1ide.txt -- Information regarding the Enhanced IDE drive in Linux 2.2/2.3/2.4 2=============================================================================== 3 4 +-----------------------------------------------------------------+ 5 | The hdparm utility for controlling various IDE features is | 6 | packaged separately. Look for it on popular linux FTP sites. | 7 +-----------------------------------------------------------------+ 8 9See description later on below for handling BIG IDE drives with >1024 cyls. 10 11Major features of the 2.1/2.2 IDE driver ("NEW!" marks changes since 2.0.xx): 12 13NEW! - support for IDE ATAPI *floppy* drives 14 - support for IDE ATAPI *tape* drives, courtesy of Gadi Oxman 15 (re-run MAKEDEV.ide to create the tape device entries in /dev/) 16 - support for up to *four* IDE interfaces on one or more IRQs 17 - support for any mix of up to *eight* IDE drives 18 - support for reading IDE ATAPI cdrom drives (NEC,MITSUMI,VERTOS,SONY) 19 - support for audio functions 20 - auto-detection of interfaces, drives, IRQs, and disk geometries 21 - "single" drives should be jumpered as "master", not "slave" 22 (both are now probed for) 23 - support for BIOSs which report "more than 16 heads" on disk drives 24 - uses LBA (slightly faster) on disk drives which support it 25 - support for lots of fancy (E)IDE drive functions with hdparm utility 26 - optional (compile time) support for 32-bit VLB data transfers 27 - support for IDE multiple (block) mode (same as hd.c) 28 - support for interrupt unmasking during I/O (better than hd.c) 29 - improved handshaking and error detection/recovery 30 - can co-exist with hd.c controlling the first interface 31 - run-time selectable 32bit interface support (using hdparm-2.3) 32 - support for reliable operation of buggy RZ1000 interfaces 33 - PCI support is automatic when rz1000 support is configured 34 - support for reliable operation of buggy CMD-640 interfaces 35 - PCI support is automatic when cmd640 support is configured 36 - for VLB, use kernel command line option: ide0=cmd640_vlb 37 - this support also enables the secondary i/f when needed 38 - interface PIO timing & prefetch parameter support 39 - experimental support for UMC 8672 interfaces 40 - support for secondary interface on the FGI/Holtek HT-6560B VLB i/f 41 - use kernel command line option: ide0=ht6560b 42 - experimental support for various IDE chipsets 43 - use appropriate kernel command line option from list below 44 - support for drives with a stuck WRERR_STAT bit 45 - support for removable devices, including door lock/unlock 46 - transparent support for DiskManager 6.0x and "Dynamic Disk Overlay" 47 - works with Linux fdisk, LILO, loadlin, bootln, etc.. 48 - mostly transparent support for EZ-Drive disk translation software 49 - to use LILO with EZ, install LILO on the linux partition 50 rather than on the master boot record, and then mark the 51 linux partition as "bootable" or "active" using fdisk. 52 (courtesy of Juha Laiho <jlaiho@ichaos.nullnet.fi>). 53 - auto-detect of disk translations by examining partition table 54 - ide-cd.c now compiles separate from ide.c 55 - ide-cd.c now supports door locking and auto-loading. 56 - Also preliminary support for multisession 57 and direct reads of audio data. 58 - experimental support for Promise DC4030VL caching interface card 59 - email thanks/problems to: peterd@pnd-pc.demon.co.uk 60 - the hdparm-3.1 package can be used to set PIO modes for some chipsets. 61NEW! - support for setting PIO modes with the OPTi 82C621, courtesy of Jaromir Koutek. 62NEW! - support for loadable modules 63NEW! - optional SCSI host adapter emulation for ATAPI devices 64NEW! - generic PCI Bus-Master DMA support 65NEW! - works with most Pentium PCI systems, chipsets, add-on cards 66NEW! - works with regular DMA as well as Ultra DMA 67NEW! - automatically probes for all PCI IDE interfaces 68NEW! - generic support for using BIOS-configured Ultra-DMA (UDMA) transfers 69 70 71*** IMPORTANT NOTICES: BUGGY IDE CHIPSETS CAN CORRUPT DATA!! 72*** ================= 73*** PCI versions of the CMD640 and RZ1000 interfaces are now detected 74*** automatically at startup when PCI BIOS support is configured. 75*** 76*** Linux disables the "prefetch" ("readahead") mode of the RZ1000 77*** to prevent data corruption possible due to hardware design flaws. 