Texas Instruments 660 - Manual (Page 70)

5-10 Troubleshooting Procedures
3-1-2 21h Master DMA Register Failure
3-1-3 22h Master Interrupt Mask Register Failure
3-1-4 23h Slave Interrupt Mask Register Failure
None 25h Interrupt Vector Loading In Progress
3-2-4 27h Keyboard Controller Test Failure
None 28h CMOS Power Failure and Checksum in Progress
None 29h CMOS Configuration Validation in Progress
3-3-4 2Bh Screen Memory Test Failure
3-4-1 2Ch Screen Initialization Failure
3-4-2 2Dh Screen Retrace Test Failure
None 2Eh Search for Video ROM in progress
1-2 2Eh Cirrus Video Chip Failure
1-3 2Eh Cirrus RAM DAC or Video RAM Failure
None 30h Screen Believed Operable; running with Video ROM
None 31h Monochrome Monitor Believed Operable
None 32h Color Monitor (40 Column) Believed Operable
None 33h Color Monitor (80 Column) Believed Operable
4-2-1 34h No Time Tick
4-2-2 35h Shutdown Failure
4-2-3 36h Gate A20 Failure
4-2-4 37h Unexpected Interrupt in Protected Mode
4-3-1 38h Memory High Address Line Failure at 010000h-0A0000h
4-3-3 3Ah Timer Chip Counter 2 Failed
4-3-4 3Bh Time of Day Clock Stopped
4-4-1 3Ch Serial Port Failure
4-4-2 3Dh Parallel Port Failure
4-4-3 3Eh Math Coprocessor Failure
Table 5-3 Self Test Beep Messages
Beep Code Port 80h Description