Home » Personal collection » Acorn ADFS disks » Electron_User_Group » EUG_35.ADF » F/+HARD1
F/+HARD1
This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.
Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.
| Tape/disk: | Home » Personal collection » Acorn ADFS disks » Electron_User_Group » EUG_35.ADF |
| Filename: | F/+HARD1 |
| Read OK: | ✔ |
| File size: | 1780 bytes |
| Load address: | 2B204556 |
| Exec address: | 44524148 |
Duplicates
There is 1 duplicate copy of this file in the archive:
- Personal collection » Acorn ADFS disks » Electron_User_Group » EUG_35.ADF » F/+HARD1
- Personal collection » Acorn hard disk » zipped_disks » elk03 » eug35/F/+HARD1
File contents
These are the notes which I have on adding a hard disc. I have the circuit diagram for the host adaptor. I will try to put it into a future EUG. The following notes were written some time ago and so prices and any sources named will be out of date. Winchester disk systems - background Unlike a floppy disk a Winchester disk drive is much faster (it spins at 3600rpm instead of 360rpm) and can store from ten to hundreds/thousands of times more data. In addition to being faster is also has more heads (from 2 to 16 heads), the data transfer rate from the disk to the controller is 5Mb/s. As a trade off a Winchester disk is permanently sealed in it's housing and cannot be removed, extra controller circuitry is also needed to interface it. Most Winchester drives are the same physical size as a 5.25" full height or half height floppy drive and come in numerous storage capacities ranging from 5Mb to around 140Mb (10Mb is most common and usually affordable). The drive will have three connectors, power, data and control. The SASI (Shugart Associates Standard Interface) ST406/506 applies to the data and control connectors, basically the control connector is a 34 way edge connector carrying similar control functions to those found on a standard floppy disk, and the data connector is a 20 way edge connector that carries the data to/from the head(s). The Winchester disk cannot be connected to a micro computer directly, instead an intelligent (microprocessor based) controller has to used. The Winchester controller is a vital part of the system, it is operated under software control of the host and performs all the read/write/seek/format operations on the Winchester - the host has only to send high level "commands" to the controller to be able to use the winchester. About controllers and all that... To the host, the Winchester just looks like a large number of sectors (or blocks), the host is not concerned with the track/cylinder/head/sector number, it simply uses a Disk Address (DA) which uniquely refers to each sector (the Disk Address ranges from zero to the maximum which is number of cylinders * number of heads * number of sectors per track - 1). The Disk Address is represented by a 24 bit number (3 hex bytes), so drive 0 head 0 track 0 is DA 000000, sector 1 is 000001 etc. to the end of the disk. This notation is very convenient as it allows media independence in the filing system, for example a floppy disk can be addressed in the same way, it just has less sectors so it has a correspondingly lower maximum DA. Again there is a SASI standard for controllers, originally it defined only the electrical interface signals, but a defacto standard emerged for the majority of high level commands, so in most applications controllers are interchangeable. Most controllers can support two winchester drives (connected by the 34 way and 20 way sockets) and provide a 50 way socket to the host. This socket provides a bi directional 8 bit parallel data port and a number of input and output hand shaking signals, these TTL level signals have to be interfaced to the host and software provided for data I/O. To be more precise the Disk Address is actually a 21 bit number