78*** 79*** For the CMD640, linux disables "IRQ unmasking" (hdparm -u1) on any 80*** drive for which the "prefetch" mode of the CMD640 is turned on. 81*** If "prefetch" is disabled (hdparm -p8), then "IRQ unmasking" can be 82*** used again. 83*** 84*** For the CMD640, linux disables "32bit I/O" (hdparm -c1) on any drive 85*** for which the "prefetch" mode of the CMD640 is turned off. 86*** If "prefetch" is enabled (hdparm -p9), then "32bit I/O" can be 87*** used again. 88*** 89*** The CMD640 is also used on some Vesa Local Bus (VLB) cards, and is *NOT* 90*** automatically detected by Linux. For safe, reliable operation with such 91*** interfaces, one *MUST* use the "ide0=cmd640_vlb" kernel option. 92*** 93*** Use of the "serialize" option is no longer necessary. 94 95This is the multiple IDE interface driver, as evolved from hd.c. 96It supports up to six IDE interfaces, on one or more IRQs (usually 14 & 15). 97There can be up to two drives per interface, as per the ATA-2 spec. 98 99Primary: ide0, port 0x1f0; major=3; hda is minor=0; hdb is minor=64 100Secondary: ide1, port 0x170; major=22; hdc is minor=0; hdd is minor=64 101Tertiary: ide2, port 0x1e8; major=33; hde is minor=0; hdf is minor=64 102Quaternary: ide3, port 0x168; major=34; hdg is minor=0; hdh is minor=64 103fifth.. ide4, usually PCI, probed 104sixth.. ide5, usually PCI, probed 105 106To access devices on interfaces > ide0, device entries must first be 107created in /dev for them. To create such entries, simply run the included 108shell script: /usr/src/linux/scripts/MAKEDEV.ide 109 110Apparently many older releases of Slackware had incorrect entries 111in /dev for hdc* and hdd* -- this can also be corrected by running MAKEDEV.ide 112 113ide.c automatically probes for most IDE interfaces (including all PCI ones), 114for the drives/geometries attached to those interfaces, and for the 115IRQ numbers being used by the interfaces (normally 14, 15 for ide0/ide1). 116 117For special cases, interfaces may be specified using kernel "command line" 118options. For example, 119 120 ide3=0x168,0x36e,10 /* ioports 0x168-0x16f,0x36e, irq 10 */ 121 122Normally the irq number need not be specified, as ide.c will probe for it: 123 124 ide3=0x168,0x36e /* ioports 0x168-0x16f,0x36e */ 125 126The standard port, and irq values are these: 127 128 ide0=0x1f0,0x3f6,14 129 ide1=0x170,0x376,15 130 ide2=0x1e8,0x3ee,11 131 ide3=0x168,0x36e,10 132 133Note that the first parameter reserves 8 contiguous ioports, whereas the 134second value denotes a single ioport. If in doubt, do a 'cat /proc/ioports'. 135 136In all probability the device uses these ports and IRQs if it is attached 137to the appropriate ide channel. Pass the parameter for the correct ide 138channel to the kernel, as explained above. 139 140Any number of interfaces may share a single IRQ if necessary, at a slight 141performance penalty, whether on separate cards or a single VLB card. 142The IDE driver automatically detects and handles this. However, this may 143or may not be harmful to your hardware.. two or more cards driving the same IRQ 144can potentially burn each other's bus driver, though in practice this 145seldom occurs. Be careful, and if in doubt, don't do it! 146 147Drives are normally found by auto-probing and/or examining the CMOS/BIOS data. 148For really weird situations, the apparent (fdisk) geometry can also be specified 149on the kernel "command line" using LILO. The format of such lines is: 150 151 hdx=cyls,heads,sects,wpcom,irq 152or hdx=cdrom 153 154where hdx can be any of hda through hdh, Three values are required 155(cyls,heads,sects). For example: 156 157 hdc=1050,32,64 hdd=cdrom 158 159either {hda,hdb} or {hdc,hdd}. The results of successful auto-probing may 160override the physical geometry/irq specified, though the "original" geometry 161may be retained as the "logical" geometry for partitioning purposes (fdisk). 162 163If the auto-probing during boot time confuses a drive (ie. the drive works 164with hd.c but not with ide.c), then an command line option may be specified 165for each drive for which you'd like the drive to skip the hardware 166probe/identification sequence. For example: 167 168 hdb=noprobe 169or 170 hdc=768,16,32 171 hdc=noprobe 172 173Note that when only one IDE device is attached to an interface, 174it should be jumpered as "single" or "master", *not* "slave". 