INT 15 - Amstrad PC1512 - WRITE DATA TO NON-VOLATILE RAM(Random Access Memory) See also DRAM, SRAM. AH = 01h AL = NVRAMsee Non-Volatile RAM location (00h to 3Fh) (see #00405) BL = NVRAMsee Non-Volatile RAM data value Return: AH = return code 00h OK 01h address bad 02h write error SeeAlso: AH=02h"Amstrad" Format of Amstrad NVRAMsee Non-Volatile RAM: Offset Size Description (Table 00405) 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 07h BYTE day of month 08h BYTE month 09h BYTE year mod 100 0Ah BYTE RTCsee Real-Time Clock status register A (see #00406) 0Bh BYTE RTCsee Real-Time Clock status register B (see #00407) 0Ch BYTE RTCsee Real-Time Clock status register C (read-only) (see #00408) 0Dh BYTE RTCsee Real-Time Clock status register D bit 7: battery good 0Eh 6 BYTEs time and date machine last used 14h BYTE user RAM(Random Access Memory) See also DRAM, SRAM. 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(Video Display Unit) Mainframe-speak for computer monitor. mode and drive count 24h BYTE initial VDU(Video Display Unit) Mainframe-speak for computer monitor. character attribute 25h BYTE size of RAM(Random Access Memory) See also DRAM, SRAM. disk in 2K blocks 26h BYTE initial system UART(Universal Asyncronous Receiver/Transmitter) A peripheral device which converts a sequence of bytes into a serial bit stream at a programmable rate, and vice versa. This device is what makes an RS-232 serial port function. See also USART. setup byte 27h BYTE initial external UART(Universal Asyncronous Receiver/Transmitter) A peripheral device which converts a sequence of bytes into a serial bit stream at a programmable rate, and vice versa. This device is what makes an RS-232 serial port function. See also USART. setup byte 28h 24 BYTEs available for user application Note: bytes 00h-0Dh are the same on the IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. ATIBM PC AT as they are used/updated by the clock chip Bitfields for RTCsee Real-Time Clock status register A: Bit(s) Description (Table 00406) 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 SeeAlso: #00405 Bitfields for RTCsee Real-Time Clock status register B: Bit(s) Description (Table 00407) 7 clear if normal update, set if abort update 6 periodic interrupt enable 5 alarm interrupt enable 4 update end interrupt enable 3 square wave enable 2 date mode (clear = BCD(Binary Coded Decimal) A method of data storage where two decimal digits are stored in each byte, one in the upper four bits and the other in the lower four bits. Since only the values 0 through 9 are used in each half of a byte, BCD values can be read as decimal numbers on a hexadecimal display of memory or a file., set = binary) 1 24-hour format 0 daylight saving time enable SeeAlso: #00405 Bitfields for RTCsee Real-Time Clock status register C: Bit(s) Description (Table 00408) 7 IRQF flag 6 PF flag 5 AF flag 4 UF flag SeeAlso: #00405