The CIA World Factbook 1992

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HOW TO GET THE BEST PERFORMANCE FROM THE ST225/WD COMBINATION The information contained in the other two files (WD.DOC & WDCONFIG.DOC) provides the technical information necessary to get a hard disk up and running. I changed some of the examples to be specific to the Seagate ST225 20 Meg hard disk and the Western Digital Controller, WD1002S-WX2. When performing the debug low level format this controller will respond with "WX2 Format Revision T.8...", if you get "WX2 Format Revision 6..." you have an older version and will need to get a new EPROM with the T.8 software to maximize the performance of the ST225. My ST225 was slow, and relatively speaking, still is. I had the older EEPROM so I could make no set up changes and it had a CORE test(ver 2.7) performance index of .744. Changing the EEPROM and using two values different from the initial factory specs allowed me to get a performance index of 1.377, an 89% improvement!! There was only a relatively minor increase in seek time from 95.7 ms to 84.2 ms (the ST225 is rated at 65ms so mine is still a dog in this area), but the data transfer rate improved from 28.4 KB/sec to 121.7 KB/sec! The two areas I modified where the interleave factor from the recommended 3 to 4 and the CCB option byte (step rate) from 05 to 07. This combination proved to provide the best performance after many complete formats were tested. I tried interleaves of 3,4 and 5 combined with CCB values of 00, 03, 05 and 07. 00 formatted ok but hung up during the Core test and 03 and 07 provided the same results. I have heard somewhere that Western Digital had recommended the 07 combination so it is the one I use. I normally run my XT Turbo clone at 8MHz and with a "buffers=24" in my config.sys file as well as LIGHTNING installed for the C drive with a cache size of 128K and it is this setup that generated the following numbers from the PC MAGAZINE benchmark test, version 4. (512 bytes/512 records) OLD NEW Sequential file creation: 11.10 sec 11.20 sec " " writing: 14.34 " 9.12 " " " reading: 12.25 " 6.92 " Random " write: 14.01 " 10.21 " " " read: 5.11 " 5.06 " (4K bytes/64 records) OLD NEW Sequential file creation: 10.88 sec 5.05 sec " " writing: 9.95 " 4.07 " " " reading: 12.96 " 5.00 " Random " write: 5.22 " 3.02 " " " read: 6.87 " 3.35 " Reading 1000 random sectors: 167.14 msec 119.79 msec 1000 seeks - sequential: 21.31 msec 21.25 msec " " - random: 96.83 " 85.79 " I hope that this and the other two files are helpful and that you are able to get the maximum performance from your system. Neil Erbe Tampa, Fl WD1002S-WX2 Hard Drive Controller The following information on the Western Digital Controller is for the WD1002S-WX2 taken from the Western Digital Installation Guide. If you need help doing a low-level format on the drive, please leave a message in the Hard Drive Conference, Sparta PCBoard (201) 729-7056. The BIOS ROM is used to define individual disk drive parameters. Currently there are two varieties of BIOS ROMs available. The standard BIOS ROM contains a selection of four sets of drive parameters that can be used with most existing disk drives. In addition to this same selection of parameters, another BIOS ROM, called Auto Config BIOS ROM, allows manual assignment and modification of these drive parameters; has the ability to load a drive defect list; and lets the user logically format one disk drive as two virtual drives. Both versions of the BIOS ROM contain four drive configuration tables or BIOS tables as listed below: BIOS Drive Tables contained within the following BIOS ROMS Standard - WD62-000042-013 Auto Config - WD62-000043-010 Table 0 Specifications Drive Types Drive Capacity 20MB Microscience HH725/HH325 Cylinders 612 Tandon TM262/362 Heads 4 RWC 613(none) WPC 613(none) Step Rate Option 5 Table 1 Drive Capacity 10MB Miniscribe 3012/3212 Cylinders 612 Heads 4 RWC 128 WPC 128 Step Rate Option 5 Table 2 Drive Capacity 20MB CDC 9415-525AT/9415-528 Cylinders 612 