175Many folks have had "trouble" with cdroms because of this requirement, 176so ide.c now probes for both units, though success is more likely 177when the drive is jumpered correctly. 178 179Courtesy of Scott Snyder and others, the driver supports ATAPI cdrom drives 180such as the NEC-260 and the new MITSUMI triple/quad speed drives. 181Such drives will be identified at boot time, just like a hard disk. 182 183If for some reason your cdrom drive is *not* found at boot time, you can force 184the probe to look harder by supplying a kernel command line parameter 185via LILO, such as: 186 187 hdc=cdrom /* hdc = "master" on second interface */ 188or 189 hdd=cdrom /* hdd = "slave" on second interface */ 190 191For example, a GW2000 system might have a hard drive on the primary 192interface (/dev/hda) and an IDE cdrom drive on the secondary interface 193(/dev/hdc). To mount a CD in the cdrom drive, one would use something like: 194 195 ln -sf /dev/hdc /dev/cdrom 196 mkdir /cd 197 mount /dev/cdrom /cd -t iso9660 -o ro 198 199If, after doing all of the above, mount doesn't work and you see 200errors from the driver (with dmesg) complaining about `status=0xff', 201this means that the hardware is not responding to the driver's attempts 202to read it. One of the following is probably the problem: 203 204 - Your hardware is broken. 205 206 - You are using the wrong address for the device, or you have the 207 drive jumpered wrong. Review the configuration instructions above. 208 209 - Your IDE controller requires some nonstandard initialization sequence 210 before it will work properly. If this is the case, there will often 211 be a separate MS-DOS driver just for the controller. IDE interfaces 212 on sound cards usually fall into this category. Such configurations 213 can often be made to work by first booting MS-DOS, loading the 214 appropriate drivers, and then warm-booting linux (without powering 215 off). This can be automated using loadlin in the MS-DOS autoexec. 216 217If you always get timeout errors, interrupts from the drive are probably 218not making it to the host. Check how you have the hardware jumpered 219and make sure it matches what the driver expects (see the configuration 220instructions above). If you have a PCI system, also check the BIOS 221setup; I've had one report of a system which was shipped with IRQ 15 222disabled by the BIOS. 223 224The kernel is able to execute binaries directly off of the cdrom, 225provided it is mounted with the default block size of 1024 (as above). 226 227Please pass on any feedback on any of this stuff to the maintainer, 228whose address can be found in linux/MAINTAINERS. 229 230Note that if BOTH hd.c and ide.c are configured into the kernel, 231hd.c will normally be allowed to control the primary IDE interface. 232This is useful for older hardware that may be incompatible with ide.c, 233and still allows newer hardware to run on the 2nd/3rd/4th IDE ports 234under control of ide.c. To have ide.c also "take over" the primary 235IDE port in this situation, use the "command line" parameter: ide0=0x1f0 236 237The IDE driver is partly modularized. The high level disk/cdrom/tape/floppy 238drivers can always be compiled as loadable modules, the chipset drivers 239can only be compiled into the kernel, and the core code (ide.c) can be 240compiled as a loadable module provided no chipset support and no special 241partition table translations are needed. 242 243When using ide.c/ide-tape.c as modules in combination with kerneld, add: 244 245 alias block-major-3 ide-probe 246 alias char-major-37 ide-tape 247 248respectively to /etc/modules.conf. 249 250When ide.c is used as a module, you can pass command line parameters to the 251driver using the "options=" keyword to insmod, while replacing any ',' with 252';'. For example: 253 254 insmod ide.o options="ide0=serialize ide2=0x1e8;0x3ee;11" 255 256 257================================================================================ 258 259Summary of ide driver parameters for kernel "command line": 260---------------------------------------------------------- 261 "hdx=" is recognized for all "x" from "a" to "h", such as "hdc". 262 "idex=" is recognized for all "x" from "0" to "3", such as "ide1". 