CMOS单元

unit CMOS;

Interface

const
ClockSec = $00; { RTclock seconds }
ClockMin = $02; { RTclock minutes }
ClockHour = $04; { RTclock hours }
ClockDOW = $06; { RTclock day of week }
ClockDay = $07; { RTclock day in month }
ClockMon = $08; { RTclock month }
ClockYear = $09; { RTclock year (mod 100)}
AlarmSec = $01; { Alarm seconds }
AlarmMin = $03; { Alarm minutes }
AlarmHour = $05; { Alarm hours }
Diskettes = $10; { Floppy disk type byte }
HardDisk = $12; { Regular hard disk type }
HDExt1 = $19; { Extended hard disk type, unit 1 }
HDExt2 = $1A; { Extended hard disk type, unit 2 }
Equipment = $14; { Equipment list }
CheckLo = $2F; { Checksum low }
CheckHi = $2E; { Checksum high }
BaseLo = $15; { Base mem low }
BaseHi = $16; { Base mem high }
ExpdLo = $17; { Expansion mem size low }
ExpdHi = $18; { Expansion mem size high }
StatRegA = $0A; { Status Register A }
StatRegB = $0B; { Status register B }
StatRegC = $0C; { Status register C }
StatRegD = $0D; { Status register D }
DiagStat = $0E; { Diagnostic status byte }
ShutDown = $0F; { Shutdown status byte }
Century = $32; { BCD Century number }
AltExpdLo = $30; { Expansion mem size low (alternate) }
AltExpdHi = $31; { Expansion mem size high (alternate) }
InfoFlags = $33; { Bit 7 set = top 128k installed, bit
6 set = first user message (?) }

function ReadCmos(Address: byte): byte;
{ Returns the byte at the given CMOS ADDRESS }

procedure WriteCmos(Address, Data: byte);
{ Writes DATA to ADDRESS in CMOS ram }

procedure SetCMOSCheckSum;
{ Sets the CMOS checksum after you've messed with it :-}

{ The following bytes are RESERVED: $11, $13, $1B-$2D, and
$34-$3F ($3F marks the end of the CMOS area). You'll note that
some of these are included in the checksum calculation. }

implementation

const
CmosAddr = $70; { CMOS control port }
CmosData = $71; { CMOS data port }

function ReadCmos(Address: byte): byte;
begin
{port[CmosAddr] := Address;
ReadCmos := port[CmosData]}
end; {ReadCmos}

procedure WriteCmos(Address, Data: byte);
begin
{port[CmosAddr] := Address;
port[CmosData] := Data;}
end; {WriteCmos}

procedure SetCMOSCheckSum;
{ The checksum is simply the sum of $10 to $2D
(some of these bytes are reserved) }

var
I, Sum: word;
begin
Sum := 0;
for I:= $10 to $2D do Sum := Sum + ReadCmos(I);
WriteCmos(CheckHi, Hi(sum));
WriteCmos(CheckLo, Lo(sum));
end; {SetCMOSCheckSum}

end.