Floppy Disk Drives / Shugart 860 / Info


Technical specifications

Formfactor 8"
Capacity 1.155 KByte / DSDD / (2 x 77 x 15 x 512 = 1.182.720 Byte)
Sides (Heads) 2
Tracks/Side 77
Sectors/Track 15
Byte/Sector 512
Height 57 mm


Interface Shugart (50 polig)
Power supply +24V / +5V
Plug 5 pin (1-480763-0; 6,35mm; Manufacturer: TE Connectivity)

Signal lines

The connection of the PC-34 cable with the Shugart-50 ribbon cable is made using two clamp bridges and a variety of screw bridges. The following illustration shows only the even signals. All odd signals are ground; DC ground (GND). See also picture 3.

In principle, the signal TG43 (TRACK GREATER 43, WRITE CURRENT LOW) also appears on the Shugart 860. The drive is already so new that it also allows internal support via jumper and the external line no. 2 is not needed. But this is not true for all 8" drives.

Other drives with an internal TG43 jumper are the Tandon 848-1E and 2E (1983) - please do not confuse it with the 848-1 or 2 (1982) - and the Mitsubishi M2896-63-02M.

Interface PC-34 zu Shugart-50
Interface PC-34 to Shugart-50 with the help of screw bridges

It can be seen in the table that signal 34 (PC-34) is connected to both signal 8 and 12 (Shugart 860). However, this does not work on my Mitsubishi M2896-63-02M. Here is ONLY 34 connected with 12! This is the clear advantage of the screw bridges.

With the help of the terminal blocks and the screw bridges, the floppy can be connected both as drive A: or B :. For A: PC-34 (10) must be connected to Shugart-50 (18), for B: line 16 to 18. Analog is for DS1.

If you want to use two drives, then you have to put on the 34p floppy cable a so-called branch connector. Previously, the tape drives were connected to the floppy controller in this way.

The basics for connecting an 8" drive are described here.


The most important copies are listed below.