Sider/ SASI Info

["Paul Grammens" <grammens@svn.net>]

I'm putting together some info on Sider hard disks for the Apple II.
Seems like the cables and terminators are commonly missing, so here is the
info needed to make your own cable from the Xebec interface card to the rear
panel, and the terminator which attaches to the Sider drive.

I found most of this on the net, and took apart my terminator to
reverse-engineer it.
The only piece of info I'm missing is the DB37 to DB37 cable that goes from
the rear panel of the Apple II to the Sider drive.  Comparing the terminator
to the ribbon cable, it does not appear that it is a straight-thru cable.

If anyone has anything to add to this, please post it.
-Paul



Materials:  SCSI ribbon cable  with header, 50 conductor. DB-37 female
connector.

37 pin   2x25 pin
D-Sub      header

 1 ->  1
 2 ->  3
 3 ->  5
 4 ->  7
 5 ->  9
 6 -> 11
 7 -> 13
 8 -> 15
 9 -> 17
10 -> 19
11 -> 34
12 -> 36
13 -> 38
14 -> 40
15 -> 42
16 -> 44
17 -> 46
18 -> 48
19 -> 50
20 ->  2
21 ->  4
22 ->  6
23 ->  8
24 -> 10
25 -> 12
26 -> 14
27 -> 16
28 -> 18
29 -> 20
30 -> 35
31 -> 37
32 -> 39
33 -> 41
34 -> 43
35 -> 45
36 -> 47
37 -> 49

Source: Sider Fixed Disk Drive Subsystem User's Guide 106109-01 Rev. D

Also note that the drive needs a terminator plug on one of the two
ports on the back of the external drive. I tried, and I can't get my
drive to work without one.
******************************************
Sider Terminator construction:
Male DB37 connector. Twelve 140 Ohm resistors, or resistor pack.
140 ohm resistors, common pin is 29.
Other end of resistors to pins 1, 13, 14, 16, 20-27.


*****************************************
This is from an Atari Xebec interface, but seems to be the same as the Apple
II Xebec.

Table 2-3. Standard SCSi/SASI Signals
 Direction Description Abbv Pin Notes
 both Data bit 0 -DB(0) 2
 both Data b~t 1 -DB(l) 4
 both Data bit 2 -DB(2) 6
 both Data b~t 3 -DB(3) 8
 both Data bit 14 -DB(14) 10
 both Data bit 5 -DB(5) 12
 both Data bit 6 -DB(6) 14
 both Data bit 7 -DB(7) 16
 both Parity bit -FAR 18 N/C -- not supported
 from MIO Attention -ATN 32 N/C -- not supported
 to MIO Bus Busy -BSY 36
 from MIO Acknowledge -ACK 38
 from MIO Bus Reset -RST 40
 to MIO Message phase -MSG 42 Connected, not supported
 from MIO Select Target -SEL 44
 to MIO Command or Data -CID 46
 to MIO Request Data -REQ 48
 to MIO Input or Output -I/O 50