263 264 "hdx=noprobe" : drive may be present, but do not probe for it 265 "hdx=none" : drive is NOT present, ignore cmos and do not probe 266 "hdx=nowerr" : ignore the WRERR_STAT bit on this drive 267 "hdx=cdrom" : drive is present, and is a cdrom drive 268 "hdx=cyl,head,sect" : disk drive is present, with specified geometry 269 "hdx=autotune" : driver will attempt to tune interface speed 270 to the fastest PIO mode supported, 271 if possible for this drive only. 272 Not fully supported by all chipset types, 273 and quite likely to cause trouble with 274 older/odd IDE drives. 275 "hdx=slow" : insert a huge pause after each access to the data 276 port. Should be used only as a last resort. 277 "hdx=swapdata" : when the drive is a disk, byte swap all data 278 279 "hdxlun=xx" : set the drive last logical unit 280 281 "idebus=xx" : inform IDE driver of VESA/PCI bus speed in MHz, 282 where "xx" is between 20 and 66 inclusive, 283 used when tuning chipset PIO modes. 284 For PCI bus, 25 is correct for a P75 system, 285 30 is correct for P90,P120,P180 systems, 286 and 33 is used for P100,P133,P166 systems. 287 If in doubt, use idebus=33 for PCI. 288 As for VLB, it is safest to not specify it. 289 Bigger values are safer than smaller ones. 290 291 "idex=noprobe" : do not attempt to access/use this interface 292 "idex=base" : probe for an interface at the addr specified, 293 where "base" is usually 0x1f0 or 0x170 294 and "ctl" is assumed to be "base"+0x206 295 "idex=base,ctl" : specify both base and ctl 296 "idex=base,ctl,irq" : specify base, ctl, and irq number 297 "idex=autotune" : driver will attempt to tune interface speed 298 to the fastest PIO mode supported, 299 for all drives on this interface. 300 Not fully supported by all chipset types, 301 and quite likely to cause trouble with 302 older/odd IDE drives. 303 "idex=noautotune" : driver will NOT attempt to tune interface speed 304 This is the default for most chipsets, 305 except the cmd640. 306 "idex=serialize" : do not overlap operations on idex and ide(x^1) 307 "idex=reset" : reset interface after probe 308 "idex=dma" : automatically configure/use DMA if possible. 309 "idex=nohighio" : don't use i/o to high memory addresses on this 310 interface. i/o to memory locations higher 311 than ~860MiB will be bounced. 312 313 The following are valid ONLY on ide0, 314 and the defaults for the base,ctl ports must not be altered. 315 316 "ide0=dtc2278" : probe/support DTC2278 interface 317 "ide0=ht6560b" : probe/support HT6560B interface 318 "ide0=cmd640_vlb" : *REQUIRED* for VLB cards with the CMD640 chip 319 (not for PCI -- automatically detected) 320 "ide0=qd65xx" : probe/support qd65xx interface 321 "ide0=ali14xx" : probe/support ali14xx chipsets (ALI M1439/M1445) 322 "ide0=umc8672" : probe/support umc8672 chipsets 323 324There may be more options than shown -- use the source, Luke! 325 326Everything else is rejected with a "BAD OPTION" message. 327 328================================================================================ 329 330Some Terminology 331---------------- 332IDE = Integrated Drive Electronics, meaning that each drive has a built-in 333controller, which is why an "IDE interface card" is not a "controller card". 334 335IDE drives are designed to attach almost directly to the ISA bus of an AT-style 336computer. The typical IDE interface card merely provides I/O port address 337decoding and tri-state buffers, although several newer localbus cards go much 338beyond the basics. When purchasing a localbus IDE interface, avoid cards with 339an onboard BIOS and those which require special drivers. Instead, look for a 340card which uses hardware switches/jumpers to select the interface timing speed, 341to allow much faster data transfers than the original 8MHz ISA bus allows. 342 343ATA = AT (the old IBM 286 computer) Attachment Interface, a draft American 344National Standard for connecting hard drives to PCs. This is the official 345name for "IDE". 346 347The latest standards define some enhancements, known as the ATA-2 spec, 348which grew out of vendor-specific "Enhanced IDE" (EIDE) implementations. 349 350ATAPI = ATA Packet Interface, a new protocol for controlling the drives, 351similar to SCSI protocols, created at the same time as the ATA2 standard. 352ATAPI is currently used for controlling CDROM and TAPE devices, and will 353likely also soon be used for Floppy drives, removable R/W cartridges, 354and for high capacity hard disk drives. 