This message is from the T13 list server.
Originally (in older spec revisions), Word 82 represented the "Supported" flags that indicate whether the feature is even present on the device, and Word 85 represented the "Enabled" flags that indicate if the feature has been enabled through the appropriate Set Features command. Some of the enable flags really didn't have a way to enable or disable them, so in recent specs the affected "Enabled" bits became shadow "Supported" flags. When you do have on/off control the bits should be reacted to by looking at word 82 on deciding whether to enable the feature, then an AND of the two before you attemt to actually use the feature. The same relationship can be extended to words 83/86 and 84/87. For flags that are fixed you can do an OR, but of one is not right when do you know that the feature really exists? I suggest an "AND" relationship for testing the fixed flags. MKE. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of kepler Sent: Monday, May 15, 2006 11:45 PM To: t13-ATA Cc: [EMAIL PROTECTED] Subject: [t13] Should or Shall word82[2] and word85[2] have identical values in IDENTIFY DEVICE response for ATA/ATAPI-6? This message is from the T13 list server. Dear all, On page 125 of ATA/ATAPI-6, clause 8.15.42 says that "if bit 2 of word 82 is set to one, the Removable Media feature set is supported." On page 127 of ATA/ATAPI-6, clause 8.15.43 says that "if bit 2 of word 85 is set to one, the Removable Media feature set is supported." The two bits in the IDENTIFY DEVICE response indicates the same thing. In my recognition, the two bits have an OR relation because they do not say "if the bit is clered to zero, the feature is not supported". Even though they do not say " if the bit is cleared to zero, the feature is not supported". I would like to know whether or not the Removable Media feature set is supported if word82[2]=0 and word85[2]=1, or vice versa? Moreover, as the subject, Should or Shall word82[2] and word85[2] have identical values in IDENTIFY DEVICE response? The same duplication occurs for word83[13:0] and word86[13:0], word83[1:0] and word86[1:0], word 84[5] and word86[5], and word84[1:0] and word87[1:0]. Sincerly Yours, Kepler
