Description
3Com EtherLink III 3C509B-TPO ISA 10Mbps Ethernet NIC RJ45 Network Card
The 3Com EtherLink III 3C509B-TPO is a 16-bit ISA Ethernet network interface card running at 10 Mbps over 10Base-T twisted pair. It uses 3Com's Parallel Tasking EZ controller (chip 40-0130-002, also marked AT&T 40-01302), which offloads bus arbitration and data transfer to reduce CPU overhead — a key selling point of the EtherLink III line. The board is dated 1994 and connects to the network through a single RJ45 port on the full-height metal bracket.
Specifications & What's Included
- Manufacturer: 3Com
- Model: 3C509B-TPO
- Product Family: EtherLink III
- Interface: 16-bit ISA bus
- Ethernet Standard: 10Base-T
- Data Rate: 10 Mbps signalling rate
- Network Connector: 1× RJ45 (twisted pair)
- Main Controller Chip: 3Com Parallel Tasking EZ — 40-0130-002 (AT&T 40-01302)
- Memory Chip: Hynix HY6264A LJ-70 (date code 9522B, Korea)
- Copyright / Manufacture Year: 1994
- FCC ID: DF63C509B-TPO
- Form Factor: Full-height ISA card with metal bracket
- Card only — no drivers, cables, or documentation included
Applications
The 3Com EtherLink III 3C509B series was one of the most widely deployed ISA Ethernet cards of the early-to-mid 1990s, found in IBM PC-compatible desktops running DOS, Windows 3.x, Windows 95/98, Novell NetWare, and OS/2. Its Parallel Tasking architecture allowed the card to handle network transfers independently of the host CPU, making it notably faster than simpler ISA NICs of the same era. The -TPO suffix designates the twisted-pair-only variant with a single 10Base-T RJ45 port (some variants also carried a BNC or AUI connector). Driver support was broad and reliable, and the card was a standard choice for small business LANs and educational institutions throughout the mid-1990s. Today these cards are sought by vintage PC enthusiasts and hobbyists maintaining period-correct systems, as well as anyone running legacy ISA-slot machines that still need network access.
This 3Com EtherLink III 3C509B-TPO ISA Ethernet NIC has been inspected and appears to be in good used condition. It was pulled from a working environment where it was previously in use. The PCB is clean with no visible damage, and the RJ45 port and ISA edge connector look intact. The metal bracket shows light surface wear typical of a used card. Please view our photo set and contact us if you have any questions.
Warranty Information
Additional Information
Brand: |
3Com |
Model: |
3C509B-TPO |
MPN: |
3C509B-TPO |
Secondary Model: |
3C509B |
Type: |
Ethernet Network Interface Card (NIC) |
Product Family: |
EtherLink III |
SKU: |
7124 |
Interface: |
ISA (16-bit) |
Data Rate: |
10 Mbps |
Ethernet Standard: |
10Base-T |
Connector Type: |
RJ45 |
Number of Ports: |
1 |
Chipset: |
3Com Parallel Tasking EZ (40-0130-002) |
Compatible OS: |
DOS, Windows 3.x, Windows 95/98, NetWare, OS/2 |
Form Factor: |
ISA Card |
Country/Region of Manufacture: |
Korea |
FCC ID: |
DF63C509B-TPO |
Seller Notes: |
Card only — no drivers, cables, or documentation included. |
Condition Notes: |
This 3Com EtherLink III 3C509B-TPO ISA Ethernet NIC is in good used condition, pulled from a working environment. PCB is clean, RJ45 port and ISA edge connector are intact. Bracket shows light surface wear. Please contact us with any questions. |
California Prop 65 Warning: |
WARNING: This product can expose you to chemicals including lead and lead compounds, and DEHP (a phthalate), which are known to the State of California to cause cancer and birth defects or other reproductive harm. Go to P65Warnings.ca.gov |