Description
Relisys TR175 II Terminal Control Board 736VA7400F AUX Main Parallel DB25
The Relisys TR175 II Terminal Control Board (part number 736VA7400F, also referenced as A7400AF112) is the main controller PCB for the Relisys TR175 II video display terminal. It handles serial and parallel communications between the terminal and a host computer, routing data through dedicated AUX, Main, and Parallel interface ports on the rear bracket. The board is populated with TTL logic ICs, ROM/RAM DIP chips, and a Signetics SCN2681 Dual UART (DUART) as the primary serial communications controller.
Specifications & What's Included
- Manufacturer: Relisys
- Model: TR175 II
- Board Part Number: 736VA7400F
- Secondary Reference: A7400AF112
- Form Factor: Full-length PCB card with integrated metal bracket
- Primary Controller IC: SCN2681AC1N40 – Signetics/Philips Dual UART (DUART), date code 9348KH (manufactured week 48, 1993)
- Logic ICs: HD74LS163AP (4-bit binary counter), HD74LS273P (octal D flip-flop), 74LS74A, and additional TTL DIP logic ICs
- Rear Bracket Connectors: AUX (DB9), MAIN (DB25), PARALLEL (DB25), Mini-DIN (PS/2-style)
- Country of origin: Korea (marked on PCB)
- Item sold as board only; no cables included
Applications
The Relisys TR175 II was a character-based video display terminal (VDT) from the early-to-mid 1990s, used to connect dumb terminals to minicomputers and Unix/multi-user systems of that era — environments where multiple users shared a central host. Control boards like this one managed serial communication (typically RS-232) between the terminal and the host, as well as parallel output for a locally attached printer. The SCN2681 DUART at the heart of the board was a common and capable dual-channel serial controller widely used in terminals, printers, and embedded controllers of the period. This type of replacement board is sought today by technicians servicing legacy terminal installations, vintage computing collectors, and industrial facilities that still operate older host-based systems requiring character terminal access.
This Relisys TR175 II Terminal Control Board (736VA7400F) has been inspected and is in good condition. The board shows normal handling wear consistent with prior use. The bracket, connectors, and PCB components appear intact with no visible damage. Please view our photo set and contact us if you have any questions. Please note: We have multiple units in stock — yours may not be the one shown in the photos, however, it will be similar in condition and function.
Warranty Information
Additional Information
Brand: |
Relisys |
Model: |
TR175 II |
MPN: |
736VA7400F |
Secondary Model: |
A7400AF112 |
Type: |
Terminal Control Board / PCB Card |
SKU: |
18245 |
Condition: |
Used – Inspected and in Good Condition |
Seller Notes: |
Board only; no cables included. |
Form Factor: |
Card / Module |
Interface Type: |
DB25 Parallel, DB9 AUX Serial, Mini-DIN |
Connector Types: |
DB9 (AUX), DB25 x2 (Main, Parallel), Mini-DIN |
Main Controller IC: |
SCN2681AC1N40 (Dual UART / DUART) |
Compatible With: |
Relisys TR175 II Computer Terminal |
Country/Region of Manufacture: |
Korea |
Condition Notes: |
Relisys TR175 II Terminal Control Board 736VA7400F. Inspected and in good condition. Normal handling wear; board, bracket, and connectors appear intact. No visible damage. |
