SECTION 6
Conversions and Interfaces
PEN*KEY
R
6200/6300 Hand-Held Computer Programmer’s Reference Guide 6-59
INT 13h, Function AH = DAh: Disable RAM Drive Access
BIOS
Reprograms memory controller to disable access to RAM associated with RAM
drive.
On Entry:
AH = 0DAh
DL = 00 h
On Return:
AH =00h
INT 13h, Function AH = EAh: Enable RAM Drive Access
BIOS
Reprograms memory controller to enable access to RAM associated with RAM
drive.
On Entry:
AH = 0EAh
DL = 00h
On Return:
AH = 00h
INT 13h, Function AH = ECh: Enable Checksum of RAM Drive Integrity
Memory
BIOS
Copies following RAM drive signature into RAM drive logical boot sector's
reserved portion.
_RamDriveSignature label byte
db “Norand RamDrive”,0
db 0,0, 0Fh, 0FFh,0FFh,0FFh
db 0F0h, 3Ch,99h,0C3h, 55h,0AAh
On Entry:
AH = 0ECh
ES:SI = Pointer to Global Descripter Table (GDT):
Offset Ċ Uninitialized
00h = Null descripter
08h = Will be made into GDT descripter
10h = Descripter for source of move
18h = Descripter for destination move
20h = Unused by BIOS
28h = Will be made into SS descripter 0
On Return:
If successful:
Carry = 0
AH = 00h (normal return)
If NOT successful:
Carry = 1
AH = Status:
01h = Parity error
02h = Interrupt error
03h = Address line 20 gating failed
6. Conversions and
Interfaces
