DIGITAL-LOGIC MICROSPACE MSM286 Series Technical User's Manual page 21

DIGITAL-LOGIC AG
The desired configuration of floppy drives (number and type) must be properly initialized in the
board's CMOS - configuration memory. This is generally done by using ALT + 'S' or F2 at bootup
time.
Floppy interface connector
The table shows the pinout and signal definitions of the board's floppy disk interface connector. It is
identical in pinout to the floppy connector of a standard AT. Note that, as in a standard PC or AT, both
floppy drives are jumpered to the same drive select: as the 'second' drive. The drives are uniquely
selected as a result of a swapping of a group of seven wires (conductors 10-16) that must be in the
cable between the two drives. The seven-wire swap goes between the computer board and drive 'A';
the wires to drive 'B' are unswapped (or swapped a second time). The 26pin high density (1mm pitch
FCC) connector has only one drive and motor select. The on-board jumper defines the drive letter A:
or B:. Default is always A:.
The 34 pin Connector:
The 26 pin Connector:
Floppydisk Interface Connector
FD34: FD26:
Pin Pin
2
4 ---
6 ---
8 2
10
12 4
14
16 10
18 12
20 14
22 16
24 18
26 20
28 22
30 24
32 26
34 6
1-33 25,23,21,19,17
1,3,5
Ribbon 1,27mm IDT dual row terminal with 2.54mm grid
FFC/FPC 0.3mm thick 1.0mm (0.039") pitch (MOLEX 52030 Serie)
available on MSM286, MSM3/486
Signal Name
-RPM/-RWC
(Not used)
(Not used)
-IDX
-MO1
-DS2
-DS1
-M02
-DIRC
-STEP
-WD
-WE
-TRKO
-WP
-RDD
-HS
-DCHG
GND
VCC
Function
Speed/Precomp (option)
Index Pulse
Motor On 1
Drive Select 2
Drive Select 1
Motor On 2
Direction Select
Step
Write Data
Write Enable
Track 0
Write Protect
Read Data
Head Select
Disk Change
Signal grounds
+5 Volt
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MSM286 Manual V6.4
in/out
out
in
out
out
out
out
out
out
out
out
in
in
in
out
in