Miniscribe 3425 Heads 4 Mivil M125/M225/M325 RWC 613(none) Seagate ST225 WPC 128 Step Rate Option 5 Table 3 Drive Capacity 10MB Fujitsu m2233 Cylinders 306 LaPine 3065/3512/3522 Heads 4 Microscience HH612/HH312 RWC 306(none) Miniscribe 2012 WPC 0 (all) Rodime 252/352 Step Rate Option 5 Seagate ST412 SW1 Jumper Positions 1 - 4 BIOS Table Drive 1 Drive 0 SW 1-1 SW 1-2 SW 1-3 SW 1-4 0 Close Close Close Close 1 Open Close Open Close 2 Close Open Close Open 3* Open Open Open Open *Shipping Configuration SW1 Jumper Positions 5 - 8 SW 1-8 Open Reserved for BIOS ROM SW 1-7 Open Reserved for BIOS ROM SW 1-6 Open Reserved for BIOS ROM SW 1-5 Open Reserved for BIOS ROM The following jumpers cover the W1 - W7 jumper positions Jumper Pin Connects Status W1 2-1 Normal* 2-3 Factory Test Only W2 2-1 Normal* 2-3 Factory Test Only W3 Closed BIOS ROM Enabled* Open BIOS ROM Disabled W4 2-3 Device Address 320H* 2-1 Device Address 324H W5 2-1 BIOS ROM Size 32K or 64K** 2-3 BIOS ROM Size 16K W6 2-3 Reduced Write Current (8 heads)* 2-1 Head Select 3 (16 heads) W7 2-1 INTRQ to INTRQ 5 on host connector** 2-3 INTRQ to INTRQ 2 on host connector * - As Shipped - Jumper is installed ** - As Shipped - Jumper is installed, Pins 1 and 2 are joined via an etch on the PCB. To change, the etch must be carefully cut and a jumper installed. Step Rates The WD1015 Control Processor uses the CCB Option Byte to establish the actuator step rate. This step rate is defaulted to either 70 or 75 microseconds on the installed version of the Control Processor. It can be modified by the Auto-Config BIOS ROM. The control processor is the chip located at U11 on the circuit board. An older version of the control processor, P/N WD1015-14, supports a maximum of 8 heads and is completely suitable for the lower capacity ST506 type disk drives. The default step rate is 70 microseconds. Today's control processor, the WD1015-24, supports up to 16 heads. It includes controller support to the DMA and Syquest removable drives. Other differences include: it no longer performs the unnecessary controller self-test after power-on or soft resets; the processor allows faster step rates; and the default step rate is 75 microseconds. The Auto-Config BIOS ROM can be used to change the step rate of either the WD1015-14 or -24 control processors. Table 5 lists the available step rates for both the WD1015-14 and the WD1015-24. Overall system performance will be enhanced by selecting the fastest possible step rate supported by the attached drive. Table 5 WD1015-14 Step Rates DEC BIN Step Rate Comments 0 000 3 ms 1 001 3 ms 2 010 3 ms 3 011 3 ms 4 100 200 us 5* 101 70 us Standard Buffered Seek Rate 6 110 3 ms 7 111 3 ms WD1015-24 Step Rates 0 000 3 ms 1 001 45 us 2 010 60 us 3 011 18 us 4 100 210 us 5* 101 75 us Standard Buffered Seek Rate 6 110 30 us 7 111 18 us * Default value in WD BIOS ROMS Sparta PCBoard Hard Drive Conference (201) 729-5377 or (201) 729-7056 Auto-config Formatting Procedures Western Digital WD 1002S-WX2 The following information is taken directly from the Western Digital Installation Guide for the WD 1002S-WX2 HD controller. For clarity I have inserted my own notes on some portions of the procedures that WD has lightly touched. Step Instructions 1. Correctly install or remove jumper on SW1-5. This is the uppermost jumper on SW1. Note: This jumper tells the BIOS to read the jumpers 1-4 on SW1 for the corresponding table to use or to accept keyboard input for the various parameters. 2. At the A Prompt, insert the PC-DOS Supplemental Diskette; load and run the PC-DOS debug utility by typing DEBUG. A>DEBUG c/r 3. At the debug prompt, initiate the WD format program by typing the following command line. The debug prompt is the hyphen "-". -g=c800:5 c/r 4. The WD format program will display the following message: WX2 Format Revision T.8 (c) Copyright Western digital Corp. 1985 Key in drive no and interleave as follows: d ii where d = relative no (0-1) ii = interleave factor (1-16) Enter d and ii separated by a space and followed with a Return Example: 0 03 c/r NOTE: Drive C: = 0, Drive D: = 1. An interleave factor of 3 is standard. If formatting two drives, this option must be run twice; once with d=0 and again with d=1. 