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Step-by-step guide for installing the Multiterminal Interface Board into the computer's card cage assembly.
Details on setting the DIP switch and ensuring jumpers are in place for proper interface operation.
Instructions for connecting various terminal types using RS-232 cables and optional modem adapters.
Commands to confirm the correct installation and basic functionality of the Multiterminal Interface.
Procedures to enable specific terminals (tty01-tty06) for use within the TRS-XENIX operating system.
Steps for properly logging out and disconnecting a terminal from the main computer system.
Outlines the customer's duties regarding equipment operation, environment, and software use.
Details Radio Shack's limited warranties for hardware and software, including purchase conditions and exclusions.
Specifies limitations on Radio Shack's liability for indirect, special, or consequential damages from product use.
Defines the non-exclusive license granted for Radio Shack software, including usage and reproduction restrictions.
Clarifies the terms under which the warranty provisions apply to sales and licensing transactions.
Information on specific legal rights granted to customers that may vary from state to state.
The Multiterminal Interface is an expansion board designed for use with Radio Shack's Model 16B or upgraded Model 12 computers. Its primary function is to enable the connection of up to three additional terminals to a single computer system, allowing multiple users to share a common hard disk drive. This capability transforms a standalone computer into a multi-user system, enhancing its utility in environments where shared resources and concurrent access are beneficial. The interface is specifically designed to operate with the TRS-XENIX operating system, version 01.03.00, which is a crucial software requirement for its proper functioning. Users must ensure their system is running this specific version of TRS-XENIX, either by upgrading an existing 01.01.00 or 01.02.00 system with a software update diskette (Catalog No. 700-2066) or by acquiring the TRS-XENIX Version 01.03.00 Core System (Catalog No. 700-2052) if they do not already possess it.
The core function of the Multiterminal Interface is to provide the necessary hardware connections and logical pathways for multiple terminals to interact with a central computer. By installing this board, the computer gains the ability to manage input and output from several independent workstations simultaneously. This is particularly advantageous for tasks that require data sharing, collaborative work, or simply extending the reach of a single powerful computer to multiple users without the need for separate, fully equipped machines. The interface essentially acts as a multiplexer, allowing the central processing unit (CPU) and hard disk to be accessed by various terminals as if they were directly connected. The system's architecture, as depicted in the installation diagrams, shows the Multiterminal Interface residing within the card cage assembly of the Model 16B or upgraded Model 12, alongside other critical components like the 68000 CPU, 16-Bit Memory, Option boards, Video Board, and Hard Disk. This integration ensures seamless communication and resource allocation across the connected terminals. The board includes multiple connectors (J1, J2, J3) for attaching remote terminals, supplementing the computer's existing serial channels (A and B).
Setting up and using multiple terminals with the Multiterminal Interface involves several key steps, primarily managed through the TRS-XENIX operating system. The system is pre-programmed to accommodate a wide range of terminal types, but it requires explicit configuration to recognize the specific characteristics and capabilities of each connected terminal. The console is initially configured for two DT-1 terminals, which TRS-XENIX identifies as "Adds25" terminal types, expecting them to be set to the DT-1's Adds25 emulation mode. This information is stored in the /etc/ttytype file. If connecting a DT-1, users can follow direct connection instructions. However, for other terminal types, users must inform TRS-XENIX by editing the /etc/ttytype file to include the appropriate terminal name from a predefined list. This list, stored in the /etc/termcap file, contains names and codes for commonly used terminals such as VT 100 (vt100), VT 52 (vt52), ADM 3a (adm3a), ADM 5 (adm5), Televideo 910 (tvi910), and ADDS 25 (adds25).
Connecting a terminal to the computer involves selecting the correct connector. For Serial Channel A or B, an RS-232 cable (Cat. No. 26-4403) and a null modem adapter (Cat. No. 26-1496) are required for each terminal. The RS-232 cable connects to the terminal's RS-232 jack, and the null modem adapter connects to the computer's Serial Channel A or B. For terminals connecting to the Multiterminal Interface PCB's dedicated connectors (J1, J2, J3), only the RS-232 cable assembly is needed, as a null modem adapter is not required for these ports (ports 4, 5, and 6).
Once physically connected, terminals must be enabled within the TRS-XENIX system. This is done by typing specific commands at the console (from root). For Serial Channel A, the command is enable tty01 <ENTER>. For Serial Channel B, it's enable tty02 <ENTER>. For terminals connected to the Multiterminal Interface PCB, the commands are enable tty04 <ENTER> (for J1), enable tty05 <ENTER> (for J2), or enable tty06 <ENTER> (for J3). Before enabling, users can verify the installation by typing disable tty0X (enter) (e.g., disable tty04), which should result in no response or a message indicating the tty is already disabled or /etc/ttys not updated, confirming the system recognizes the port. Port 3 is explicitly noted as not being used. The system also provides a mechanism to disable terminals when they need to be disconnected, ensuring proper system management. This involves ensuring the terminal is not logged in and then typing disable tty0X corresponding to the connected port.
The Multiterminal Interface is designed for straightforward installation and minimal ongoing maintenance, primarily focusing on proper initial setup and software configuration. The physical installation involves opening the computer's rear cover, removing card holding brackets from the card cage, setting a DIP switch (S1 to ON, S2-S8 to OFF as per Figure 2), and sliding the board into an available connector slot. Jumpers (E7-E8, E10-E11, E13-E14) must be in place on the board for correct operation. Once the board is seated, the strain relief bracket screws are loosened to feed the cable(s) from the remote unit(s) between the bracket and the rear door, then tightened to secure the cables and provide an internal loop. This physical installation is a one-time process.
Software maintenance primarily revolves around ensuring the correct TRS-XENIX version is installed and that terminal configurations are accurately reflected in the /etc/ttytype and /etc/termcap files. The manual emphasizes the importance of the TRS-XENIX 01.03.00 version, indicating that any system running an older version must be updated. This update process, involving a software update diskette, is a critical maintenance step to ensure compatibility and proper functionality of the Multiterminal Interface. Regular checks of the system's /etc/ttytype file are recommended if new terminals are added or existing ones are changed, to ensure TRS-XENIX correctly identifies and interacts with them. The disable and enable commands serve as basic diagnostic and management tools for individual terminal ports, allowing administrators to bring terminals online or offline as needed, which is a form of operational maintenance. The design of the board, being an internal component, suggests that physical maintenance beyond initial installation is generally not required unless a hardware fault occurs, in which case professional service would likely be needed. The emphasis on software configuration and updates highlights the integrated nature of hardware and software in achieving the multi-user functionality.
Operating Environment| temperature range | 32 to 104° F (0 to 40° C) |
|---|---|
| storage range | -40 to 149° F (-40 to 65 ° C) |
| ambient humidity | 10 to 80% Relative (non-condensing) |
Other Specifications| maximum movement | 4.5" (110mm) horizontal and vertical |
|---|---|
| cable length | 5ft (1.5m) |
Weight and Dimensions| length | 3.5" (90mm) |
|---|---|
| width | 2.5" (62mm) |
| height | 1.3" (34mm) |
| weight | 6.8oz (210 grs) |
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