[. . . ] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ST9235 Family: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ST9235 Family Product Manual ST9080A, ST9145A, ST9145AG ST9235A, ST9235AG AT Interface Drives 36206-001, Rev. B Seagate®, Seagate Technology®, and the Seagate logo are registered trademarks of Seagate Technology, Inc. Other product names are registered trademarks or trademarks of their owners. [. . . ] ST9235A and ST9235AG mounting dimensions (non-MCC mounting version) ST9235 Family Product Manual, Rev. B 19 3. 0 ATA interface The ST9235 family drives use the industry-standard ATA task file interface. The drives support both 8-bit and 16-bit data transfers and have no DMA capability. Refer to the Seagate ATA Interface Specification, publication number 36111-001. Up to two drives can be daisy-chained (assigning master and slave drives) on the same host bus. 3. 1 Drive configuration 3. 1. 1 Master/slave selection A master/slave relationship must be established between drives on the AT bus using the drive jumpers. Drive 1 is configured as the master and Drive 2 is configured as the slave. Refer to the table below and Figures 9 through 11 on pages 20 through 22 for user-configuration jumper settings to configure a drive as a master or a slave. Jumper for pins A and B Removed Removed Installed Installed Jumper for pins C and D Removed Installed Removed Installed Configuration Drive is master; no slave drive present Drive is master; Seagate slave drive present Drive is slave; Seagate master drive present Reserved position--do not use 3. 1. 2 Remote LED The drive indicates activity to the host through the DASP­ line (pin 39) on the ATA interface. This line may be connected to a drive status indicator driving an LED at 5V. The line has a 30 mA nominal current limit. 20 ST9235 Family Product Manual, Rev. Drive is shown with circuit board up. Master/slave Pin 1 configuration jumpers Pin 20 removed for keying Circuit board B A D C Drive is master; no slave present Drive is master; Seagate slave drive present Drive is slave; Seagate master drive present Reserved positions (do not use) Figure 9. Drive is shown with circuit board up. Master/slave Pin 1 configuration jumpers Pin 20 removed for keying Circuit board B A D C Drive is master; no slave present Drive is master; Seagate slave drive present Drive is slave; Seagate master drive present Reserved positions (do not use) Figure 10. ST9145A and ST9145AG connector setup 22 ST9235 Family Product Manual, Rev. Drive is shown with circuit board up. Master/slave Pin 1 configuration jumpers Pin 20 removed for keying Circuit board B A D C Drive is master; no slave present Drive is master; Seagate slave drive present Drive is slave; Seagate master drive present Reserved positions (do not use) Figure 11. ST9235A and ST9235AG connector setup ST9235 Family Product Manual, Rev. B 23 3. 1. 3 Onboard drive diagnostics At power-on, the drive executes a series of diagnostic tests. Error codes (LED flashes) 1 2 3 5 6 Drive error condition Microprocessor error ROM checksum error ATA interface chip failure External RAM error Buffer RAM error 3. 2 ATA bus signal levels Signals driven by the drive have the following output characteristics at the drive connector: Logic Low Logic High 0. 0V to 0. 4V 2. 5V to 5. 25V Signals received by the drive must have the following input characteristics, measured at the drive connector: Logic Low Logic High 0. 0V to 0. 8V 2. 0V to 5. 25V 3. 3 ATA interface cable Maximum cable length is 18 inches (457 mm). It is recommended that the connectors be keyed by inserting a plug into the pin-20 location of the female interface connector. 3. 4 ATA interface connector The drive connector is a 44-conductor connector with 2 rows of 22 male pins on 0. 079-inch (2 mm) centers (see Figure 12 on page 24). The mating cable connector is a 44-conductor, nonshielded connector with 2 rows of 22 female contacts on 0. 079-inch (2 mm) centers. It is recommended that the connectors be keyed by inserting a plug into the pin 20 location of each interface connector. Strain relief is recommended. 24 ST9235 Family Product Manual, Rev. B Some ST9235A and ST9235AG drives and all ST9145A and ST9145AG drives are designed to support the industry-standard MCC direct-mounting specifications. [. . . ] BBH = 4 bytes of ECC apply on Read Long/Write Long commands (default). (1F2H) 1 0 1 D/S X X Bit 7 1 Bit 6 1 Bit 5 1 Bit 4 0 X X X Bit 3 1 Bit 2 1 Bit 1 1 Bit 0 1 ST9235 Family Product Manual, Rev. B 37 Features (1F1H) Set Features parameter 38 ST9235 Family Product Manual, Rev. B 3. 5. 9 Active Immediate (F9H) This command causes the drive to enter Active mode immediately. [. . . ]