected. There was a diagnostic program available from
3COM (I think it came with the revised E/MC) which
checks the microcode level and warns for possible
incompatibilities. In addition some of the setup / diags
and driver software had a problem with later OS-versions
(did not run properly under PC-DOS 4.x and above due to
"version conflict"). Whatever.
Component Differences, Old vs.
>Is that a 3C523? ISTR that those (or most of them,
anyway) wouldn't work properly in anything than a
The original 3C-523 has a limitation - the later ones
(3C-523B) hasn't. Roughly the two can be differed by
looking on the board:
Round "transformer", many "through-hole"
chips and "classical" resistors, long DIL "i" (Intel)
82586 MCU, "(C) 1987 3Com" at frontside.
Square "3Com" transformer, mainly SMD chips with
square QFP "i" Intel 82586 MCU, "(C) 1991 3Com" along
The old one will most likely not run with anything
bigger than a 386DX - the new one hasn't got this
problem. Works with 486 and Pentium. Both cards have the
same card-ID and use the same ADF, so you cannot tell
which is which by the ID only.
LAN Datascope For Ethernet
This Program was authored by Keith Shortt in IBM Toronto
as a LAN Development Tool and is being distributed as an
interim tool for problem determination on Ethernet Local
Area Networks. It supports only the 3COM PS/2 ETHERNET
Adapter #3C523 available from 3COM distributors and runs
under DOS 3.1 or higher.
The 3COM adapter is also known as the ETHERLINK/MC
Adapter and includes the microchannel adapter and a
diskette containing diagnostics, the adapter description
file for configuring the PS/2, and a software driver
which is not needed with this program. Note that this
adapter provides both on-board transceiver and external
The Datascope program and adapter operate on PS/2
microchannel systems including the IBM P70. Follow the
instructions included with the 3COM adapter to install
the adapter, configure the PS/2, and test the adapter.
The 3+ driver is not needed for this application.
The two files included with this package are SCOPE_EN
EXEBIN and SCOPE_EN HLP which provide the program and
documentation to trace and display traffic on an
Ethernet LAN. Note that an adapter is not required to
display and interpret trace files previously taken.
SCOPE_EN EXEBIN should be downloaded in binary form.
6042 3Com EtherLink/MC Ethernet Adapter
Disabled if you are not using adapter and
enabling it causes a conflict with another device.
Adapter Enabled >, Adapter Disabled
I/O Address Range
Addresses used by EtherLink/MC. Addresses
cannot be used by another installed device
300 to 307 ">, 1300 to 1307, 2300 to
2307, 3300 to 3307
Interrupt level used by EtherLink/MC. This
can be shared, but you may be able to improve
performance by selecting a level that is not used by any
<" Channel 3 " (
INT 3)>, 7, 9, 12
Packet Buffer RAM Address
RAM and ROM addresses used by
EtherLink/MC. These cannot be used by any other
installed device. Each range is 16K bytes of RAM
followed by 8K bytes of ROM
<" 0C0000 to
0C5FFF " >, 0D0000 to 0D5FFF , 0D8000 to
On-Board used for BNC or RJ45 (EL/MC
TP only). External used with AUI.
<" On-Board (BNC
or RJ45) ">, External (AUI)
The computer containing the EtherLink/MC
adapter to be tested must be running DOS. If this
computer is an operating server, notify all users of the
server to save their work and log out from the
network. The diagnostic program disrupts the normal
operation of the server, and work that is not saved may be
lost. The diagnostic tests do not function properly
if you run them after booting your system with NetBIOS
installed. Please start your computer with a standard boot
diskette that does not contain a network driver.
If Group 3 tests are running while computer is connected
to an active network, intermittent packet exchange
failures may occur before the tests are done.
These failures can be avoided by running Group 3 tests
on an inactive network in which only the computer being
tested and the echo server are connected.
ELMC Fails Diagnostics
If the diagnostic tests fail, the adapter may not be
defective. Check the following:
1. Make sure adapter is completely seated in
2. Inspect all cables and connections.
3. For Group 2 tests, make sure adapter is
securely connected to a loopback plug (coax version
only) or to a properly cabled inactive network.
4. For Group 3 tests, make sure adapter is
securely connected to a properly cabled inactive network
and that an echo server is set up on the network.
5. Make sure that no settings conflict with any
other peripheral or software program (such as 3Com's
Extended Memory Manager) installed in computer.
For a list of system resources commonly used by other
peripherals, select "Additional Adapter Information"
from the main menu, then "System Resources" from the
6. Make sure that the transceiver type selected is
7. Running tests while connected to an active
network can cause intermittent failures. These
failures can be avoided by using an inactive network on
which only the computer being tested (and an echo server
if running the Group 3 tests) is connected.
8. For an EtherLink/MC TP adapter, check LEDs on
back-plate. Yellow (ACT) LED is on when there is
data transmission activity on adapter. This light
will go on during Group 2 and Group 3 tests. Green (LNK)
LED will be on when there is a correct connection
between adapter and hub. If link pulse jumper is
OFF, the green LED is on, connection or not.
9. If you have installed an EtherLink/MC TP
adapter, make sure that the settings for the following
jumpers are correctly configured for the hub:
For information on setting
these jumpers, select "Additional Adapter Information"
from the main menu, then "Twisted-pair Options" from
10. Computer slot may be defective. Install adapter in
another slot and run tests again.
11. Computer that adapter is installed may be
defective. Install adapter in known functioning computer
and re-run tests.
12. Loopback plug may be defective. Try a
different loopback plug.
13. Replace failed adapter with known good EL/MC
adapter with same jumper settings. If second
EL/MC adapter fails, something is wrong with test
environment, not with adapter.