hyoenmadan wrote:

I wouldn't recommend any Flash Memory based solution to replace an HDD in DOS...

The biggest problem comes from the fact that you can't really align DOS partitions and writable FAT cluster blocks to flash media Memory Erase page blocks...

In what context or scenario is this honestly a problem, when describing a DOS-based system? Have you experienced any such problems personally?

Having enjoyed the speed, silence, and convenience of using CompactFlash cards as hard-drive replacements for a full decade now, the concern over partition alignment in DOS-based systems seems like academic FUD.

Orkay wrote:

On an additional note, if you want an old 486 computer to use a large IDE hard drive or a CF card, it may be necessary to install a separate PCI controller (assuming the computers in question have PCI). The Promise Ultra33 has worked well for me on my 486, although certainly not as fast an Ultra66, Ultra100, or the like.

hyoenmadan wrote:

I wouldn't recommend any Flash Memory based solution to replace an HDD in DOS and old windows versions except for very specific embedded solutions were the Flash Disk works as readonly media image and all is written to RAM.

On top of that, if you plan to run Windows on your machine, virtual memory can wear out CF cards faster. Of course, disabling virtual memory will prevent this issue, but there comes the increased risk of running out of RAM.

The read/write wear on CF cards under Dos is minimal and likely to be good for many years plus the cost is really fair compared to burning money on old drives that are likely to go tits up at the most inconvenient time. The reason why I don't like SD cards is that I have already had some go bad on me from only light use while CF cards just keep on going.

I ignore SCSI because it is more expensive and sometimes troublesome if things don't go just right.

In my experience using CF cards with a CF-IDE adapter for DOS 6.22/Windows 3.1 builds has been very convenient. Every I/O controller card detects the adapter without issues, and performance doesn't seem to be a problem (in fact, I get better read/write speeds with CF cards than with my old IDE drives). Even low end CF cards will probably be bottlenecked by the controller on older (486 and below) PCs.

And add to that the fact that CF based solutions are completely silent, unlike the "jet engine" sound of some older drives! 🤣

For machines with newer versions of Windows there could be issues with the fact that many CF cards cannot be set as fixed drives (apparently Windows doesn't like to boot from removable drives, DOS doesn't care about that though), and also the constant writing to the swap file may affect performance but I really don't have any data to back this up. However, a SATA to IDE adapter is a great solution here if you don't have any IDE drives available.

Also, there was a mention of the OS or controllers not being "flash media aware"... I think you may lose a few features such as TRIM on SSDs, but they should still work properly, after all that is the point of having common interfaces such as IDE or SATA.

TheMobRules wrote:

Also, there was a mention of the OS or controllers not being "flash media aware"... I think you may lose a few features such as TRIM on SSDs, but they should still work properly, after all that is the point of having common interfaces such as IDE or SATA.

Here the interface has nothing to do. Flash media aware OS means the OS knows it is running from flash and adapt IO Transfer Block Size/Write Block Size/Erase block size according the situation and the used media (SD/CF/SSD/USB thumbdrive etc). It can be SCSI/ATA/USB/SPI/Hardwired etc... What is important is that OS knows it is running from flash media and can deal with these IO parameters, so you don't screw internal wear leveling optimization and your write operations don't become slower than write to a floppy disk. I'm aware that there were DOS/Windows versions optimized for embedded usage and running from flash media, but normal retail DOS/Windows aren't.

TheMobRules wrote:

And add to that the fact that CF based solutions are completely silent, unlike the "jet engine" sound of some older drives! 🤣

A retro system will never be "silent", specially if you need run it with an older power supply. Also don't be childish, I'm not saying you're forced to use big 5xx ST-506 drives or old SASI/SCSI drives. Any 20/40/80GB Laptop ATA drive will do the work well enough and them will be enough silent, some of them even more than your actual power supply fan.

brostenen wrote:

Then tell me, why do people here constantly reporting great results when using CF cards in MS-Dos-6.22?
Not why it's working, just why so many people reports good results.

And many of them report boot failure, or their writting speeds being slower than writting to a floppy drive 😜. Just search Vogons marvin section, you will see them.

Just CF media wasn't designed to be used as HDD replacement, nor old retro OSs were designed to run from Flash media, these are the only facts. In any case, is just a recommendation as OP asked. Anyone can use whatever they want to run their systems.

The boot failure issue under DOS with CF is generally resolved by simply running FDISK /MBR after installing. I haven't heard many people complaining about write speed under DOS with CF either, as it was said before DOS doesn't do massive writing to the HDD in normal situations.

Anyway, in my case (and I guess many others here) I will keep using CF cards for DOS builds because it has been the best solution for several years without encountering problems.

And I'm not being childish, low noise is important to me, my AT power supplies are generally pretty quiet, especially compared to the 4GB and smaller drives I have.

TheMobRules wrote:

The boot failure issue under DOS with CF is generally resolved by simply running FDISK /MBR after installing. I haven't heard many people complaining about write speed under DOS with CF either, as it was said before DOS doesn't do massive writing to the HDD in normal situations.

Anyway, in my case (and I guess many others here) I will keep using CF cards for DOS builds because it has been the best solution for several years without encountering problems.

And I'm not being childish, low noise is important to me, my AT power supplies are generally pretty quiet, especially compared to the 4GB and smaller drives I have.

Agreed 😀

I installed CF cards on a few of my older PCs. On my XT no matter what inneficiencies could be introduced by a flash-memory unaware OS the CF card is bound to be bottlenecked by the 8-bit ISA BUS. On my 486 the performance is quite fine, the PC feels very snappy. Also, I have a hard time believing any parameters set by the OS could ever screw the wear leveling algorithm so bad that it won't work correctly as long as you leave a good amount of free/unnalocated space. I'm not fond of using flash memory for Win9x and beyond, though.

I also have a hard time standing noisy PCs for long periods of time., and changing the fan of an old PSU doesn't even require a soldering iron.

hyoenmadan wrote:

And many of them report boot failure, or their writting speeds being slower than writting to a floppy drive 😜. Just search Vogons marvin section, you will see them.

Then you must choose those cards and adaptors that work. It's like expecting ATA-133 speed from an old 120mb PATA drive.
That aside... Same speed or slower than floppy? 😳 Nope... They have used the wrong cards, or wrong adaptors.
(quite possible both wrong ones)

Again... Use the right equipment, and CF cards are ok for old 286's up to Pentium-1 when running MS-Dos 6.22

Or if you happen to have an old iPod mini 4gb, you could crank that open in order to get that 4gb micro drive.
It should be CF compatible, as a lot of modders are replacing that with a 32gb CF card.

I tried a few micro drivers and found them to be extremely slow. I can't recommend them to be honest.

PhilsComputerLab wrote:

I tried a few micro drivers and found them to be extremely slow. I can't recommend them to be honest.

Learned my lesson with those horrendous 1.8 in ide drives (got a few tablets).

PhilsComputerLab wrote:

I tried a few micro drivers and found them to be extremely slow. I can't recommend them to be honest.

Ahhh... Did not know that. How fast.... I mean... How slow are they in transfer speed and seek times.
When I think back to 1992/94, possibly 1995, norton usually reported something like 600kb to 1200kb in transfer speed.
That was with standard 210mb to 500mb PATA drives back in those years. (386/486 era stuff)

So slow that you get pauses in DOS games 🤣