When I insert a 16-bit PCMCIA Card into computer equipped with O2Micro CardBus adapter - nothing happens. Card is not recognized.
Synopsis: Your computer is equipped with O2Micro CardBus adapter. CardBus cards are working OK, but when 16-bit card is inserted - card is not recognized. No beeps are produced. Card is not shown by PCCard.exe.
Reason: This is a problem with some of O2Micro CardBus adapters.
Explanation:
There is 2 basic method for power 16-bit card:
    - ExCA (or 16-bit) Power-Up procedure and
    - CardBus Power-Up procedure.
On standard CardBus adapter - there is no difference which one to apply to 16-bit cards.
 
On old O2Micro adapters, however, usage of CardBus power-on algorithm with Intel Flash cards put cards into non-functional state. For this reason CardWare was using ExCA Power-Up procedure on O2 Micro adapters.
 
Since Microsoft starting Windows 2000 is using only CardBus Power-Up procedure, at certain point O2Micro fixed CardBus algorithm and for couple of years both algorithms were functional.
 
Unfortunately in 2007 we noticed that O2Micro lost compatibility with 16-bit Power-Up algorithm: if Card is powered-up via ExCA registers. CardBus "Power-Up Cycle Done" is never signaled.

Starting with CardWare for Windows 2000/XP and Server 2003 version 7.00.015 and CardWare for Windows Vista version 7.00.003 ExCA Power-Up procedure is used by default for O2Micro adapters with device ID smaller as 0x7000 and CardBus Power-Up procedure is used by default for O2Micro adapters with device ID greater as 0x7000.

Unfortunately, O2Micro Inc. not always assign new device ID to new CardBus adapters. Many of even recent releases of O2Micro CardBus adapters still using Device ID 0x6933 (OZ6933 was quite popular by end of last century nineties). Furthermore O2Micro doesn't document usage of Revision ID register and software is not always able distinguish between an "old" and a "new" adapter.

Solution: Starting with CardWare for Windows 2000/XP and Server 2003 version 7.00.015 and CardWare for Windows Vista version 7.00.003 APSoft introduced specific registry parameter 'O2MicroPowerOnMode' allowing to override 16-Bit Power Up procedure on O2Micro adapters. This parameter is located in HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\pccs\options and defined as follow (REG_DWORD):

0 - Auto (default). ExCA Power-Up procedure is applied for O2Micro adapters with device ID smaller as 0x7000 and CardBus Power-Up procedure is applied for O2Micro adapters with device ID greater as 0x7000.

1 - Force ExCA Power-Up procedure.

2 - Force CardBus Power-Up procedure

This parameter have no effect on other CardBus adapters and no effect on Power-Up of CardBus cards.