486 machines particularly older ones with VLbas opposed to PCI tend to have 512Mb or 2GB IDE size limits in BIOS I have seen very few boards that do up to 8GB prior to Socket 7, and never without a modded BIOS.

Second appiah4's comment.

Older BIOSes in 286, 386 & even some 486 PC's are normally limited to 504 MiB or 528 MB (depending on how you calculate it). So, regardless of the size of your storage device (SD card or CF card), the BIOS will only be able to read up to this maximum limit. In such a case, you can just insert the following parameters: 1024 cylinders, 16 heads & 63 sectors. Using the maximum cylinders of 1024, this should then give you a total capacity of 528,482,304 bytes = 504 MiB (or 528 MB). Based on what the OP mentioned, it would appear that his BIOS has a 4 GB hard drive size limit (8192 cylinders, 16 heads, & 63 sectors x 512 sectors per track = 4227858432 bytes or 4.22 GB or 3.94 GiB). Refer this page for more information on the limits: http://tldp.org/HOWTO/Large-Disk-HOWTO-4.html.

However, this would be a waste of the available storage space if you have large sized Compact Flash card. To overcome this, you can either use Dynamic Drive Overlay (DDO) software or, you can plug in a network card with a Boot ROM socket, flash an EEPROM chip with the XT-IDE BIOS and then let that BIOS "take over" the function of the main BIOS (in terms of hard drive parameters).

Just bear in mind that DOS (up to 7.0 and 7.1 onwards if formatted with FAT16) is limited to a maximum partition size of 2 GB (you can, however, create multiple partitions).

With Compact Flash cards, I've also had mixed results with some of these CF to IDE adapters. My experience has been that the one with the bracket and with the male connector (i.e., you have to connect an IDE cable to it just like you would connect to a hard drive) works better than the other adapter with the female connector (that you can connect directly to the IDE interface card).

Ok, so maybe it is my adapter then. I have the one with the female end. I felt dumb when I realized I ordered the adapters with the female end.

I wonder if it has something to do with signaling strength or timing as the adapter cards are pretty much identical. I wonder if the extra length on the IDE cable (signal timing and strength) is what makes the difference.

Both the motherboard BIOS and the IWILL SIDE BIOS have LBA support with the IWILL card specifically having a setting for 528MB+ support.

The BIOS does detect two of the cards at around 8GB, so I think the support is actually there, especially since the one VLB card (without BIOS) works ok-ish with the one card even though while the motherboard BIOS detects the ~8GB size, fdisk will only create a slightly smaller than 4GB partition.. says that is all the space on the drive.

Oh yeah.. I also have another VLB I/O card without a BIOS where the other card that detects will letr it format to the fully detected size.. but then freaks out after rebooting and says the drive is unreadable.

The IWILL BIOS also has settings for IDE timing, but since I don't have the manual I have absolutely no idea what changing any of them would do.

There is a setting on the IWILL card for INT-13.. Move to RAM, ROM BIOS (IWILL card bios), and SYSTEM ROM. Changing to System ROM or ROM BIOS makes it behave slightly different but it still doesn't work like it should.

The motherboard I am using is a PC-Chips M912 v1.4. It has a UMC 5x86/486 chipset and the specs say it supports up to 4 IDE drives and LBA.

I do have a newer BIOS I could try flashing to it. Maybe that would help something but I have no information on what the changes are and the place I got it from didn't have any list of changes either.

Edit: I just ordered a few of the CF to IDE adapters that have the male plug on them.. Now to wait for them to get here to see if that helps at all.

cyclone3d wrote:

Ok, so maybe it is my adapter then. I have the one with the female end. I felt dumb when I realized I ordered the adapters with the female end.

I also have one of these adapters, plack PCB with a FDD molex for power, can be set for master or slave for no reason (it can't be chained on an IDE ribbon so wtf?) and this adapter does not work on ANY motherboard I have whatsoever.

I've heard of other people who use it just fine, but either mine is a complete dud or it's not compatible with some motherboards at all. I've also heard stories of people using gender changers to turn it into a male adapter, and use it with an IDE cable - and only then it would work. YMMV.

Get a better adapter, anyhow.

That is the exact adapter I have right now. Grrrr. That makes me think even more that it has something to do with the IDE cable changing the signal strength and timing.

I thought about getting a gender changer, but the only ones I could find were about 4-5x the cost of an adapter with the male plug so there was no point in getting one.

I just installed this 44-pin cf adapter in my 486 laptop.

https://www.reichelt.de/?ACTION=3;ARTICLE=120 … pact%20flash%20

Because it shipped with what I assume is an adapter from 44 pin to "regular" 40 pins, I'm guessing you can run the adapter off the IDE without needing extra power via molex?
Maybe that could make a difference for you.

appiah4 wrote:

I also have one of these adapters, plack PCB with a FDD molex for power, can be set for master or slave for no reason (it can't […]
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cyclone3d wrote:

Ok, so maybe it is my adapter then. I have the one with the female end. I felt dumb when I realized I ordered the adapters with the female end.

I also have one of these adapters, plack PCB with a FDD molex for power, can be set for master or slave for no reason (it can't be chained on an IDE ribbon so wtf?) and this adapter does not work on ANY motherboard I have whatsoever.

I've heard of other people who use it just fine, but either mine is a complete dud or it's not compatible with some motherboards at all. I've also heard stories of people using gender changers to turn it into a male adapter, and use it with an IDE cable - and only then it would work. YMMV.

Get a better adapter, anyhow.

Yes, this is the one that also gave me problems. Luckily, back then, I bought both and the other one (with the bracket) works on all my configurations.