Technical Reference Manual for the ThinkPad 600
Page 45
... D (Hex 00D) Bit Function 7 Valid RAM 6-0 Reserved Figure 2-20. These bits are reserved. Status Register D (Hex 00D) Bit 7 Bits 6-0 This read-only bit monitors the internal battery. If set to 0, it indicates that an alarm interrupt has occurred. System Board 2-23 Status Register C (Hex 00C) Bit Function 7 Interrupt request flag 6 Periodic interrupt... flag 5 Alarm interrupt flag 4 Update-ended interrupt flag 3-0 Reserved Figure 2-19. Status Register C (Hex 00C) Note: Interrupts are enabled by bits 6, 5, and 4 in CMOS is no longer valid.
... D (Hex 00D) Bit Function 7 Valid RAM 6-0 Reserved Figure 2-20. These bits are reserved. Status Register D (Hex 00D) Bit 7 Bits 6-0 This read-only bit monitors the internal battery. If set to 0, it indicates that an alarm interrupt has occurred. System Board 2-23 Status Register C (Hex 00C) Bit Function 7 Interrupt request flag 6 Periodic interrupt... flag 5 Alarm interrupt flag 4 Update-ended interrupt flag 3-0 Reserved Figure 2-19. Status Register C (Hex 00C) Note: Interrupts are enabled by bits 6, 5, and 4 in CMOS is no longer valid.
