This message is from the T13 list server.
James, all, I gotta pipe-in with everyone else. The features that show supported bits, but don't require specific enabling, do not have a Set Features to control it; the feature just works (specific enable flag bit says "supported" instead of "enabled"). If the feature does have an enable indicator, it does have a Set Features to control it. (specific enable flag bit says "enabled" instead of "supported"). A feature such as 48-bit does not need to be enabled, and software needs to check that the support bit is set. I agree with Hale in that a sub 128GB drive (134GB, or 137GB...whatever you like to think a GB is) can very well support the 48-bit command set. As for testing the validity of Id-Drive words 100-103, software must validate these numbers. If the fields don't make sense, the feature shouldn't be used. So basically validating a drive's 48-bit abilities require testing both the appropriate "supported" bit and the "Max 48-bit Address" fields before using 48-bit commands. TTFN, MKE. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Friday, September 27, 2002 7:46 AM To: T13 List Server Subject: Re: [t13] 48BIT Supported Poll This message is from the T13 list server. Is this supported/enabled stuff 'on purpose' ? or is it a long-missed typo ? Some quick research shows that this language began in ATA/ATAPI-4. Thanx !!! ----------------------------------------------------------------- Jim Hatfield ATA Interface Firmware Seagate Technology - PSG e-mail: [EMAIL PROTECTED] s-mail: 389 Disc Drive; Longmont, CO 80501 USA voice: 720-684-2120 fax : 720-684-2711 ==================================================== WHOA! Apply this to setfeatures on write-cache! Just because it is "supported" does not mean it has to be "enabled". There are many other cases where "support" v/s "enable" may clash. I may be off base but not out of the loop. Andre Hedrick LAD Storage Consulting Group On Thu, 26 Sep 2002 [EMAIL PROTECTED] wrote: > This message is from the T13 list server. > > > > >The only question (for me) is whether to CHANGE the wording for words > >100-103 > >from: "is mandatory if the 48-bit Address feature set is supported." > >to: "is mandatory if the 48-bit Address feature set is enabled." > > >>Supported I understand. What do you mean by "enabled"? Isn't > >>this one of those features that is always enabled if it is > >>supported just like 28-bit LBA is always enabled if supported? > > Ahhhh !!! > I never saw that fine point that some of the 'enabled' bits say > 'supported' !!! > Yes. If the feature is 'supported' it shall also report 'enabled' > > Thanx !!! > ----------------------------------------------------------------- > Jim Hatfield > ATA Interface Firmware > Seagate Technology - PSG > e-mail: [EMAIL PROTECTED] > s-mail: 389 Disc Drive; Longmont, CO 80501 USA > voice: 720-684-2120 > fax : 720-684-2711 > ==================================================== >
