Dear Vogons members and enthusiast,

This is my first post in the forum. After many days of reading and research (during which I have learnt a lot), I have faced a bricked wall and I need help from experts.

I have an old Toshiba T1910CS laptop, originally with DOS/Win3.x, then I upgraded it to Windows 95 SR2.5. I would like to expand the storage capacity by using a CF card in the PCMCIA socket, so I bought one of these cheap adapters from Aliexpress and a 512 MB Compact Flash. I can read/write the CF from my everyday laptop using a USB-CF reader. The partition is FAT16, to maximize compatibility with DOS/Win3.x/Win95.

From what I have read, Win95 should be able to access the CF almost automatically. However, this is not my case. This is what I have achieved so far:

1. The PCMCIA socket drivers are installed and work correctly. I am using the default PCMCIA PCIC compatible controller (I do not know the specific hardware, but the generic driver seems to work fine)
2. When the card is inserted, Win95 detects it correctly. A pop-up with the CF brand and model shows up (TRANSCEND-TS512MCF80).
3. Next, the driver installation wizard starts, recommending the standard IDE/ESDI disk controller. I follow instructions and the wizard finishes successfully. A beep sound is generated.
4. The new IDE/ESDI controller shows up in the Device Manager, next to the internal HDD driver. Resources allocated (I/O ports and IRQ) correspond to secondary IDE (0x170-0x177, IRQ 15). No conflicts.
5. However, no driver letter is assigned to the CF and no drive unit is shown in My PC.
6. If I check the Removable tick box in the Generic IDE Disk configuration, then the unit shows up, but when I try to access, the computer freezes for a few seconds, then it says that the unit cannot be accessed.

A couple of things I have done to verify that the PCMCIA and the CF card are working fine:

1. If I load APSoft ATAENAB (DOS Enabler for ATA Cards) from Config.sys, the CF is recognized, I/O port allocated is 0x150 (no IRQs needed), driver letter D: is assigned and shown in My PC and I can access the CF without problem. Windows 95 complains about real-mode drivers detected and potential loss of performance in compatibility mode, though.
2. If I insert a network card in the PCMCIA socket (Buffalo LPC3-TX), after installing the drivers the card works flawlessly. I can even access Google from this 30 year-old laptop!!! 😀

This made me think that the root cause might be in the IDE/ESDI driver. There must be a difference between the ATA/IDE driver embedded in ATAENAB (which works) and the driver provided by Windows 95 (which fails), so I started to read about ATA protocol when I came across this post:
http://support.fccps.cz/download/adv/frr/cf.html

Apparently, these cheap CF-PCMCIA adapters are missing some signals in the wiring that prevents access to the CF card if DMA mode or ATA PIO modes above 2 are used. Could it be that Windows 95 IDE/ESDI driver is trying to access the CF in a different mode compared to ATAENAB? Can this be adjusted in the driver configuration? Or am I talking non-sense and the problem relies somewhere else?

Any help will be much appreciated. I am really lost and nearly to the point of giving up.

Thanks everyone in advance!
BR