• Please review our updated Terms and Rules here

486 and large compact flash drives

mojorific

Experienced Member
Joined
Nov 1, 2013
Messages
254
Location
Ontario, Canada
I have a nice little all-in-one AST Adventure! 4066d computer, and have been using a IDE to CF adapter for storage.

The system won't recognize anything beyond a 2GB compact flash, and was wondering if there is a way to allow me to have a larger drive than the on-board IDE controller can recognize. I checked to see if there was a BIOS update for larger drive support, but it doesn't look like there is one.

My thought is that I could add a SCSI card to circumvent the drive size limitation.

It only has 16 bit and 8 bit ISA slots (no PCI). Is it possible to get a SCSI card, and then use a SCSI to CF card to use larger drives? Anyone have a recommendation on what 16-bit SCSI card would work best for this application?


Thanks!
 
Since you said the system won't recognize anything larger than 2 GB I'm assuming you are having the BIOS related limition and not the DOS FAT 16 related limitation. Both result in a ~ 2 GB limit. You're not trying to access the larger than 2 GB drive via DOS 6.xx or lower, right? Because, if you have the DOS FAT 16 limitation the simple solution is multiple 2 GB partitions. But, if the 2 GB limit is BIOS related, then a controller upgrade will do the trick. So will a DDO but they have their own inherent problems even though this is one of the simpler to implement remedies for this situation.
 
The system won't recognize anything beyond a 2GB compact flash, and was wondering if there is a way to allow me to have a larger drive than the on-board IDE controller can recognize. I checked to see if there was a BIOS update for larger drive support, but it doesn't look like there is one.

32GB on a 386 - Smashing the 500MB barrier

 
I have a nice little all-in-one AST Adventure! 4066d computer, and have been using a IDE to CF adapter for storage.

The system won't recognize anything beyond a 2GB compact flash, and was wondering if there is a way to allow me to have a larger drive than the on-board IDE controller can recognize.


Thanks!

Ontrack Dynamic Disk Overlay Performance Investigation

 
XT-IDE is absolutely the way to go. Just burn a ROM, plug it into an option rom slog(say on a network card) and it "just works". Faster than a DDO too.
 
The problem is a BIOS one, and not a DOS size limitation (can't actually put in the correct settings in the bios to get the card to work and auto-sizing just hangs).

I do have a spare XT-IDE unit that i'll test in it, and I also have a couple new boards coming from jjpearce, (built 2 already
for a Tandy SL/2 and an EX).

The DDO option sounds interesting as well. I'll do some experimenting and post a reply. Thanks for all the feedback!
 
XT-IDE is absolutely the way to go. Just burn a ROM, plug it into an option rom slog(say on a network card) and it "just works". Faster than a DDO too.

I assume you mean using only the XT-IDE ROM to add large drive support to the computer's existing full 16-bit IDE interface? There were commercially available ISA cards to do that. Some only had the ROM while others provided their own 16-bit IDE interface as well.
 
XT-IDE is absolutely the way to go. Just burn a ROM, plug it into an option rom slog(say on a network card) and it "just works". Faster than a DDO too.
If you've got a ROM burner on hand, then yes. If not DDO does the trick and I've never found it a terribly traumatic experience to use. As Westlife mentions so do cards with their own bios such as the Promise IDE multi i/o cards.
 
If not DDO does the trick and I've never found it a terribly traumatic experience to use.

The only problem I've encountered is that it's hard to make them go away. I have a Western Digital 120 MB IDE drive that has a DDO installed and even doing an FDISK and FORMAT doesn't get rid of it. I don't know why it would even be needed on a drive that small, unless someone was putting it in an old 286 which only had pre-configured drive types in its CMOS and none of them were a good enough match.
 
It's been awhile, but have you tried booting from a floppy and overwriting the partition table with, say, FDISK /MBR?

Absent that, run the setup/uninstall utility from your original installation disk.

Or, move the card to a system that will boot Linux and just "dd if=/dev/zero count=1 of=(whatever your card's device address is)"

There are more ways that this...
 
My legit question is why you need more than two gigs of space? I put two gigs in a portable 386 and I'm hard pressed to even fill it a quarter the way with applications.
 
I suppose the answer would be "because you can". People generally like to push their PC's as far as possible.
 
Yes, there are vintage cards that will work too. But then you have to find one and buy one and it uses a slot.

And no, DDOs aren't too bad. I use one on my 486, because my caching controller doesn't work with XTIDE. It does cut a few FPS from DOOM, which isn't a big deal for me. But still the performance hit exists.
 
Aside from the performance hit there are the other inherent system difficulties that a DDO comes with such as:

1) DDO removal requires runing the setup program that put it there in the first place.

2) Mixing drives of different manufacturers in the same system

3) Booting from a floppy disk

4) Multi-booting OSes

5) 'Non-standard' OSes, in general

But if you're not doing anything that would be sensitive to the above issues they're certainly a viable and quite simple to implement option.
 
Back
Top