Gaming Replacing magnetic storage in a DOS retrogaming machine

Linguofreak

Well-known member
Joined
May 10, 2008
Messages
5,017
Reaction score
1,254
Points
188
Location
Dallas, TX
I have a 1995-vintage PC that I use for retrogaming / general retrocomputing. The current configuration has Dos 6.22 / Win3.11, Win95, and Debian 4 squeezed onto an 4 GiB IDE spinning-rust disk. I have ambitions to move it all to a larger disk to give Win95 and Linux some more room (DOS, as I recall, is stuck in the bottom 512 megs due to BIOS limitations, while Win95 and Linux do their own disk I/O). I had a 120+ GiB IDE disk, but, unfortunately, the aforementioned BIOS limitation causes the BIOS to refuse to recognize large disks as present, unless, when a new disk is first presented to it, all partitions on the disk are within the bottom 512 MiB. So after transferring the data to the new disk on a separate machine (there's only room for 1 HDD in the old machine), I then had to back up the boot sector, delete all the partitions but the DOS one (which fits within 512 MiB), take the drive back to the old machine and boot with the drive present, then take it back to the new machine to overwrite the boot sector with the backup. I got a bit too lazy on the last step: I left the drive screwed to the drive tray from the old machine and balanced that precariously in the case for the "new" machine (which is still old enough to have IDE :) ). It didn't fall over, but I think this didn't do enough to suppress vibration, because the drive started parking and unparking its heads repeatedly (judging by the noise) and stopped responding to the computer. So now I don't have a drive in the size range I want that actually works.

So now I'm looking to future-proof the machine a bit by using compact flash for storage, which seems to be popular for replacing IDE drives on aging hardware. Unfortunately, while it seems to work if you buy the right adapters and CF cards, there seem to be quite a few caveats as far as ensuring card <-> adapter <-> motherboard compatibility, and not a lot of concrete advice on what to buy, what to avoid, etc. This isn't an urgent project (it's not a vital machine and the 4 GiB drive I was trying to move off of should still work), but I really -would- like to get it done.

Is there anyone here that:

A) Is into retrogaming/retrocomputing on DOS-era hardware
B) Has used CF <-> IDE adapters on said hardware
C) Can provide advice?

A few more details on my hardware situation and goals:

1) The machine has 3 drive bays, 1 3.5" and two 5", of which the 3.5" inch and one 5" bay are in use (floppy and CD drive).
2) In its current pulled-apart state with no HDD attached, the machine has 3 free IDE connectors (one connector on the secondary cable is used by the CD drive). From the size of CF <-> IDE adapters I've seen on the web, I think I should be able to fit three of them into the free 5" bay, which would let me separate the Debian install that I use to administer the machine (e.g, bringing files in over the network) out onto its own storage device (or devices, see below). It would be really, really nice if I could get all three to adjoin the front wall of the bay, so that I could access all three without having to open up the case, but the adapters I've seen that are meant to be mounted with access to the case exterior are either meant for back-panel PCI slots or, if they are meant to mount at the front panel, have a bracket meant to fit into a 3.5" bay, which would prevent me mounting them side by side, which the dimensions of the cards themselves allow. With the proper attachments, I think I could mount them 2 wide by 2 high in the 5" bay, with a blanking plate in place of a fourth card slot (because I only have three connectors open), but the available means to mount them probably mean that, at best, I'll be able to get one mounted with access to the front panel, with the other two stuffed into the back of the bay.
3) The debian installation on the machine is very swap-dependent. It's performant enough as long as I keep to the command line (or possibly to very lightweight X11 setups), but it guaranteed would not run without a swap partition. The problem with this is that (a) any kind of flash memory runs into trouble with being written to as heavily as will happen with swap, and (b) I've heard bad things specifically about the performance of CF cards with the access patterns typical of swapping. I could just use CF for the actual DOS/Win95/Linux installations and retain the existing magnetic disk as a swap device, but that will eventually fail and likely won't be replaceable, and it will absolutely prevent the CF cards from being mounted with front panel access. If I use CF for swap, I'd probably have to dedicate a CF card to it to avoid pounding an "important" disk with too many writes, and at least that card would have to have front panel access, because I'd probably be replacing it fairly often. What would be really nice would be some kind of IDE<->DIMM adapter so I could have volatile RAM as backing store (though then I'd have to run mkswap early on on each boot). In any case, it looks like I'd have a dedicated device for swap, probably with a fair bit more space than actually necessary. It would be nice to get some advice on this point specifically.
4) I thought it was potentially problematic that most CF<->IDE adapters seem to use floppy power connectors for power, but I only have one such connector on this machine, which is in use, while I have three free HDD molex connectors. But on further examination, the two connectors deliver the same voltages (+12, +5, and two ground), and adapters between the two do seem to exist, so it seems to be a minor issue.

Any thoughts?
 

jedidia

shoemaker without legs
Addon Developer
Joined
Mar 19, 2008
Messages
10,842
Reaction score
2,105
Points
203
Location
between the planets
Honestly, my advice in the days when this would still have been a common computer, would have been "get a bigger case and mount additional drives".
I had quite a bit of experience of tinkering with the hardware you speak about, but unfortunately not of pairing it with modern day tech. I was quite glad when progress slowed down enough that I didn't have to treat my computer like my dirt bike anymore...

Also, I'm fairly confident that harddrive was already damaged, or has been handled roughly in between. I've operated lots of disks that weren't screwed in, I never had one take damage from it...
 

Linguofreak

Well-known member
Joined
May 10, 2008
Messages
5,017
Reaction score
1,254
Points
188
Location
Dallas, TX
Honestly, my advice in the days when this would still have been a common computer, would have been "get a bigger case and mount additional drives".
I had quite a bit of experience of tinkering with the hardware you speak about, but unfortunately not of pairing it with modern day tech. I was quite glad when progress slowed down enough that I didn't have to treat my computer like my dirt bike anymore...

Also, I'm fairly confident that harddrive was already damaged, or has been handled roughly in between. I've operated lots of disks that weren't screwed in, I never had one take damage from it...

I've operated disks that weren't screwed in, but pretty much flat on the bottom of the case. This was screwed into a tray that didn't fit neatly in the case and was precariously balanced such that I was a bit afraid that it would slip and fall. I think what happened was that it had a bit of freedom of movement with not enough contact area to provide adequate friction, and things like head movement and forces associated with drive rotation were able to set up some amount of vibration.
 
Top