which represents the sector number, and a 3 bit number which represents the device on the controller (or Logical Unit Number, the LUN has a range from 0-7). Most SASI controllers support more than one device, for example SASI controllers to support 2 Winchesters only, 2 winchesters + 2 floppies, or 1 Winchester and 1 tape streamer are common. Each connection port on a controller has a LUN related to it such that requests for I/O to a LUN are channeled to a particular port. Some controllers can be daisy chained on the SASI bus to make use of all 8 LUNs (the controller can be configured, by links or software, to map particular LUNs to particular devices). As an example, the DTC 520A controller board supports 2 Winchesters and 2 floppies, accesses are as follows: LUN = 0 First Winchester (Winchester port 0) LUN = 1 Second Winchester (Winchester port 1) LUN = 2 First floppy (Floppy port 0) LUN = 3 Second floppy (Floppy port 1) Usually a controller can support two Winchesters (all the ones I have met do), but some only allow this if the two devices are of the same type and capacity others allow the size/capacity of each drive to be specified to the controller - it's safer to use one Winchester or two of the same size (a friend nearly ruined a 20Mb Rodime when using it in conjunction with a 10Mb Rodime). There are two distinct types of formatting a controller can use on a Winchester: MFM (Modified Frequency Modulation) and RLL (Run Length Limiting - sometimes known as 2,7 RLL). Basically RLL is the newer technique which uses a type of data compression to get more data onto the disk (a bit like using double density on floppy disks) but requires a disk capable of supporting RLL (the transfer rate is increased to approximately 7.5Mb/s). Also the controller has to be able to support RLL (eg. Adaptec ACB4070). Most controllers on the second hand market support only MFM and most drives were intended for use with MFM. My advice is to stick with MFM unless you really need the extra space - also it's probably cheaper to use a bigger drive with MFM than to purchase a RLL controller. Controllers are not, unfortunately, interchangeable. That is a Winchester that has been formatted by one controller cannot be read or written to by a different make of controller. This is because the different controller manufacturers use slightly different methods of putting the data onto the disk, different numbers of sectors per track etc. Another compatibility "problem" with controllers is how they are informed about the size/shape of the Winchester attached. All controllers have a "default" drive configuration at power up (usually a Shugart 5Mb drive) which is not much use unless you happen to be using this type of drive... 3 ways around this problem are used:
00000000 54 68 65 73 65 20 61 72 65 20 74 68 65 20 6e 6f |These are the no| 00000010 74 65 73 20 77 68 69 63 68 20 49 20 68 61 76 65 |tes which I have| 00000020 20 6f 6e 20 61 64 64 69 6e 67 20 61 20 68 61 72 | on adding a har| 00000030 64 20 64 69 73 63 2e 0d 0d 49 20 68 61 76 65 20 |d disc...I have | 00000040 74 68 65 20 63 69 72 63 75 69 74 20 64 69 61 67 |the circuit diag| 00000050 72 61 6d 20 66 6f 72 20 74 68 65 20 68 6f 73 74 |ram for the host| 00000060 20 61 64 61 70 74 6f 72 2e 20 49 20 77 69 6c 6c | adaptor. I will| 00000070 20 74 72 79 20 74 6f 20 70 75 74 20 69 74 20 69 | try to put it i| 00000080 6e 74 6f 0d 61 20 66 75 74 75 72 65 20 45 55 47 |nto.a future EUG| 00000090 2e 0d 0d 54 68 65 20 66 6f 6c 6c 6f 77 69 6e 67 |...The following| 000000a0 20 6e 6f 74 65 73 20 77 65 72 65 20 77 72 69 74 | notes were writ| 000000b0 74 65 6e 20 73 6f 6d 65 20 74 69 6d 65 20 61 67 |ten some time ag| 000000c0 6f 20 61 6e 64 20 73 6f 20 70 72 69 63 65 73 20 |o and so prices | 000000d0 61 6e 64 20 61 6e 79 0d 73 6f 75 72 63 65 73 20 |and any.sources | 000000e0 6e 61 6d 65 64 20 77 69 6c 6c 20 