Hi Mike, Andrew, > You should look for a product called "Disk On Module". They are > composed of FLASH chips and are designed to be direct replacements for > IDE hard drives. Unlike a lot of CF cards that can be used with an CF > to IDE adapter but might not support CHS addressing, DOMs are designed > as IDE replacements so they do proper wear leveling and will fully > emulate an IDE device, including both CHS and LBA addressing. > (A lot of newer CF cards only do LBA addressing.)
So far, I never had problems with CHS versus LBA and for me CF cards *would* be full replacements for IDE disks with a simple mechanical adapter... CF cards already "speak" IDE, no extra controller needed. HOWEVER, I get the impression that CF cards are optimized for use in digital SLR cameras: So they are fast when you write a few files of a few MB each while taking pictures... Yet they are not that fast if you write many small files or want to copy around ISO images etc ;-) On the other hand, running Windows 3 from USB sticks with BIOS USB 1 drivers is no fun either - slow transfer speed and low IOPS number of accesses per second. Something as old as Windows 3 of course will easily fit inside a RAMDISK today even on an old computer :-p I think DOM targets a very specific market, which you may also see in their prices. For a simple Child FreeDOS computer, any storage will be good enough, be it USB sticks (glue a micro one to the port if you worry about vandalism) or SD cards (even embedded system and server boot disks are happy enough with SD) or CF cards or DOM :-) And when you worry about speed - copy things to a RAM disk at boot. > DOMs come in both 40 and 44 pin varieties and range in size from 32MB > to 4 or 8GB. Actually you might even be able to find a bit of storage in the BIOS chip of something if you only need 32 MB of space, who knows? Hehe. > Assuming the BIOS of your machine can autodetect hard drives, using a > DOM as a replacement for a hard drive should be easy. Some early > machines restrict the choice of hard drive by hard coding the BIOS to > only accept certain models; those BIOSes need to be patched... Never happened to me, although 20 years ago, I had a BIOS which was only able to do CHS in the old "512 MB limit" style for DOS, with an extension for "more cylinder bits in the head number byte" which let you reach 8 GB in a totally incompatible way to the "up to 256 heads but only 1024 cylinders" way of modern BIOSes that DOS would expect. > But a conventional IDE BIOS should work fine with a DOM. Also worked fine with CF, just the performance even of the best CF that I have is much less exciting than that of a PC-oriented SSD ;-) Eric PS: SOME CF also have the problem to "hang" from time to time if you keep them too busy - cameras do not, but on PC it really annoyed me. ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Freedos-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freedos-user
