PDC20230-B

Code name: TurboChip B
Manufacturer: Promise Technology, Inc., in 1993
Function: VESA Local Bus IDE controller
Features
  • one fixed IDE channel
  • speed settable by jumpers to 0, 1, 2
  • ID3 pin sense (not always used)


    • Used in: Promise DC2000, DC4000 controllers.
    Manufacturer support: none.
    Documentation available: none.
    Drivers available: DOS, Win 3.1x, WinNT 3.1, Netware 386 3.1x, 4.01, OS/2 2.0, 2.1x, SCO Unix, AT&T UNIX System V/386

    This chip can be detected by following sequence: 

    mov dx, 0x1F2
mov al, 0x55
out dx, al
cli
in al, dx
in al, dx
in al, dx
sti
cmp al,0
    PDC20230-B clears sector count register after 3 successive reads.
    The last value read from 0x1F2 port is 0 for PDC20230-B, 0x55 for other controllers.

    PDC20230-B requires VLB sync sequence for 32-bit I/O: 

    cli
mov dx, 0x1F2
in al, dx
in al, dx
in al, dx
sti

    updated 21-May-2000 by Petr Soucek