62 65 20 6f 75 |named will be ou| 000000f0 74 20 6f 66 20 64 61 74 65 2e 0d 0d 57 69 6e 63 |t of date...Winc| 00000100 68 65 73 74 65 72 20 64 69 73 6b 20 73 79 73 74 |hester disk syst| 00000110 65 6d 73 20 2d 20 62 61 63 6b 67 72 6f 75 6e 64 |ems - background| 00000120 0d 0d 55 6e 6c 69 6b 65 20 61 20 66 6c 6f 70 70 |..Unlike a flopp| 00000130 79 20 64 69 73 6b 20 61 20 57 69 6e 63 68 65 73 |y disk a Winches| 00000140 74 65 72 20 64 69 73 6b 20 64 72 69 76 65 20 69 |ter disk drive i| 00000150 73 20 6d 75 63 68 20 66 61 73 74 65 72 20 28 69 |s much faster (i| 00000160 74 20 73 70 69 6e 73 20 61 74 0d 33 36 30 30 72 |t spins at.3600r| 00000170 70 6d 20 69 6e 73 74 65 61 64 20 6f 66 20 33 36 |pm instead of 36| 00000180 30 72 70 6d 29 20 61 6e 64 20 63 61 6e 20 73 74 |0rpm) and can st| 00000190 6f 72 65 20 66 72 6f 6d 20 74 65 6e 20 74 6f 20 |ore from ten to | 000001a0 68 75 6e 64 72 65 64 73 2f 74 68 6f 75 73 61 6e |hundreds/thousan| 000001b0 64 73 20 6f 66 0d 74 69 6d 65 73 20 6d 6f 72 65 |ds of.times more| 000001c0 20 64 61 74 61 2e 20 20 49 6e 20 61 64 64 69 74 | data. In addit| 000001d0 69 6f 6e 20 74 6f 20 62 65 69 6e 67 20 66 61 73 |ion to being fas| 000001e0 74 65 72 20 69 73 20 61 6c 73 6f 20 68 61 73 20 |ter is also has | 000001f0 6d 6f 72 65 20 68 65 61 64 73 20 28 66 72 6f 6d |more heads (from| 00000200 0d 32 20 74 6f 20 31 36 20 68 65 61 64 73 29 2c |.2 to 16 heads),| 00000210 20 74 68 65 20 64 61 74 61 20 74 72 61 6e 73 66 | the data transf| 00000220 65 72 20 72 61 74 65 20 66 72 6f 6d 20 74 68 65 |er rate from the| 00000230 20 64 69 73 6b 20 74 6f 20 74 68 65 20 63 6f 6e | disk to the con| 00000240 74 72 6f 6c 6c 65 72 20 69 73 0d 35 4d 62 2f 73 |troller is.5Mb/s| 00000250 2e 20 20 41 73 20 61 20 74 72 61 64 65 20 6f 66 |. As a trade of| 00000260 66 20 61 20 57 69 6e 63 68 65 73 74 65 72 20 64 |f a Winchester d| 00000270 69 73 6b 20 69 73 20 70 65 72 6d 61 6e 65 6e 74 |isk is permanent| 00000280 6c 79 20 73 65 61 6c 65 64 20 69 6e 20 69 74 27 |ly sealed in it'| 00000290 73 0d 68 6f 75 73 69 6e 67 20 61 6e 64 20 63 61 |s.housing and ca| 000002a0 6e 6e 6f 74 20 62 65 20 72 65 6d 6f 76 65 64 2c |nnot be removed,| 000002b0 20 65 78 74 72 61 20 63 6f 6e 74 72 6f 6c 6c 65 | extra controlle| 000002c0 72 20 63 69 72 63 75 69 74 72 79 20 69 73 20 61 |r circuitry is a| 000002d0 6c 73 6f 20 6e 65 65 64 65 64 0d 74 6f 20 69 6e |lso needed.to in| 000002e0 74 65 72 66 61 63 65 20 69 74 2e 0d 0d 4d 6f 73 |terface it...Mos| 000002f0 74 20 57 69 6e 63 68 65 73 74 65 72 20 64 72 69 |t Winchester dri| 00000300 76 65 73 20 61 72 65 20 74 68 65 20 73 61 6d 65 |ves are the same| 00000310 20 70 68 79 73 69 63 61 6c 20 73 69 7a 65 20 61 | physical size a| 00000320 73 20 61 20 35 2e 32 35 22 20 66 75 6c 6c 20 68 |s a 5.25" full h| 00000330 65 69 67 68 74 0d 6f 72 20 68 61 6c 66 20 68 65 |eight.or half he| 00000340 69 67 68 74 20 66 6c 6f 70 70 79 20 64 72 69 76 |ight floppy driv| 00000350 65 20 61 6e 64 20 63 6f 6d 65 20 69 6e 20 6e 75 |e and come in nu| 00000360 6d 65 72 6f 75 73 20 73 74 6f 72 61 67 65 20 63 |merous storage c| 00000370 61 70 61 63 69 74 69 65 73 0d 72 61 6e 67 69 6e |apacities.rangin| 00000380 67 20 66 72 6f 6d 20 35 4d 62 20 74 6f 20 61 72 |g from 5Mb to ar| 00000390 6f 75 6e 64 20 31 34 30 4d 62 20 28 31 30 4d 62 |ound 140Mb (10Mb| 000003a0 20 69 73 20 6d 6f 73 74 20 63 6f 6d 6d 6f 6e 20 | is most common | 000003b0 61 6e 64 20 75 73 75 61 6c 6c 79 0d 61 66 66 6f |and usually.affo| 000003c0 72 64 61 62 6c 65 29 2e 20 20 54 68 65 20 64 72 |rdable). The dr| 000003d0 69 76 65 20 77 69 6c 6c 20 68 61 76 65 20 74 68 |ive will have th| 000003e0 72 65 65 20 63 6f 6e 6e 65 63 74 6f 72 73 2c 20 |ree connectors, | 000003f0 70 6f 77 65 72 2c 20 64 61 74 61 20 61 6e 64 0d |power, data and.