5. The following message will be displayed: Key in disk characteristics as follows: ccc h rrr ppp ee oo where ccc = total number of cylinders (1-4 digits) h = number of heads (1-2 digits) rrr = starting reduced write cylinder (1-4 digits) ppp = write precomp cylinder (1-4 digits) ee = max correctable error burst (1-2 digits) oo = CCB option byte (1 hex digit) Enter each value separated by a space and follow entry with a return Example: 306 4 128 128 11 05 c/r 6. CPU Response (did you know cpu's respond?) Are you virtually configuring the drive - Answer Y/N Enter a "Y" and c/r for yes or "N" and c/r for no. Sysop note: All this is asking is "Do you want to split the drive into more than one volume"? 7. If Yes, the following message is displayed. Key in virtual drive size list as vvvv where vvvv = virtual drive size (1-4 digits) Enter two cylinder numbers, followed by a space and c/r Note: The sum of these two numbers cannot exceed the maximum number of available cylinders on your hard disk. Example: 153 153 c/r If No, continue to next step 8. The following message will be displayed. Press "y" to begin formatting drive d with interleave ii. Note: d = drive number and ii = interleave factor. Type "Y" followed by a c/r 9. System Responses: If any key other than "Y" is typed, the program displays the following message and returns to DOS. CPU response: Nothing done exit A> If an error occurs while formatting, the program will immediately terminate, display the following error message, and return to DOS. XX is the hexidecimal S-WX2 BIOS completion code. CPU response: Error----completion code XX A> If "Y" is typed, formatting is initiated. If there are no resulting errors, the program displays the following message. CPU response: Do you want to format bad tracks - answer Y/N Respond with appropriate Y or N followed by a c/r The user is prompted to enter, via the keyboard, a bad track list. This list should be provided by the drive manufacturer. However, due to DOS limitations, this procedure is not remommended. Sysop note: Let the sucker format the bad tracks and then use Norton's DT immediately after partitioning and high level format is performed to pick up any bad track information and mark them appropriately in the FAT. Because of the logical addressing used by DOS, marking an entire track bad will result in more than one logical address being marked bad. As DOS can only accept a limited number of defects, a drive with excessive defects may cause the format program to termnate with an error. The displayed error is typically "TRACK 00 BAD - DRIVE UNUSABLE". As a recommended alternative, execution of the DOS utility program FORMAT should correctly locate and deallocate all media defects. 10. If Yes, the following message is displayed. Key in bad track list as follows: ccc h ...(repeat) where ccc = bad track cylinder number (1-4 digits) h = bad track head number (1-2 digits) Type in the cylinder and head numbers for the bad tracks, separate them with spaces, and follow with a c/r Example: 160 1 161 1 304 3 223 4 223 2 c/r The bad track message will be displayed again. To terminate bad gtrack entry, type "N" followed by a c/r 11. The following message is displayed. Format successful - Returning to system If a second drive is to be formatted, repeat steps 4 through 13 with d = 1, otherwise continue. RUNNING THE FDISK UTILITY The FDISK utility partitions the drive for DOS. Please refer to the PC-DOS operating manual for detailed instructions regarding this utility. 12. Load and run the FDISK utility to set up the disk partitions. 