Commodore Amiga - Page 286

EXTERNAL DISK CONNECTOR IDENTIFICATION KIDB
An identification mode is provided for reading a 32-bit serial
identification data stream from an external device. To initialize
this mode, the motor ImlSt be turned on, then off. See pin 8,
MTRXD* for a discussion of how to turn the motor on and off. The
transition from motor on to motor off reinitia1izes the serial
shift register.
After initialization, the SELxB* signal should be left in the
inactive state.
Now enter a loop where SELxB* is driven active, read serial input
data on ROY* (pin 1), and drive SELxB* inactive. Repeat this loop
a total of 32 times to read in 32 bits of data. The most significant
bit is received first.
EXTERNAL DISK CONNECTOR DEFINED IDENTIFlCA.TIONS
$0000 0000 - no drive present.
$FFFF FFFF - Amiga standard 3.25 diskette.
$5555 5555 - 48 !PI double-density, double-sided.
As with other peripheral IO's, users should contact Commodore-Amiga
for 10 assignment.
The serial input data is active low and must therefore be inverted
to be consistent with the above table.
EXTERNAL DISK CONNECTOR LIMITATIONS
1. The total cable length, including daisy chaining, must not exceed
1 meter. .
2. A maximum of 3 external devices may reside on this interface.
3. Bach device must provide a 1000-Ohm pull-up resistor on those
outputs driven by an open-colleCtor device on the Amiga
(pins 8-10, 16-21).
•••••••••••••• PART 3 - INTERNAL CONNE~ ••••••••••••• **.***
DISK INTERNAL ••. 34 PIN RIBBON (J10)
1
GND
18
DIRB
2 CHNG*
19 GND
3 GND
2e STEPB*
4 MTROD* (led)
21
GND
5 GND
22 DKWDB*
6 N.C.
23
GND
7 GND
24
DKWEB*
8 INDEX*
25
GND
9
GND
26 TKO*
10 SELOB*
27 GND
11 GND
28 WPRO*
12
N.C. 29
GND
13 GND
30
DKRD*
14
N.C.
31
GNr
15 GND
32
SIDEB·
16 MTROD*
33
GND
17 GND
34 ROY*
DISK INTERNAL POWER ••• 4 PIN STRAIGHT (J13)
1
+12
2 GND
3 GND
4
+5