| 00000400 63 6f 6e 74 72 6f 6c 2e 20 20 54 68 65 20 53 41 |control. The SA| 00000410 53 49 20 28 53 68 75 67 61 72 74 20 41 73 73 6f |SI (Shugart Asso| 00000420 63 69 61 74 65 73 20 53 74 61 6e 64 61 72 64 20 |ciates Standard | 00000430 49 6e 74 65 72 66 61 63 65 29 20 53 54 34 30 36 |Interface) ST406| 00000440 2f 35 30 36 0d 61 70 70 6c 69 65 73 20 74 6f 20 |/506.applies to | 00000450 74 68 65 20 64 61 74 61 20 61 6e 64 20 63 6f 6e |the data and con| 00000460 74 72 6f 6c 20 63 6f 6e 6e 65 63 74 6f 72 73 2c |trol connectors,| 00000470 20 62 61 73 69 63 61 6c 6c 79 20 74 68 65 20 63 | basically the c| 00000480 6f 6e 74 72 6f 6c 0d 63 6f 6e 6e 65 63 74 6f 72 |ontrol.connector| 00000490 20 69 73 20 61 20 33 34 20 77 61 79 20 65 64 67 | is a 34 way edg| 000004a0 65 20 63 6f 6e 6e 65 63 74 6f 72 20 63 61 72 72 |e connector carr| 000004b0 79 69 6e 67 20 73 69 6d 69 6c 61 72 20 63 6f 6e |ying similar con| 000004c0 74 72 6f 6c 20 66 75 6e 63 74 69 6f 6e 73 20 74 |trol functions t| 000004d0 6f 0d 74 68 6f 73 65 20 66 6f 75 6e 64 20 6f 6e |o.those found on| 000004e0 20 61 20 73 74 61 6e 64 61 72 64 20 66 6c 6f 70 | a standard flop| 000004f0 70 79 20 64 69 73 6b 2c 20 61 6e 64 20 74 68 65 |py disk, and the| 00000500 20 64 61 74 61 20 63 6f 6e 6e 65 63 74 6f 72 20 | data connector | 00000510 69 73 20 61 20 32 30 20 77 61 79 0d 65 64 67 65 |is a 20 way.edge| 00000520 20 63 6f 6e 6e 65 63 74 6f 72 20 74 68 61 74 20 | connector that | 00000530 63 61 72 72 69 65 73 20 74 68 65 20 64 61 74 61 |carries the data| 00000540 20 74 6f 2f 66 72 6f 6d 20 74 68 65 20 68 65 61 | to/from the hea| 00000550 64 28 73 29 2e 0d 0d 54 68 65 20 57 69 6e 63 68 |d(s)...The Winch| 00000560 65 73 74 65 72 20 64 69 73 6b 20 63 61 6e 6e 6f |ester disk canno| 00000570 74 20 62 65 20 63 6f 6e 6e 65 63 74 65 64 20 74 |t be connected t| 00000580 6f 20 61 20 6d 69 63 72 6f 20 63 6f 6d 70 75 74 |o a micro comput| 00000590 65 72 20 64 69 72 65 63 74 6c 79 2c 0d 69 6e 73 |er directly,.ins| 000005a0 74 65 61 64 20 61 6e 20 69 6e 74 65 6c 6c 69 67 |tead an intellig| 000005b0 65 6e 74 20 28 6d 69 63 72 6f 70 72 6f 63 65 73 |ent (microproces| 000005c0 73 6f 72 20 62 61 73 65 64 29 20 63 6f 6e 74 72 |sor based) contr| 000005d0 6f 6c 6c 65 72 20 68 61 73 20 74 6f 20 75 73 65 |oller has to use| 000005e0 64 2e 20 20 54 68 65 0d 57 69 6e 63 68 65 73 74 |d. The.Winchest| 000005f0 65 72 20 63 6f 6e 74 72 6f 6c 6c 65 72 20 69 73 |er controller is| 00000600 20 61 20 76 69 74 61 6c 20 70 61 72 74 20 6f 66 | a vital part of| 00000610 20 74 68 65 20 73 79 73 74 65 6d 2c 20 69 74 20 | the system, it | 00000620 69 73 20 6f 70 65 72 61 74 65 64 20 75 6e 64 65 |is operated unde| 00000630 72 0d 73 6f 66 74 77 61 72 65 20 63 6f 6e 74 72 |r.software contr| 00000640 6f 6c 20 6f 66 20 74 68 65 20 68 6f 73 74 20 61 |ol of the host a| 00000650 6e 64 20 70 65 72 66 6f 72 6d 73 20 61 6c 6c 20 |nd performs all | 00000660 74 68 65 20 72 65 61 64 2f 77 72 69 74 65 2f 73 |the read/write/s| 00000670 65 65 6b 2f 66 6f 72 6d 61 74 0d 6f 70 65 72 61 |eek/format.opera| 00000680 74 69 6f 6e 73 20 6f 6e 20 74 68 65 20 57 69 6e |tions on the Win| 00000690 63 68 65 73 74 65 72 20 2d 20 74 68 65 20 68 6f |chester - the ho| 000006a0 73 74 20 68 61 73 20 6f 6e 6c 79 20 74 6f 20 73 |st has only to s| 000006b0 65 6e 64 20 68 69 67 68 20 6c 65 76 65 6c 0d 22 |end high level."| 000006c0 63 6f 6d 6d 61 6e 64 73 22 20 74 6f 20 74 68 65 |commands" to the| 000006d0 20 63 6f 6e 74 72 6f 6c 6c 65 72 20 74 6f 20 62 | controller to b| 000006e0 65 20 61 62 6c 65 20 74 6f 20 75 73 65 20 74 68 |e able to use th| 000006f0 65 20 77 69 6e 63 68 65 73 74 65 72 2e 0d 0d 41 |e winchester...A| 00000700 62 6f 75 74 20 63 6f 6e 74 72 6f 6c 6c 65 72 73 |bout controllers| 00000710 20 61 6e 64 20 61 6c 6c 20 74 68 61 74 2e 2e 2e | and all that...