Appendix A from the DVI Manual Connector Pin Assignments System Bus Connector Pin No. Symbol Description 1 VDD +5V Power Supply from TRS-80 Model 100 2 VDD +5V Power Supply from TRS-80 Model 100 3 GND Logic Ground 4 GND Logic Ground 5 AD1 Address Data Signal bit 1 6 AD0 Address Data Signal bit 0 7 AD3 Address Data Signal bit 3 8 AD2 Address Data Signal bit 2 9 AD5 Address Data Signal bit 5 10 AD4 Address Data Signal bit 4 11 AD7 Address Data Signal bit 7 12 AD6 Address Data Signal bit 6 13 A 9 Address Signal bit 9 14 A 8 Address Signal bit 8 15 A 11 Address Signal bit 11 16 A 10 Address Signal bit 10 17 A 13 Address Signal bit 13 18 A 12 Address Signal bit 12 19 A 15 Address Signal bit 15 20 A 14 Address Signal bit 14 21 GND Logic Ground 22 GND Logic Ground 23 WR Write enable Signal 24 RD Read enable Signal 25 S0 Status 0 Signal 26 IO/M I/O or Memory Signal 27 S 1 Status 1 Signal 28 ALE Address Latch enable Signal 29 Y0 I/O Controller enable Signal 30 CLK 2.54 MHz Clock Signal 31 RESET TRS-*) Model 100 Reset Signal 32 A Memory or I/O Access enable Signal 33 INTA Interrupt acknowledge Signal 34 INTR Interrupt request Signal 35 GND Logic Ground 36 GND Logic Ground 37 NC No connection 38 RAM RST TRS-80 Model 100 RAM reset Signal 39 NC No connection 40 NC No connection