Texas Instruments 660 System Boots: External Keyboard Checks

5-32 Troubleshooting Procedures
Figure 5-17 External Keyboard Function Troubleshooting Diagram
Figure 5-18 PS/2 External Mouse Function Troubleshooting Diagram
16
Check Keyboard Data Check U8(38813)
Pin17 EXT1DATA
Signal
Check Keyboard Clock Check U8(38813)
Pin16 EXT1CLK
Check IRQ Signal Check U8(38813)
PIN15 IRQ1
END
Yes
No
Yes
Yes
No
System Boots:
External Keyboard Checks
17
Check Mouse Data Check U8(38813)
Pin12 EXT2DATA
Check Mouse Clock Check U8(38813)
Pin13 EXT2CLK
Check IRQ Signal Check U8(38813)
PIN14 IRQ12
END
Yes
No
Yes
Yes
No
No
System Boots:
PS/2 External Mouse Interface Check