| 00000720 0d 0d 54 6f 20 74 68 65 20 68 6f 73 74 2c 20 74 |..To the host, t| 00000730 68 65 20 57 69 6e 63 68 65 73 74 65 72 20 6a 75 |he Winchester ju| 00000740 73 74 20 6c 6f 6f 6b 73 20 6c 69 6b 65 20 61 20 |st looks like a | 00000750 6c 61 72 67 65 20 6e 75 6d 62 65 72 20 6f 66 20 |large number of | 00000760 73 65 63 74 6f 72 73 20 28 6f 72 0d 62 6c 6f 63 |sectors (or.bloc| 00000770 6b 73 29 2c 20 74 68 65 20 68 6f 73 74 20 69 73 |ks), the host is| 00000780 20 6e 6f 74 20 63 6f 6e 63 65 72 6e 65 64 20 77 | not concerned w| 00000790 69 74 68 20 74 68 65 20 74 72 61 63 6b 2f 63 79 |ith the track/cy| 000007a0 6c 69 6e 64 65 72 2f 68 65 61 64 2f 73 65 63 74 |linder/head/sect| 000007b0 6f 72 0d 6e 75 6d 62 65 72 2c 20 69 74 20 73 69 |or.number, it si| 000007c0 6d 70 6c 79 20 75 73 65 73 20 61 20 44 69 73 6b |mply uses a Disk| 000007d0 20 41 64 64 72 65 73 73 20 28 44 41 29 20 77 68 | Address (DA) wh| 000007e0 69 63 68 20 75 6e 69 71 75 65 6c 79 20 72 65 66 |ich uniquely ref| 000007f0 65 72 73 20 74 6f 20 65 61 63 68 0d 73 65 63 74 |ers to each.sect| 00000800 6f 72 20 28 74 68 65 20 44 69 73 6b 20 41 64 64 |or (the Disk Add| 00000810 72 65 73 73 20 72 61 6e 67 65 73 20 66 72 6f 6d |ress ranges from| 00000820 20 7a 65 72 6f 20 74 6f 20 74 68 65 20 6d 61 78 | zero to the max| 00000830 69 6d 75 6d 20 77 68 69 63 68 20 69 73 20 6e 75 |imum which is nu| 00000840 6d 62 65 72 0d 6f 66 20 63 79 6c 69 6e 64 65 72 |mber.of cylinder| 00000850 73 20 2a 20 6e 75 6d 62 65 72 20 6f 66 20 68 65 |s * number of he| 00000860 61 64 73 20 2a 20 6e 75 6d 62 65 72 20 6f 66 20 |ads * number of | 00000870 73 65 63 74 6f 72 73 20 70 65 72 20 74 72 61 63 |sectors per trac| 00000880 6b 20 2d 20 31 29 2e 20 20 54 68 65 0d 44 69 73 |k - 1). The.Dis| 00000890 6b 20 41 64 64 72 65 73 73 20 69 73 20 72 65 70 |k Address is rep| 000008a0 72 65 73 65 6e 74 65 64 20 62 79 20 61 20 32 34 |resented by a 24| 000008b0 20 62 69 74 20 6e 75 6d 62 65 72 20 28 33 20 68 | bit number (3 h| 000008c0 65 78 20 62 79 74 65 73 29 2c 20 73 6f 20 64 72 |ex bytes), so dr| 000008d0 69 76 65 20 30 0d 68 65 61 64 20 30 20 74 72 61 |ive 0.head 0 tra| 000008e0 63 6b 20 30 20 69 73 20 44 41 20 30 30 30 30 30 |ck 0 is DA 00000| 000008f0 30 2c 20 73 65 63 74 6f 72 20 31 20 69 73 20 30 |0, sector 1 is 0| 00000900 30 30 30 30 31 20 65 74 63 2e 20 74 6f 20 74 68 |00001 etc. to th| 00000910 65 20 65 6e 64 20 6f 66 20 74 68 65 0d 64 69 73 |e end of the.dis| 00000920 6b 2e 20 20 54 68 69 73 20 6e 6f 74 61 74 69 6f |k. This notatio| 00000930 6e 20 69 73 20 76 65 72 79 20 63 6f 6e 76 65 6e |n is very conven| 00000940 69 65 6e 74 20 61 73 20 69 74 20 61 6c 6c 6f 77 |ient as it allow| 00000950 73 20 6d 65 64 69 61 20 69 6e 64 65 70 65 6e 64 |s media independ| 00000960 65 6e 63 65 20 69 6e 0d 74 68 65 20 66 69 6c 69 |ence in.the fili| 00000970 6e 67 20 73 79 73 74 65 6d 2c 20 66 6f 72 20 65 |ng system, for e| 00000980 78 61 6d 70 6c 65 20 61 20 66 6c 6f 70 70 79 20 |xample a floppy | 00000990 64 69 73 6b 20 63 61 6e 20 62 65 20 61 64 64 72 |disk can be addr| 000009a0 65 73 73 65 64 20 69 6e 20 74 68 65 20 73 61 6d |essed in the sam| 000009b0 65 0d 77 61 79 2c 20 69 74 20 6a 75 73 74 20 68 |e.way, it just h| 000009c0 61 73 20 6c 65 73 73 20 73 65 63 74 6f 72 73 20 |as less sectors | 000009d0 73 6f 20 69 74 20 68 61 73 20 61 20 63 6f 72 72 |so it has a corr| 000009e0 65 73 70 6f 6e 64 69 6e 67 6c 79 20 6c 6f 77 65 |espondingly lowe| 000009f0 72 20 6d 61 78 69 6d 75 6d 0d 44 41 2e 0d 0d 41 |r maximum.DA...A| 00000a00 67 61 69 6e 20 74 68 65 72 65 20 69 73 20 61 20 |gain there is a | 00000a10 53 41 53 49 20 73 74 61 6e 64 61 72 64 20 66 6f |SASI standard fo| 00000a20 72 20 63 6f 6e 74 72 6f 6c 6c 65 72 73 2c 20 6f |r controllers, o| 00000a30 72 69 67 69 6e 61 6c 6c 79 20 69 74 20 64 65 66 |riginally it def| 00000a40 69 6e 65 64 20 6f 6e 6c 79 0d 74 68 65 20 65 6c |ined only.the el| 00000a50 65 63 74 72 69 63 61 6c 20 69 6e 74 65 72 66 61 |ectrical interfa| 00000a60 63 65 20 73 69 67 6e 61 6c 73 2c 20 62 75 74 20 |ce signals, but | 00000a70 61 20 64 65 66 61 63 74 6f 20 73 74 61 6e 64 61 |a defacto