Table of Contents
TEAC FD-55 GFV
The TEAC FD-55 GFV has a notably different PCB from its other variants, and does not include the same cross shaped drive speed jumper as literally all of its other iterations. It appears to be targeted as a drop-in replacement for 8“ disk drives.
Specifications
8” disks typically had 77 tracks, while high-density 5.25“ disks had 80 tracks. Because this drive is meant to be a replacement for an 8” drive, the original spec sheet shows the data for both 80-track disks and 77-track disks for FM and MFM write modes. For simplicity, this table shows the data for 80 tracks and assumes that MFM is always used.
| Capacity | Formatted: HD 1.2 MiB; DD 655.36 KiB |
|---|---|
| Unformatted: HD 1.6 MiB; DD 1.0 MiB | |
| Disk size | 5.25“ |
| Heads | 2 |
| Surfaces | 2 |
| Tracks/Surface | 77 / 80 |
| Track density | 96 tpi (tracks/in) |
| Bit density | HD: 9870 bpi; DD: 5922 bpi |
| Record method | FM / MFM |
| Rotation rate | HD: 360 rpm; DD: 300/360 rpm |
| Seek time | Track to track: 3 ms |
| Settle time | 15 ms |
| Data transfer | HD: 500 Kib/s; DD: 250 / 300 Kib/s |
| Power | +5 V, +12 V |
| Power dissipation | 5.2 watts operating, 1.8 W at rest |
Physical specs:
| Height | 1.63 in / 41.3 mm |
|---|---|
| Width | 5.75 in / 146 mm |
| Depth | 7.99 in / 203 mm |
| Weight | 1.2 kg nominal, 1.35 kg maximum |
| Shock rating | Operating: <10 G; |
| Non-operating: <40 G | |
| Vibration | Operating: <0.5 G @ < 55 Hz, <0.25 G @ 55 - 500 Hz; |
| Non-operating <2 G @ 0 - 100 Hz |
(Specifications come from z1013.mrboot.de and have been translated from German.)
Jumper Settings
The following jumper settings are known to work with the Applesauce:
| DCRY | RY | Disk Change/Ready on line 34* |
|---|---|---|
| DS0 | Connected | Drive select (any drive number is fine) |
| DS1 | Not connected | |
| DS2 | Not connected | |
| DS3 | Not connected | |
| U1 | Not connected | Head load on motor on |
| U2 | Connected | |
| HL | Not connected | Pin 4 is Head Load |
| IU | Not connected | Pin 4 is In Use |
| LG-HG | HG (both!) | Sets High Density input level |
* ⚠️ Make a note of the original setting if you change the DCRY jumper! See DISK CHANGE/READY for a more thorough explanation.
