Compaq 7790DMT compact flash adapter problems
Posted by Zander-Sans@reddit | vintagecomputing | View on Reddit | 5 comments
Hi, I have a Compaq 7790DMT and I'm trying to use CF cards as a storage solution. When I do this however, I get weird errors. After formatting the drive (with either a modern computer or the MS DOS format tool) some letters in the volume name are off. In the image of this post, the volume name is supposed to be "COMPAQ" but instead it's "CNMPAP".
Googling around says it could be the adapter I'm using, but I don't know where I would obtain a "better" adapter. It's a 44 pin IDE to CF card adapter. Adapter link.
Really unsure where to go from here. Any suggestions? Thank you in advance to everyone who trys to help.
Red_Redditor_Reddit@reddit
You might need to format inside the device itself. I had similar trouble. I think the problem comes from the new hardware seeing the cf card logically, while the old hardware sees it in terms of cylinders and heads. It will work, but it just won't be able to swap between the old and newer hardware, and you'll need to send over data some other way.
LXC37@reddit
That's probably data corruption happening somewhere...
I'd start with checking the card in modern system as it is the easiest thing to do...
Tokimemofan@reddit
It’s interesting that both incorrect letters involve a bit flip from a 1 to a 0 on the 8th bit if you look at ascii to binary table. I would say the odds of that being a coincidence are pretty low, something has a stuck bit here or did at some point
LXC37@reddit
That's interesting. May be worth checking RAM also, however unlikely to cause issues in specific place every time - this is always a possibility.
Flash, on the other hand, is probably too complex to cause an issue like this. Though IMO still worth checking...
Tokimemofan@reddit
Does the drive model show correctly in the bios? I have seen similar errors where a Toshiba drive will come up as Poshiba etc. if you see similar then check your connections, this is caused by an open or shorted data line causing a single bit to always be 1 or 0. The incorrect letters here, O>N and P>Q both involve flipping the 8th bit from a 1 to a 0.