standa| 00000a80 72 64 20 65 6d 65 72 67 65 64 20 66 6f 72 20 74 |rd emerged for t| 00000a90 68 65 0d 6d 61 6a 6f 72 69 74 79 20 6f 66 20 68 |he.majority of h| 00000aa0 69 67 68 20 6c 65 76 65 6c 20 63 6f 6d 6d 61 6e |igh level comman| 00000ab0 64 73 2c 20 73 6f 20 69 6e 20 6d 6f 73 74 20 61 |ds, so in most a| 00000ac0 70 70 6c 69 63 61 74 69 6f 6e 73 20 63 6f 6e 74 |pplications cont| 00000ad0 72 6f 6c 6c 65 72 73 20 61 72 65 0d 69 6e 74 65 |rollers are.inte| 00000ae0 72 63 68 61 6e 67 65 61 62 6c 65 2e 20 4d 6f 73 |rchangeable. Mos| 00000af0 74 20 63 6f 6e 74 72 6f 6c 6c 65 72 73 20 63 61 |t controllers ca| 00000b00 6e 20 73 75 70 70 6f 72 74 20 74 77 6f 20 77 69 |n support two wi| 00000b10 6e 63 68 65 73 74 65 72 20 64 72 69 76 65 73 0d |nchester drives.| 00000b20 28 63 6f 6e 6e 65 63 74 65 64 20 62 79 20 74 68 |(connected by th| 00000b30 65 20 33 34 20 77 61 79 20 61 6e 64 20 32 30 20 |e 34 way and 20 | 00000b40 77 61 79 20 73 6f 63 6b 65 74 73 29 20 61 6e 64 |way sockets) and| 00000b50 20 70 72 6f 76 69 64 65 20 61 20 35 30 20 77 61 | provide a 50 wa| 00000b60 79 20 73 6f 63 6b 65 74 0d 74 6f 20 74 68 65 20 |y socket.to the | 00000b70 68 6f 73 74 2e 20 20 54 68 69 73 20 73 6f 63 6b |host. This sock| 00000b80 65 74 20 70 72 6f 76 69 64 65 73 20 61 20 62 69 |et provides a bi| 00000b90 20 64 69 72 65 63 74 69 6f 6e 61 6c 20 38 20 62 | directional 8 b| 00000ba0 69 74 20 70 61 72 61 6c 6c 65 6c 20 64 61 74 61 |it parallel data| 00000bb0 0d 70 6f 72 74 20 61 6e 64 20 61 20 6e 75 6d 62 |.port and a numb| 00000bc0 65 72 20 6f 66 20 69 6e 70 75 74 20 61 6e 64 20 |er of input and | 00000bd0 6f 75 74 70 75 74 20 68 61 6e 64 20 73 68 61 6b |output hand shak| 00000be0 69 6e 67 20 73 69 67 6e 61 6c 73 2c 20 74 68 65 |ing signals, the| 00000bf0 73 65 20 54 54 4c 0d 6c 65 76 65 6c 20 73 69 67 |se TTL.level sig| 00000c00 6e 61 6c 73 20 68 61 76 65 20 74 6f 20 62 65 20 |nals have to be | 00000c10 69 6e 74 65 72 66 61 63 65 64 20 74 6f 20 74 68 |interfaced to th| 00000c20 65 20 68 6f 73 74 20 61 6e 64 20 73 6f 66 74 77 |e host and softw| 00000c30 61 72 65 20 70 72 6f 76 69 64 65 64 20 66 6f 72 |are provided for| 00000c40 0d 64 61 74 61 20 49 2f 4f 2e 0d 0d 54 6f 20 62 |.data I/O...To b| 00000c50 65 20 6d 6f 72 65 20 70 72 65 63 69 73 65 20 74 |e more precise t| 00000c60 68 65 20 44 69 73 6b 20 41 64 64 72 65 73 73 20 |he Disk Address | 00000c70 69 73 20 61 63 74 75 61 6c 6c 79 20 61 20 32 31 |is actually a 21| 00000c80 20 62 69 74 20 6e 75 6d 62 65 72 20 77 68 69 63 | bit number whic| 00000c90 68 0d 72 65 70 72 65 73 65 6e 74 73 20 74 68 65 |h.represents the| 00000ca0 20 73 65 63 74 6f 72 20 6e 75 6d 62 65 72 2c 20 | sector number, | 00000cb0 61 6e 64 20 61 20 33 20 62 69 74 20 6e 75 6d 62 |and a 3 bit numb| 00000cc0 65 72 20 77 68 69 63 68 20 72 65 70 72 65 73 65 |er which represe| 00000cd0 6e 74 73 20 74 68 65 0d 64 65 76 69 63 65 20 6f |nts the.device o| 00000ce0 6e 20 74 68 65 20 63 6f 6e 74 72 6f 6c 6c 65 72 |n the controller| 00000cf0 20 28 6f 72 20 4c 6f 67 69 63 61 6c 20 55 6e 69 | (or Logical Uni| 00000d00 74 20 4e 75 6d 62 65 72 2c 20 74 68 65 20 4c 55 |t Number, the LU| 00000d10 4e 20 68 61 73 20 61 20 72 61 6e 67 65 20 66 72 |N has a range fr| 00000d20 6f 6d 0d 30 2d 37 29 2e 20 20 4d 6f 73 74 20 53 |om.0-7). Most S| 00000d30 41 53 49 20 63 6f 6e 74 72 6f 6c 6c 65 72 73 20 |ASI controllers | 00000d40 73 75 70 70 6f 72 74 20 6d 6f 72 65 20 74 68 61 |support more tha| 00000d50 6e 20 6f 6e 65 20 64 65 76 69 63 65 2c 20 66 6f |n one device, fo| 00000d60 72 20 65 78 61 6d 70 6c 65 0d 53 41 53 49 20 63 |r example.SASI c| 00000d70 6f 6e 74 72 6f 6c 6c 65 72 73 20 74 6f 20 73 75 |ontrollers to su| 00000d80 70 70 6f 72 74 20 32 20 57 69 6e 63 68 65 73 74 |pport 2 Winchest| 00000d90 65 72 73 20 6f 6e 6c 79 2c 20 32 20 77 69 6e 63 |ers only, 2 winc| 00000da0 68 65 73 74 65 72 73 20 2b 20 32 0d 66 6c 6f 70 |hesters + 2.flop| 