Radio Shack
TRS-80
EXPANSION
INTERFACE
SEE CAUTION
INSIDE COVER
Catalog Numbers 26-1140
26-1141
26-1142
Operator's Manual
CUSTOM MANUFACTURED IN U.S.A. FOR RADIO SHACK [TC] A DIVISION OF TANDY CORPORATION
INTRODUCTION
The TRS-80 Expansion Interface (see Figure 1) consists of the Case, a DC Power Supply, a Ribbon Cable, a CassetteRecorder Jumper Cable and an additional Cassette Recorder Cable for Cassette Recorder number 2. Notice that the DCPower Supply is not installed in the Case upon receipt. It must be installed using the procedures under the heading"SETTING UP" and as illustrated in Figure 2.
The Case houses the Expansion Interface Printed Circuit Board (PCB), two DC Power Supplies and provides a housingarea for an additional expansion PCB. The Expansion Interface utilizes a real-time clock and contains sockets for theaddition of up to 32K of RAM in 16K increments.
One DC Power Supply provides power to the PCB. The other one supplies power to the TRS-80. The Power Suppliesare interchangeable.
The ribbon cable has 40-pin connectors on both ends and is used to connect the Expansion Interface to the TRS-80.You received hoods for these connectors which are covered later in this manual.
The Cassette Recorder Jumper Cable has 5-pin audio DIN connectors on both ends. It connects between the ExpansionInterface Tape input/output (I/O) and the TAPE connector on the right rear of the TRS-80 Microcomputer.
The Cassette Recorder Cable is provided to connect the Expansion Interface to Cassette Recorder number 2.
CAPABILITIES AND ADVANTAGES
The Interface allows you to add the following Radio Shack modules to your system:
1. Screen Printer (26-1151)
2. Line Printer (26-1150)
3. Mini-Disk System (26-1160/26-1161)
4. Cassette Recorder number 2 (14-841)
The Screen Printer and Line Printer allow you to obtain hard copy (printed) information generated by your TRS-80.
The TRS-80 Mini-Disk System is a small version of the floppy disk. It provides vast storage space and much quickeraccess time than tape. The number 1 disk contains about 80,000 bytes of free space for files. Each additional disk has89,600 bytes of file space. The Disk System has its own set of commands that allow manipulation of files and expandedabilities in file use. The TRS-80 Mini-Disk System uses sequential or random access. The disks will allow use ofseveral additional LEVEL II commands.
IMPORTANT NOTE
Because of the presence of a Disk Controller in the ExpansionInterface, the computer will try to input the additionalcommands.
When the Expansion Interface is connected to the computer,it assumes that a Mini-Disk is connected. To use theExpansion Interface without a Mini-Disk, press the BREAKkey on the TRS-80 keyboard. This will override the Mini-Diskmode and allow normal LEVEL II operation.
The use of two cassettes allows a much more efficien