13. CPU Response: IBM Personal Computer Fixed disk Setup Program Version 2.00 Copyright IBM Corp. 1983 FDISK Options Choose one of the following: 1. Create DOS Partition 2. Change Active Partition 3. Delete DOS Partition 4. Display Partition Data [5. Select Next Fixed Disk Drive] Enter Choice: Note: When two disk drives are installed, the system will automatically add a fifth choice on the menu: "5. Select Next Fixed Disk Drive". The first drive is partitioned using choice number 1. Then, the second drive is partitioned starting with choice number 5. All subsequent steps are the same for both drives. Select "Create DOS Partition" and enter a 1 followed by a c/r. 14. The following message will be displayed: Create Dos Partition Do you wish to use the entire fixed disk for DOS (Y/N)...........? Type a Y followed by a c/r 15. CPU response: System will now reboot Insert DOS diskette in Drive A: Press any key when ready.. RUNNING THE FORMAT UTILITY 16. Load and run the PC-DOS utility program FORMAT to write the DOS structure and syustem files to the disk. At the A prompt, type FORMAT C: /S/V followed by a c/r 17. The CPU will respond with: Press any key to begin formatting C: 18. The System will respond with: Formatting....Format Complete system transferred Volume Label(11 Characters, ENTER for none)? 19. Either enter the optional volume name and press c/r or just press c/r 20. When the FORMAT program is finished, the hard disk is ready to be booted from. It will contain the file COMMAND.COM and the two system files which are hidden. Note: This is known as the "high level" format process. If a second drive, or Drive D:, is to be formatted, repeat steps 12 through 19. When running FDISK on the second drive, enter choice [5] first, then continue as before. 21, To verify that the hard disk will now boot, open the door of the floppy drive and do a warm boot by simultaneously pressing CTRL, ALT, and DEL (We call this the three finger salute). The system BIOS first examines Drive A for a system diskette. If it doesn't find one, then it will try to boot from the C drive, the hard disk. If the hard disk boot is successful, the system will assert the date, time, and C> prompts in order. Other files may now be copied to the hard disk. Sysop Note: I am going to throw some technical mumbo jumbo in here just to make you feel comfortable with the info you are typing into the questions asked by WD's program. The HD controller provides a system interface to the hardware and onboard BIOS through direct and indirect i/o. Direct access is accomplished by reading and writing to four I/O ports. Indirect access is achieved by executing pre-written I/O subroutines contained in the BIOS on the controller. Commands are issued by the CPU to the controller over the host buss using a pre-defined protocol (known as ST506/412). The CPU issues a command sequence by selecting the controller. The controller accepts the selection, and requests the appropriate command bytes. Upon command completion, the controller issues completion status to indicate whether the command was successfully completed or terminated because of an error. Direct access operations are controlled through four I/O ports (assigned default addresses 320H, 321H, 322H, and 323H). Each port is assigned one Read register and one Write register as follows: Registers Port Read Write 320H Data IN Data OUT 321H Status Reset (function) 322H Configuration Select (function) 323H N/A Mask The CPU specified the operation or command to be executed by the controller by sending a 6 or 10 byte Command Descriptor Block (CDB). The CCB we were asked for earlier in the WD formatter routine is called the Command Control Byte and is the last byte in the CDB. It specifies the error recovery procedure during the command execution. The ECC is comparable to CRC on a floppy drive. It is known as Error Correction Code and is set on or off by one of the bits in Byte 5 of the CDB. My fingers are tired at this point and I am not going to get into a further detailed discussion of each bit and its values in the CDB. If you wish to obtain further information, give us a call at Sparta PCBoard, join the HD conference, and fire away at us. We may not have the answer, but we can usually get it. Richard Driggers SysOp - Sparta PCBoard -eof-