00000db0 70 69 65 73 2c 20 6f 72 20 31 20 57 69 6e 63 68 |pies, or 1 Winch| 00000dc0 65 73 74 65 72 20 61 6e 64 20 31 20 74 61 70 65 |ester and 1 tape| 00000dd0 20 73 74 72 65 61 6d 65 72 20 61 72 65 20 63 6f | streamer are co| 00000de0 6d 6d 6f 6e 2e 0d 0d 45 61 63 68 20 63 6f 6e 6e |mmon...Each conn| 00000df0 65 63 74 69 6f 6e 20 70 6f 72 74 20 6f 6e 20 61 |ection port on a| 00000e00 20 63 6f 6e 74 72 6f 6c 6c 65 72 20 68 61 73 20 | controller has | 00000e10 61 20 4c 55 4e 20 72 65 6c 61 74 65 64 20 74 6f |a LUN related to| 00000e20 20 69 74 20 73 75 63 68 20 74 68 61 74 0d 72 65 | it such that.re| 00000e30 71 75 65 73 74 73 20 66 6f 72 20 49 2f 4f 20 74 |quests for I/O t| 00000e40 6f 20 61 20 4c 55 4e 20 61 72 65 20 63 68 61 6e |o a LUN are chan| 00000e50 6e 65 6c 65 64 20 74 6f 20 61 20 70 61 72 74 69 |neled to a parti| 00000e60 63 75 6c 61 72 20 70 6f 72 74 2e 20 20 53 6f 6d |cular port. Som| 00000e70 65 0d 63 6f 6e 74 72 6f 6c 6c 65 72 73 20 63 61 |e.controllers ca| 00000e80 6e 20 62 65 20 64 61 69 73 79 20 63 68 61 69 6e |n be daisy chain| 00000e90 65 64 20 6f 6e 20 74 68 65 20 53 41 53 49 20 62 |ed on the SASI b| 00000ea0 75 73 20 74 6f 20 6d 61 6b 65 20 75 73 65 20 6f |us to make use o| 00000eb0 66 20 61 6c 6c 20 38 20 4c 55 4e 73 0d 28 74 68 |f all 8 LUNs.(th| 00000ec0 65 20 63 6f 6e 74 72 6f 6c 6c 65 72 20 63 61 6e |e controller can| 00000ed0 20 62 65 20 63 6f 6e 66 69 67 75 72 65 64 2c 20 | be configured, | 00000ee0 62 79 20 6c 69 6e 6b 73 20 6f 72 20 73 6f 66 74 |by links or soft| 00000ef0 77 61 72 65 2c 20 74 6f 20 6d 61 70 20 70 61 72 |ware, to map par| 00000f00 74 69 63 75 6c 61 72 0d 4c 55 4e 73 20 74 6f 20 |ticular.LUNs to | 00000f10 70 61 72 74 69 63 75 6c 61 72 20 64 65 76 69 63 |particular devic| 00000f20 65 73 29 2e 20 20 41 73 20 61 6e 20 65 78 61 6d |es). As an exam| 00000f30 70 6c 65 2c 20 74 68 65 20 44 54 43 20 35 32 30 |ple, the DTC 520| 00000f40 41 20 63 6f 6e 74 72 6f 6c 6c 65 72 20 62 6f 61 |A controller boa| 00000f50 72 64 0d 73 75 70 70 6f 72 74 73 20 32 20 57 69 |rd.supports 2 Wi| 00000f60 6e 63 68 65 73 74 65 72 73 20 61 6e 64 20 32 20 |nchesters and 2 | 00000f70 66 6c 6f 70 70 69 65 73 2c 20 61 63 63 65 73 73 |floppies, access| 00000f80 65 73 20 61 72 65 20 61 73 20 66 6f 6c 6c 6f 77 |es are as follow| 00000f90 73 3a 0d 0d 09 4c 55 4e 20 3d 20 30 09 09 46 69 |s:...LUN = 0..Fi| 00000fa0 72 73 74 20 57 69 6e 63 68 65 73 74 65 72 20 28 |rst Winchester (| 00000fb0 57 69 6e 63 68 65 73 74 65 72 20 70 6f 72 74 20 |Winchester port | 00000fc0 30 29 0d 09 4c 55 4e 20 3d 20 31 09 09 53 65 63 |0)..LUN = 1..Sec| 00000fd0 6f 6e 64 20 57 69 6e 63 68 65 73 74 65 72 20 28 |ond Winchester (| 00000fe0 57 69 6e 63 68 65 73 74 65 72 20 70 6f 72 74 20 |Winchester port | 00000ff0 31 29 0d 09 4c 55 4e 20 3d 20 32 09 09 46 69 72 |1)..LUN = 2..Fir| 00001000 73 74 20 66 6c 6f 70 70 79 20 28 46 6c 6f 70 70 |st floppy (Flopp| 00001010 79 20 70 6f 72 74 20 30 29 0d 09 4c 55 4e 20 3d |y port 0)..LUN =| 00001020 20 33 09 09 53 65 63 6f 6e 64 20 66 6c 6f 70 70 | 3..Second flopp| 00001030 79 20 28 46 6c 6f 70 70 79 20 70 6f 72 74 20 31 |y (Floppy port 1| 00001040 29 0d 0d 55 73 75 61 6c 6c 79 20 61 20 63 6f 6e |)..Usually a con| 00001050 74 72 6f 6c 6c 65 72 20 63 61 6e 20 73 75 70 70 |troller can supp| 00001060 6f 72 74 20 74 77 6f 20 57 69 6e 63 68 65 73 74 |ort two Winchest| 00001070 65 72 73 20 28 61 6c 6c 20 74 68 65 20 6f 6e 65 |ers (all the one| 00001080 73 20 49 20 68 61 76 65 20 6d 65 74 0d 64 6f 29 |s I have met.do)| 00001090 2c 20 62 75 74 20 73 6f 6d 65 20 6f 6e 6c 79 20 |, but some only | 000010a0 61 6c 6c 6f 77 20 74 68 69 73 20 69 66 20 74 68 |allow this if th| 000010b0 65 20 74 77 6f 20 64 65 76 69 63 65 73 20 61 72 |e two devices ar| 000010c0 65 20 6f 66 20 74 68 65 20 73 61 6d 65 20 74 79 |e of the same ty| 000010d0 70 65 20 61 6e 64 0d 63 61 70 61 63 69 74 79 20 |pe and.capacity | 000010e0 6f 74 68 65 72 73 20 61 6c 6c 6f 77 20 74 68 65 |others allow the| 000010f0 20 73 69 7a 65 2f 63 61 70 61 63 69 74 79 20 6f | size/capacity o| 00001100 66 20 65 61 63 68 20 64 72 69 76 65 20 74 6f 20 |f each drive to | 00001110 62 65 20 73 70 65 63 69 66 69 65 64 20 74 6f 0d |be specified to.