355 356How To Use *Big* ATA/IDE drives with Linux 357------------------------------------------ 358The ATA Interface spec for IDE disk drives allows a total of 28 bits 359(8 bits for sector, 16 bits for cylinder, and 4 bits for head) for addressing 360individual disk sectors of 512 bytes each (in "Linear Block Address" (LBA) 361mode, there is still only a total of 28 bits available in the hardware). 362This "limits" the capacity of an IDE drive to no more than 128GB (Giga-bytes). 363All current day IDE drives are somewhat smaller than this upper limit, and 364within a few years, ATAPI disk drives will raise the limit considerably. 365 366All IDE disk drives "suffer" from a "16-heads" limitation: the hardware has 367only a four bit field for head selection, restricting the number of "physical" 368heads to 16 or less. Since the BIOS usually has a 63 sectors/track limit, 369this means that all IDE drivers larger than 504MB (528Meg) must use a "physical" 370geometry with more than 1024 cylinders. 371 372 (1024cyls * 16heads * 63sects * 512bytes/sector) / (1024 * 1024) == 504MB 373 374(Some BIOSs (and controllers with onboard BIOS) pretend to allow "32" or "64" 375 heads per drive (discussed below), but can only do so by playing games with 376 the real (hidden) geometry, which is always limited to 16 or fewer heads). 377 378This presents two problems to most systems: 379 380 1. The INT13 interface to the BIOS only allows 10-bits for cylinder 381 addresses, giving a limit of 1024cyls for programs which use it. 382 383 2. The physical geometry fields of the disk partition table only 384 allow 10-bits for cylinder addresses, giving a similar limit of 1024 385 cyls for operating systems that do not use the "sector count" fields 386 instead of the physical Cyl/Head/Sect (CHS) geometry fields. 387 388Neither of these limitations affects Linux itself, as it (1) does not use the 389BIOS for disk access, and it (2) is clever enough to use the "sector count" 390fields of the partition table instead of the physical CHS geometry fields. 391 392 a) Most folks use LILO to load linux. LILO uses the INT13 interface 393 to the BIOS to load the kernel at boot time. Therefore, LILO can only 394 load linux if the files it needs (usually just the kernel images) are 395 located below the magic 1024 cylinder "boundary" (more on this later). 396 397 b) Many folks also like to have bootable DOS partitions on their 398 drive(s). DOS also uses the INT13 interface to the BIOS, not only 399 for booting, but also for operation after booting. Therefore, DOS 400 can normally only access partitions which are contained entirely below 401 the magic 1024 cylinder "boundary". 402 403There are at least seven commonly used schemes for kludging DOS to work 404around this "limitation". In the long term, the problem is being solved 405by introduction of an alternative BIOS interface that does not have the 406same limitations as the INT13 interface. New versions of DOS are expected 407to detect and use this interface in systems whose BIOS provides it. 408 409But in the present day, alternative solutions are necessary. 410 411The most popular solution in newer systems is to have the BIOS shift bits 412between the cylinder and head number fields. This is activated by entering 413a translated logical geometry into the BIOS/CMOS setup for the drive. 414Thus, if the drive has a geometry of 2100/16/63 (CHS), then the BIOS could 415present a "logical" geometry of 525/64/63 by "shifting" two bits from the 416cylinder number into the head number field for purposes of the partition table, 417CMOS setup, and INT13 interfaces. Linux kernels 1.1.39 and higher detect and 418"handle" this translation automatically, making this a rather painless solution 419for the 1024 cyls problem. If for some reason Linux gets confused (unlikely), 420then use the kernel command line parameters to pass the *logical* geometry, 421as in: hda=525,64,63 422 423If the BIOS does not support this form of drive translation, then several 424options remain, listed below in order of popularity: 425 426 - use a partition below the 1024 cyl boundary to hold the linux 427 boot files (kernel images and /boot directory), and place the rest 428 of linux anywhere else on the drive. These files can reside in a DOS 429 partition, or in a tailor-made linux boot partition. 430 - use DiskManager software from OnTrack, supplied free with 431 many new hard drive purchases. 