INT 15 - Amstrad PC1512 - WRITE DATA TO NON-VOLATILE RAM
AL = NVRAM location (00h to 3Fh)
00h BYTE time of day: seconds
01h BYTE alarm time: seconds
02h BYTE time of day: minutes
03h BYTE alarm time: minutes
04h BYTE time of day: hours
05h BYTE alarm time: hours
06h BYTE day of week, 1 = Sunday
0Ah BYTE RTC status register A
bit 7: set if date/time being updated
6-4: time base speed, default 010 = 32768 Hz
3-0: interrupt rate selection, default 0110 = 1024 Hz
0Bh BYTE RTC status register B
bit 7: clear if normal update, set if abort update
6: periodic interrupt enable
5: alarm interrupt enable
4: update end interrupt enable
2: date mode (clear = BCD, set = binary)
0: daylight saving time enable
0Ch BYTE RTC status register C (read-only)
0Dh BYTE RTC status register D
0Eh 6 BYTEs time and date machine last used
14h BYTE user RAM checksum
15h WORD Enter key scancode/ASCII code
17h WORD Forward delete key scancode/ASCII code
19h WORD Joystick fire button 1 scancode/ASCII code
1Bh WORD Joystick fire button 2 scancode/ASCII code
1Dh WORD mouse button 1 scancode/ASCII code
1Fh WORD mouse button 2 scancode/ASCII code
21h BYTE mouse X scaling factor
22h BYTE mouse Y scaling factor
23h BYTE initial VDU mode and drive count
24h BYTE initial VDU character attribute
25h BYTE size of RAM disk in 2K blocks
26h BYTE initial system UART setup byte
27h BYTE initial external UART setup byte
28h 24 BYTEs available for user application
Note: bytes 00h-0Dh are the same on the IBM AT as they are used/updated by