Wire up a drive¶

This page connects a QIC-117 floppy-tape drive to the Greaseweazle and gets the drive listening. A floppy-tape drive uses the same 34-pin cable as a floppy drive, but it is commanded by pulses on the STEP line and answers on TRK0, so selecting it works differently from a floppy drive. The protocol is summarised in QIC-117 command interface.

Prerequisites¶

• A Greaseweazle v4.1 running the Tapewyrm firmware (Flash the Greaseweazle).
• A 34-pin floppy cable.
• A PC power supply, or a bench supply with 5 V and 12 V outputs and a 4-pin floppy-drive power connector.
• The drive's page under Drives, if there is one.

Connect the drive¶

1. Connect the drive to the Greaseweazle's 34-pin header with the floppy cable, pin 1 to pin 1. Pin 1 is usually marked by a red stripe on the cable and a small 1 or a square pad on each connector.

   Put one drive on the cable. Phantom-select drives on a shared cable can interfere with each other; see Drive selection.

2. Connect the drive to the external supply's 4-pin power connector.

3. Connect the Greaseweazle to the host over USB.

4. Switch the supply on.

5. Check the board with tw info.

   tw info
   

   You should see the firmware line with a protocol version. If not, see Flash the Greaseweazle.

6. Wake the drive and check it is listening.

   tw drive select
   

   status : 0x25 [ready cartridge_present referenced]
   select : yes -- cue INDEX every 2.9 ms
   

   (Example output.) select : yes means the drive is selected and ready: a selected, ready drive pulses its INDEX line every few milliseconds. If tw stops with no drive answered auto-detection, see The drive does not answer.

Drive selection¶

A floppy controller selects a drive by asserting one of the drive-select lines on the cable. Many floppy-tape drives do not use those lines. tw wakes the drive with a drive profile, which says how the drive expects to be selected. The default profile, auto, tries the four wake-ups the Linux ftape driver tries, in ftape's order, and keeps the first one the drive answers. Profiles are listed in Drive profiles.

Apart from the Motor-on wake, tw releases every drive-select line before it talks to the drive, and again at the end of every command.

Phantom drives stay selected¶

A drive selected with Phantom Select stays selected after tw exits. It stays selected until you run tw drive deselect, the drive is reset, or you switch its power off. Two consequences:

• The second tw command after a cold start usually reports drive answered default. The drive was still listening from the first command, so auto's first try, which sends nothing, got an answer. This is expected; default has the same timings as colorado.
• Two phantom drives on one cable can both be selected at once. Run tw drive deselect before you switch to the other drive, or keep one drive per cable.

The Colorado drives and the TEAC answer at unit address 0. To try another address, run tw drive select --unit N. See tw drive.

Choose a profile¶

auto works for the tested drives. Name a profile when you know the drive, when auto picks the wrong one, or when the drive needs one auto never tries (teac, conner, iomega, or your own file). Put the profile before the subcommand:

tw --profile colorado drive status

To set it once, put it in the config file (~/.config/tapewyrm/config.toml):

profile = "colorado"

See Configuration and logging.

Next steps¶

• Read a tape.