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Confusion over tape drives and their controlles

josephdaniel

Experienced Member
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Jul 3, 2012
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Florence, Texas, United States
I have two 120MB Colorado tape drives here that use a card edge connector. I have read online that these can be connected to a regular floppy controller and you use the back up software and that's it. Is that right? I don't see how it would work considering the original IBM controller is limited at 720k and the tape drive holds 120 MB?
 
That sounds right, based on my experience using Quarter-Inch Cartridge tape drives.

I think the tape drives will read files off of secondary storage, such as a hard drive and then take advantage of the floppy DMA channel to transfer bytes to the tape drive as quickly as it can (If I remember correctly, that's the main reason to use the floppy connector in the first place!). The drive/software never holds 120MB anywhere at one time.
 
The limitation on the floppy controller (the original IBM) is the data rate - 1.44 and 1.2 drives deliver data at twice the speed of 720/360K disks which is where the problem lies. So as long as you're streaming data at 250kbit/s, it really doesn't care what size it is. You wont have any BIOS support of course, so special software is needed.

NB: it's possible that the drive expects to stream at 500kbit, in which case you'd have an issue and need to upgrade to a slightly more modern FDC. If it's a 3.5" style QIC drive, it will have been designed for something a lot newer (Pentium etc). In that era people usually had floppy drive cables with spare edge connectors hanging off not being used - perfect for a tape drive to piggy back off ;)
 
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Floppy tapes are kind of the "budget" end of quarter-inch tapes. They can't be read by the higher-priced tape drives that use QIC02, QIC36 or SCSI interfaces. Essentially, they use the floppy controller to format, write and read back data in a "sort of" floppy format.

One aspect that can get nasty is that they don't do "read after write" verification. So if your tape has an error, you don't know it until to make another pass over the tape to verify it. And then, if there's an error, you have to start the process all over again. Whatever you do, don't get rid of the drive if you ever hope to recover the data that you've written--floppy tape formats aren't necessarily identical.

If you're really interested in quarter-inch tape, you might want to look at some of the SCSI-interface models. They're not expensive and they're pretty reliable, as long as the tape holds out. (Quarter-inch cartridges are beginning to develop age-related issues).

You can also find ISA floppy-tape "accelerator" cards that can transfer data at 1Mbit/sec. and don't tie up your floppy controller.
 
Thanks Chuck,
I am just going to use it for two things
1. Make a backup about once a month because I don't trust a 25 year old hard drive...
2. to make a copy of my c:\ drive to keep in my portable 8088

Also, does the drive need software to work and save data?
 
You will need to install the Colorado Backup software. There are versions for DOS, Windows 3.1, and Windows 95.

BIOS and DOS will not know anything about the drive without the software. The software talks directly to the floppy disk controller chip and does "special" things to communicate with the tape drive. Even though it uses the FDC, it doesn't treat it anything like a regular floppy drive. It will work with low-density controller cards, but you will get a faster transfer rate with high density controllers. Some of the tape drive models can even make use of 2.88mb controller cards for even more throughput.

Just Google "Colorado Backup for Dos 4.70" or "Colorado Backup System Disks" and that should turn up what you need.
 
Floppy tapes are kind of the "budget" end of quarter-inch tapes. They can't be read by the higher-priced tape drives that use QIC02, QIC36 or SCSI interfaces. Essentially, they use the floppy controller to format, write and read back data in a "sort of" floppy format.

One aspect that can get nasty is that they don't do "read after write" verification. So if your tape has an error, you don't know it until to make another pass over the tape to verify it. And then, if there's an error, you have to start the process all over again. Whatever you do, don't get rid of the drive if you ever hope to recover the data that you've written--floppy tape formats aren't necessarily identical.

If you're really interested in quarter-inch tape, you might want to look at some of the SCSI-interface models. They're not expensive and they're pretty reliable, as long as the tape holds out. (Quarter-inch cartridges are beginning to develop age-related issues).

You can also find ISA floppy-tape "accelerator" cards that can transfer data at 1Mbit/sec. and don't tie up your floppy controller.

My Ditto drive came with a Dash card which made a massive world of difference on the weekly backups.
 
My Ditto drive came with a Dash card which made a massive world of difference on the weekly backups.

Is the rubber on the capstan of your Ditto still intact? (That applies to other tape drives as well. Gooification seems to be the rule on a lot of 80s and 90s tape drives now.)

Personally, I'd trust a Zip drive for use today more than an old tape drive.
 
As one who depended on (and was bitten by) QIC floppy-attached tape drives in the late 90's/early 2000's, I'd recommend not using them for actual backups. I religiously backed up to tape, only to find data loss when I finally had to use the backup. This was using brand-new shrinkwrapped tapes and maintaining a rotation. You're better off backing up to a newer machine via network/parallel/serial connection.
 
I have already got that just trying to be redundant and I will not be adding a network card in my portable that I am getting so it would make moving *large* (a whopping 6MB! :D) amounts of data to that computer
thanks Stone
 
Is the rubber on the capstan of your Ditto still intact? (That applies to other tape drives as well. Gooification seems to be the rule on a lot of 80s and 90s tape drives now.)

Personally, I'd trust a Zip drive for use today more than an old tape drive.

Amen to the goo problem. I've had that on one of my drives recently and on another drive (a 6157) the capstan rubber was just falling apart (it would crumble) at the slightest touch.... I like period specific tech so on my older machines I have QIC-02 drives. On a 386 I have a fdc controlled tape drive (wouldn't mind finding a fast controller) and the 486/Pentium machines have SCSI drives. Anything newer then that has a CD-R.....
 
Is the rubber on the capstan of your Ditto still intact? (That applies to other tape drives as well. Gooification seems to be the rule on a lot of 80s and 90s tape drives now.)

Personally, I'd trust a Zip drive for use today more than an old tape drive.

It's been a few years since I last used my ditto drive and upgraded to DAT, DLT and now LTO. I'll have to check and look.
 
As one who depended on (and was bitten by) QIC floppy-attached tape drives in the late 90's/early 2000's, I'd recommend not using them for actual backups. I religiously backed up to tape, only to find data loss when I finally had to use the backup. This was using brand-new shrinkwrapped tapes and maintaining a rotation. You're better off backing up to a newer machine via network/parallel/serial connection.
Amen! If it's new enough, use a USB stick/drive/SDcard, etc.; if it's too old, connect it to your main computer via RS-232, Ethernet, Bluetooth, IR, direct IDE, whatever, and back it up there.

So what if some solutions are a bit slow; tape isn't the fastest either and you don't have to watch it. Reminds me of a friend's wife who complained that she could do the dishes faster than the new dishwasher and asked him to take it back.
 
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