HP 220mx HP SureStore 1200mx/2200mx Optical Jukebox User's Guide - Page 97

Appendix B, The SCSI Bus and This Jukebox

Get HP 220mx PDF manuals and user guides View all HP 220mx manuals
Add to My Manuals
Save this manual to your list of manuals

Page 97 highlights

Operating This Jukebox on a SCSI Bus The SCSI Bus and This Jukebox Operation on a SCSI Bus Because a narrow device only has a 50-pin connector, it will not transmit the eight extra bits of data needed for the wide device on the end of the bus. Using only 50 lines also prevents the narrow device from passing along the IDs of devices at 8 or above. The lower eight data lines transfer commands and messages, allowing all devices, regardless of size, to co-exist on the bus. However, data transfers and device addressing occur on the higher bits. Since a narrow device can't "see" the upper 8 data bits, that translates to it not being able to "see" wide devices with a SCSI ID above 8. Remember the host adapter is a device, so if you're mixing wide and narrow devices on the bus, your host adapter must be at an ID that all devices can address. If mixing narrow and wide devices is unavoidable, use the configuration described below: Appendix B B- 9

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
Appendix B
B-9
Operating This Jukebox on a SCSI Bus
The SCSI Bus and This Jukebox
Operation on a
SCSI Bus
Because a narrow device only has a 50-pin connector, it will not transmit the eight
extra bits of data needed for the wide device on the end of the bus. Using only 50
lines also prevents the narrow device from passing along the IDs of devices at 8 or
above.
The lower eight data lines transfer commands and messages, allowing all devices,
regardless of size, to co-exist on the bus. However, data transfers and device
addressing occur on the higher bits. Since a narrow device can
’
t "see" the upper 8
data bits, that translates to it not being able to "see" wide devices with a SCSI ID
above 8. Remember the host adapter is a device, so if you
’
re mixing wide and
narrow devices on the bus, your host adapter must be at an ID that all devices can
address.
If mixing narrow and wide devices is unavoidable, use the configuration described
below: