I have been using both CF and SD cards in old pcs. With every single card, in the begining I had problems like yours. I mean, I would set it's parameters in bios correctly, then create partitions and format them. Then I would install dos, and it would not boot. But if I boot using a bootdisk, the card works ok as a disk. First I found out that if I installed the card as a disk in my old 286, and low-level formatted it, using the format disk option in the diagnostics, seemed to solve the problem. Another way I've found, is a small dos utility, called clearhdd.exe . If you use that, it wipes out entirely the disk, and seems to correct that problem. You simply have to copy that file on a bootdisk, and on the dos prompt you need to run clearhdd 0 (or probably 1 if it is your second, slave drive). Then you use fdisk and format again, and it should be ok. Recently I've read that a compact flash card needs to be set to fixed disk rather than to removable. I don't know if this applies to windows only or also in DOS, but maybe that is what this utility or the low level format does.

I got some cheap ones from eBay in 2 and 4 GB sizes. The 4 GB one is a lot faster but not sure if 386 boards have UDMA?

The brand is MEMORETTE I believe...

Thanks a lot for the info! 😀 I'd be really grateful if you could please provide a download link to clearhdd.exe, or just upload it as an attachment. Thanks a lot if possible!

I found sth. See if that works. If not, I have to get it from my win98 startup disk where I'm sure I have it.

edit : While searching for it, I found out it was made by samsung. It was freeware, but I can't find it on their web site right now.

Ive been using the Transcend 133x cards on various machines under dos and I've noticed that they will work fine for a while then randomly get a disk read error, sometimes when running a program but most often during big file copies.

No rhyme or reason to it, if you restart the operation it will usually go through, or sometimes fail at a different point.

I'm keen to try this clearhdd util or a low level format and see if that fixes it.

Sometimes that problem appeared to me also. And I had read and write errors. But it would occur as you say randomly and not always. However I doubt that it is a problem of the card, as it isn't happening on all systems. Maybe it has to do with the controller.

DonutKing wrote:

then randomly get a disk read error, sometimes when running a program but most often during big file copies.

I had this issue on my Super Socket 7 machine. I solved it by using the secondary IDE controller. So maybe give that a go?

Mau1wurf1977 wrote:

I had this issue on my Super Socket 7 machine. I solved it by using the secondary IDE controller. So maybe give that a go?

That's exactly what I did! I used to have a transcend 300x 2gb CF card, as primary master hd, on a soyo socket 7 board. Then I replaced it with a physical disk, which I used only for dos games. I had the cd-rom as slave, and the CF card as secondary master, and there I had windows 98. Then it worked flawless....

btw, it was a pentium 166mmx, with 64MB ram, and it needed just 21-22" to boot windows 98 se.

Markk wrote:

that's exactly what I did!

Fascinating! Maybe we are onto something here...

DonutKing could you try the secondary IDE controller and see if this resolves your issue?

I've had troubles with my Transcend 8 GB 133x CF card before, and I'm still not sure what caused it. There are too many factors involved, especially on my overclocked 486 with an IDE controller that is notorious for bugs.

I never got read/write errors, but the FAT32 filesystems on the card got corrupted twice since use the card. In both cases I had mounted the card in other machines (Win98, Linux) shortly before.

It has worked OK for some time now...

retro games 100 wrote:

What's the safest CF to use, for old 386 and 486 systems? I was hoping for something a bit bigger and faster than my old 128MB CF, but if that's going to be safest CF to use, then I'll have to stick with that.

Seen from a technical standpoint, the 128 MB CF is the one most likely to fail: The maximum number of write/erase cycles on old CF cards is lower than on newer cards, so it will fail sooner. The wear levelling feature is less efficient on old cards, and over the long run, the smaller size invariably results in more write/erase cycles per block, which in turn wears down the card even faster.

As always, you guys provide awesome retro knowledge! Thanks. I downloaded the very useful clearhdd.exe attachment, and it has resolved some problems which I could not overcome. Here's my current 486 set up:

C: = Working CF drive mounted in primary integrated IDE channel 1
D: = Non working CF drive mounted in primary integrated IDE channel 2

I boot up to DOS on C: I then run clearhdd.exe, and wipe the D:\ drive. Many times, this util reports an error, and I simply rerun it until it works without error. After this, I can put the CF from D: in to C:, and then boot up from an A: diskette. I then FDISK and FORMAT drive C:

I've had two problems so far. Problem #1 = one "random" read error occured on my Transcend 133x 2GB drive. Problem #2 = If I FDISK the drive using LBA, MS-DOS refuses to install on to it. It complains about not being able to write to the boot block sector, or something like that. If I switch off LBA, and run FDISK to make the drive only equal to 503 MB in size, all is well, and DOS installs and boots up correctly on it.

