Technical information

Contents
SETTING UP
Installing the Power Supplies .. . . . . . . . . . . . . . . . . . . . . . . . 3
Cables, Card-Edges and J aGks , 4
Connection to the TRS-80 ; . . .. 6
Power-Up and Notes 8
Adding RAM 10
PERIPHERALS
Dual Cassettes 12
Line Printer , 14
Mini-Disk(s) 16
Bus~ompatible Devices . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16
Expansion Board 16
TECHNICAL INFORMATION
25 mS Heartbeat Interrupt . . . . . . . . . . . . . . . . . . . . . . . . .. 20
Floppy Disk Controller IC ... . . . . . . . . . . . . . . . . . . . . . .. 24
Address Decoding Scheme . . . . . . . . . . . . . . . . . . . . . . . . .. 25
Cassette Jack Signals 26
Line Printer Card-Edge Signals . . . . . . . . . . . . . . . . . . . . . .. 28
Mini-Disk Card-Edge Signals. . . . . . . . . . . . . . . . . . . . . . . .. 29
Bus Card-Edge Signals 30
Expansion Board Card-Edge Signals . . . . . . . . . . . . . . . . . .. 31
TROUBLESHOOTING
Reference Materials 34
Disassembly 34
Power Supply Checks and Adjustments 36
Schematic Diagrams , 38
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