05/20/08: Wanted: half height floppy by sc, | Category: Classifieds | 8 comments - (Comments are closed)

Wanted: half height floppy

I have a 501 disk and controller, and the drive looks like the standard half-height in the bottom of the case, and a blank panel above. I would like to slip another drive in there… it looks like the ribbon cable sort of sneaks in the back between the back of the case and the top surface, that must be “normal.”

Anyway, I’d be interested in a half height drive that I could just slide in there. I’m assuming that if I opened it up, I would see an extra connector on the ribbon cable. I don’t know if that’s true, so maybe I should take a look.

Anyway, a drive or even advice would be welcome. Thanks!

-sc

8 comments to Wanted: half height floppy

  • DarrenA

    Yes, there is another connector on the cable inside the enclosure. Both of the connectors use the standard Tandy method for drive selection (pulled teeth), so be prepared to deal with this issue.

    Another option to consider is adding a 3.5 inch drive rather than another 5.25 inch. That’s what what I did with my 501.

  • navydave

    You’ll find that the connectors arent spaced out very far on the cable. If you find a spare drive that has the connector on the opposite side of the other drive thats in there, you may need to order a longer cable from Cloud9. I installed 2 drives in mine and the connectors are on opposite sides of each drive, 2 different brands. The stock cable wouldnt work for me. Cloud9 has extra long custom made cables that have the connectors spaced further apart, and will work.

  • sc

    DarrenA above mentions it is possible to hook up a 3.5″ drive. How is that done, is there an adapter of some sort that is easy to find/build?

    -sc

  • DarrenA

    DarrenA above mentions it is possible to hook up a 3.5″ drive. How is that done, is there an adapter of some sort that is easy to find/build?

    -sc

    Bay adapters with a bezel and power converter are readily available on eBay:

    [url]http://cgi.ebay.com/BLACK-DRIVE-BAY-ADAPTER-BRACKET-3-5-to-5-25-ZIP-FLOPPY_W0QQitemZ180245141077QQihZ008QQcategoryZ167QQssPageNameZWDVWQQrdZ1QQcmdZViewItem[/url]

    A floppy connector adapter is more dificult to find. One source is:

    [url]http://www.jdr.com/interact/item.asp?itemno=DRIVE-EDGE[/url]

    Of course, you can also get some ribbon cable and connectors and build your own.

  • sc

    Thanks for the links, that little adapter looks like it’ll save a lot of effort. Do you think this works with any modern 3.5 drive, or are the current high density drives somehow incompatible?

  • DarrenA

    Modern High-Density drives work fine with the CoCo so long as you use Double-Density media in them. See the discussion in this forum:
    [url]http://www.coco3.com/modules.php?name=Forums&file=viewtopic&t=630[/url]

    The biggest problem you will probably have is the Drive Select issue. The existing connectors on the FD-501 cable have contacts removed from each of them such that only one particular select line reaches the drive. Most modern floppy drives for PCs are hard-wired to respond as Drive 1 (instead of Drive 0). If you want the 3.5 drive to be Drive 1 then this isn’t a problem.

    Also, as navydave mentioned, the two internal connectors are pretty close together and the second one will almost certainly not reach the 3.5 drive. This is one reason why I decided to build my own cable with a card-edge connector for the 5.25 drive and an IDC socket for the 3.5 drive, eliminating the need to buy that little adapter.

  • sc

    I have a couple of those little adapters (url in previous posts) on order, since I’m not very practiced making cables. And you are right, there is not enough cable inside the case to make it from one to the other.

    But I have another disk system, which is a single full-size drive (can’t part with that, don’t see the full heights too often anymore), and the cable is set up for two seperate drives. So there is a good 8 inches between the two connectors. I’m going to swap that cable for the one that is built into the half-height case, use my little adapter when it comes, and away I go. Theoretically.

    Actually, the only bit of this I don’t understand is that I can’t believe that throughout the evolution of floppy drives up to 3 1/2, that the pinouts and capabilities are still backward compatible enough that this thing will actually take off on a coco. But I hope so!

    Thanks for all the input everyone,

    -sc

  • DarrenA

    Actually, the only bit of this I don’t understand is that I can’t believe that throughout the evolution of floppy drives up to 3 1/2, that the pinouts and capabilities are still backward compatible enough that this thing will actually take off on a coco. But I hope so!
    -sc

    This was one area where Tandy did the right thing. They designed their controllers to mate directly with floppy drives using the standard Shugart interface. Modern PC drives use nearly the same interface, with the addition of Disk Change and Density Select lines and replacing the third Drive Select with a separate Motor On control for the second drive. Getting the Drive Selects connected properly is the only real issue you may have.

    CoCo controllers employ a minimal interface (lines for Disk Change, Drive Ready and Density Select are not connected). The one deviation in Tandy drives is the use of the Side Select (or Head Select) line as a fourth Drive Select. This actually turned out to be a benefit, since it allows Tandy controllers to work with double-sided drives through software modifications.