I am currently ploughing through all of my CF drives, of all speeds and sizes, and doing the above operation on them all. That includes installing DOS. I'll report back when I've done all of them, with any more issues that I encounter. I have come to the following very "quick and lazy" conclusion - the best size CF to get could be 512 MB, for compatibility concerns on old 386/486 mobos. Also, the clearhdd is a very useful utility.

Edit: I've noticed that the SpeedSys HDD test does not work on one of my CF drives - the 512 MB one. It just freezes. It works on my Transcend 2GB CF however.

Unfortunately, I spoke too soon. 😦 I did manage to correct a problem with one of my 512MB CF drives, but all of the others still won't respond inside my 486 mobo. I've tried the clearhdd.exe utility using the 486 mobo, and also a slot 1 mobo.

Markk wrote:

I found sth. See if that works. If not, I have to get it from my win98 startup disk where I'm sure I have it.

edit : While searching for it, I found out it was made by samsung. It was freeware, but I can't find it on their web site right now.

I tried downloading the file mentioned at the top of this forum post and it didn't quite look the same as the one used on the LGR video where he formats the compact flash card. So after much digging, I found that very same version as well as the documentation which came with it. Enjoy!

I came across this thread via google, while researching how to make cheap CF cards bootable.

To share worked for me / issues I had :
- some better brands like sandisk worked without much effort via an internal cf to ide adapter (I've had good success with 32mb, 64mb, 128mb cf cards from an old camera - the manufacturer date on the sticker is around 2001)
- some cheaper cards from aliexpress (size =512mb, 2gb etc) didnt work as internal bootable hdd even though they were detected in bios and could accessed once the system was booted via floppy.

Solution for me in the end ?
- downloaded Rufus
https://rufus.ie/en/
- plugged in cf card into in win 10 pc (via usb card reader)
- opened Rufus
- selected 'freedos' as the boot selection
- MBR as partition scheme
(There is also an optional setting for old bios if still having issues but I didn't need it)

- Click start
Once finished put back in the 486.

Pretty much all of my cheap cf cards detected in the bios will now boot using the cf to ide adapter.

Example of the cheap cf cards in referring to...

I'm keen to see if I can get dos 6.22 working on one of these cf cards but this will do me for now as I'm keen to make a few bootable dos gaming cf cards.

Hope that helps anyone else who finds this via Google still looking for another way forward.

I personally own some CF cards from 2gb to 8gb.
They all work fine but they are Sandisk, Trascend and Agfa, I use them from 386 with dos 6.22 (the 2gb ones) to socket 7 builds (8gb card).

What about those cheap chinese cards? Do they perform well? I would be worried about writing speed and longevity.

I doubt it in comparison to the better quality brands.

For a cheap and cheerful solution to get a system up and going probably ok.

I was originally using my small 128mb SanDisk as a C: drive and a 2gb cheap one as my drive D:

My 486 system seems to cap out at a 2gb hdd limit so was keen to maximise hdd space.

I just thought to test my sd cards, I used my current pc:

1Agfaphoto 8gb 233x: 
2Seq read: 41,26mb/s
3Seq write: 28,45mb/s
4Random read: 7,28mb/s
5Random write: 0,03mb/s
6
7Agfaphoto 4gb 120x:
8Seq read: 22,02mb/s
9Seq write: 17,78mb/s
10Random read: 7,70mb/s
11Random write: 0,04mb/s
12
13Transcend 2gb 300x:
14Seq read: 58,06mb/s
15Seq write: 20,75mb/s
16Random read: 11,31mb/s
17Random write: 0,07mb/s

I also have a 2gb Agfaphoto 120x but I suppose the performance would be similar to the 4gb.

As always mentioned the main quirk is the writing speed, but for a ms dos build a 120-133x card should be enough, they usually need to be used in pio mode 3 (or 4?) so the peak would be 16,6mb anyway.

What tool did you use I.e. crystal disk - if I get time, I'll test them in my windows 10 machine to see what I get.

I have few of these chinese CF cards. It's getting hard to buy branded ones, most stores don't even sell them any more.

So far I haven't had any issues booting off of them, either on PCs or Amigas. So far most problematic cards I tried were Kingston ones, bought in legit store 4-5 years ago. That one simply wouldn't boot in any computer I tried. Only storage...

As for these chinese cards... from what I've seen about them they're mostly refurbished (or simply relabeled) old cards. One reports as kodak card, other one as Agfa, and so on. My guess is that they only strip original label and slap these on. I think that one of them even has original label underneath. Last two I got on first glance look like those above, but have new, a bit more custom, label. With "manufacturer name on it" and with typo saying "DIGITAL RERORY CARD" 🤣.