432 - use EZ-Drive software (similar to DiskManager). Note though, 433 that LILO must *not* use the MBR when EZ-Drive is present. 434 Instead, install LILO on the first sector of your linux partition, 435 and mark it as "active" or "bootable" with fdisk. 436 - boot from a floppy disk instead of the hard drive (takes 10 seconds). 437 438If you cannot use drive translation, *and* your BIOS also restricts you to 439entering no more than 1024 cylinders in the geometry field in the CMOS setup, 440then just set it to 1024. As of v3.5 of this driver, Linux automatically 441determines the *real* number of cylinders for fdisk to use, allowing easy 442access to the full disk capacity without having to fiddle around. 443 444Regardless of what you do, all DOS partitions *must* be contained entirely 445within the first 1024 logical cylinders. For a 1Gig WD disk drive, here's 446a good "half and half" partitioning scheme to start with: 447 448 geometry = 2100/16/63 449 /dev/hda1 from cyl 1 to 992 dos 450 /dev/hda2 from cyl 993 to 1023 swap 451 /dev/hda3 from cyl 1024 to 2100 linux 452 453To ensure that LILO can boot linux, the boot files (kernel and /boot/*) 454must reside within the first 1024 cylinders of the drive. If your linux 455root partition is *not* completely within the first 1024 cyls (quite common), 456then you can use LILO to boot linux from files on your DOS partition 457by doing the following after installing Slackware (or whatever): 458 459 0. Boot from the "boot floppy" created during the installation 460 1. Mount your DOS partition as /dos (and stick it in /etc/fstab) 461 2. Move /boot to /dos/boot with: cp -a /boot /dos ; rm -r /boot 462 3. Create a symlink for LILO to use with: ln -s /dos/boot /boot 463 4. Move your kernel (/vmlinuz) to /boot/vmlinuz: mv /vmlinuz /boot 464 5. Edit /etc/lilo.conf to change /vmlinuz to /boot/vmlinuz 465 6. Re-run LILO with: lilo 466 467 A danger with this approach is that whenever an MS-DOS "defragmentation" 468 program is run (like Norton "speeddisk"), it may move the Linux boot 469 files around, confusing LILO and making the (Linux) system unbootable. 470 Be sure to keep a kernel "boot floppy" at hand for such circumstances. 471 A possible workaround is to mark the Linux files as S+H+R (System, 472 Hidden, Readonly), to prevent most defragmentation programs from 473 moving the files around. 474 475If you "don't do DOS", then partition as you please, but remember to create 476a small partition to hold the /boot directory (and vmlinuz) as described above 477such that they stay within the first 1024 cylinders. 478 479Note that when creating partitions that span beyond cylinder 1024, 480Linux fdisk will complain about "Partition X has different physical/logical 481endings" and emit messages such as "This is larger than 1024, and may cause 482problems with some software". Ignore this for linux partitions. The "some 483software" refers to DOS, the BIOS, and LILO, as described previously. 484 485Western Digital ships a "DiskManager 6.03" diskette with all of their big 486hard drives. Use BIOS translation instead of this if possible, as it is a 487more generally compatible method of achieving the same results (DOS access 488to the entire disk). However, if you must use DiskManager, it now works 489with Linux 1.3.x in most cases. Let me know if you still have trouble. 490 491My recommendations to anyone who asks about NEW systems are: 492 493 - buy a motherboard that uses the Intel Triton chipset -- very common. 494 - use IDE for the first two drives, placing them on separate interfaces. 495 - very fast 7200rpm drives are now available 496 (though many problems have been reported with Seagate ones). 497 - place the IDE cdrom drive as slave on either interface. 498 - if additional disks are to be connected, consider your needs: 499 - fileserver? Buy a SC200 SCSI adaptor for the next few drives. 500 - personal system? Use IDE for the next two drives. 501 - still not enough? Keep adding SC200 SCSI cards as needed. 502 503Most manufacturers make both IDE and SCSI versions of each of their drives. 504The IDE ones are usually as fast and cheaper, due to lower command overhead 505and the higher data transfer speed of UDMA2. But fast/ultrawide/superlative 506SCSI is still king of the heap, especially for servers, if you've got the bucks. 507 508mlord@pobox.com 509-- 510For current maintainers of this stuff, see the linux/MAINTAINERS file. 511