| 00001120 74 68 65 20 63 6f 6e 74 72 6f 6c 6c 65 72 20 2d |the controller -| 00001130 20 69 74 27 73 20 73 61 66 65 72 20 74 6f 20 75 | it's safer to u| 00001140 73 65 20 6f 6e 65 20 57 69 6e 63 68 65 73 74 65 |se one Wincheste| 00001150 72 20 6f 72 20 74 77 6f 20 6f 66 20 74 68 65 20 |r or two of the | 00001160 73 61 6d 65 20 73 69 7a 65 0d 28 61 20 66 72 69 |same size.(a fri| 00001170 65 6e 64 20 6e 65 61 72 6c 79 20 72 75 69 6e 65 |end nearly ruine| 00001180 64 20 61 20 32 30 4d 62 20 52 6f 64 69 6d 65 20 |d a 20Mb Rodime | 00001190 77 68 65 6e 20 75 73 69 6e 67 20 69 74 20 69 6e |when using it in| 000011a0 20 63 6f 6e 6a 75 6e 63 74 69 6f 6e 20 77 69 74 | conjunction wit| 000011b0 68 20 61 0d 31 30 4d 62 20 52 6f 64 69 6d 65 29 |h a.10Mb Rodime)| 000011c0 2e 0d 0d 54 68 65 72 65 20 61 72 65 20 74 77 6f |...There are two| 000011d0 20 64 69 73 74 69 6e 63 74 20 74 79 70 65 73 20 | distinct types | 000011e0 6f 66 20 66 6f 72 6d 61 74 74 69 6e 67 20 61 20 |of formatting a | 000011f0 63 6f 6e 74 72 6f 6c 6c 65 72 20 63 61 6e 20 75 |controller can u| 00001200 73 65 20 6f 6e 20 61 0d 57 69 6e 63 68 65 73 74 |se on a.Winchest| 00001210 65 72 3a 20 4d 46 4d 20 28 4d 6f 64 69 66 69 65 |er: MFM (Modifie| 00001220 64 20 46 72 65 71 75 65 6e 63 79 20 4d 6f 64 75 |d Frequency Modu| 00001230 6c 61 74 69 6f 6e 29 20 61 6e 64 20 52 4c 4c 20 |lation) and RLL | 00001240 28 52 75 6e 20 4c 65 6e 67 74 68 0d 4c 69 6d 69 |(Run Length.Limi| 00001250 74 69 6e 67 20 2d 20 73 6f 6d 65 74 69 6d 65 73 |ting - sometimes| 00001260 20 6b 6e 6f 77 6e 20 61 73 20 32 2c 37 20 52 4c | known as 2,7 RL| 00001270 4c 29 2e 20 20 42 61 73 69 63 61 6c 6c 79 20 52 |L). Basically R| 00001280 4c 4c 20 69 73 20 74 68 65 20 6e 65 77 65 72 0d |LL is the newer.| 00001290 74 65 63 68 6e 69 71 75 65 20 77 68 69 63 68 20 |technique which | 000012a0 75 73 65 73 20 61 20 74 79 70 65 20 6f 66 20 64 |uses a type of d| 000012b0 61 74 61 20 63 6f 6d 70 72 65 73 73 69 6f 6e 20 |ata compression | 000012c0 74 6f 20 67 65 74 20 6d 6f 72 65 20 64 61 74 61 |to get more data| 000012d0 20 6f 6e 74 6f 20 74 68 65 0d 64 69 73 6b 20 28 | onto the.disk (| 000012e0 61 20 62 69 74 20 6c 69 6b 65 20 75 73 69 6e 67 |a bit like using| 000012f0 20 64 6f 75 62 6c 65 20 64 65 6e 73 69 74 79 20 | double density | 00001300 6f 6e 20 66 6c 6f 70 70 79 20 64 69 73 6b 73 29 |on floppy disks)| 00001310 20 62 75 74 20 72 65 71 75 69 72 65 73 20 61 20 | but requires a | 00001320 64 69 73 6b 0d 63 61 70 61 62 6c 65 20 6f 66 20 |disk.capable of | 00001330 73 75 70 70 6f 72 74 69 6e 67 20 52 4c 4c 20 28 |supporting RLL (| 00001340 74 68 65 20 74 72 61 6e 73 66 65 72 20 72 61 74 |the transfer rat| 00001350 65 20 69 73 20 69 6e 63 72 65 61 73 65 64 20 74 |e is increased t| 00001360 6f 20 61 70 70 72 6f 78 69 6d 61 74 65 6c 79 0d |o approximately.| 00001370 37 2e 35 4d 62 2f 73 29 2e 20 20 41 6c 73 6f 20 |7.5Mb/s). Also | 00001380 74 68 65 20 63 6f 6e 74 72 6f 6c 6c 65 72 20 68 |the controller h| 00001390 61 73 20 74 6f 20 62 65 20 61 62 6c 65 20 74 6f |as to be able to| 000013a0 20 73 75 70 70 6f 72 74 20 52 4c 4c 20 28 65 67 | support RLL (eg| 000013b0 2e 20 41 64 61 70 74 65 63 0d 41 43 42 34 30 37 |. Adaptec.ACB407| 000013c0 30 29 2e 20 20 4d 6f 73 74 20 63 6f 6e 74 72 6f |0). Most contro| 000013d0 6c 6c 65 72 73 20 6f 6e 20 74 68 65 20 73 65 63 |llers on the sec| 000013e0 6f 6e 64 20 68 61 6e 64 20 6d 61 72 6b 65 74 20 |ond hand market | 000013f0 73 75 70 70 6f 72 74 20 6f 6e 6c 79 20 4d 46 4d |support only MFM| 00001400 20 61 6e 64 0d 6d 6f 73 74 20 64 72 69 76 65 73 | and.most drives| 00001410 20 77 65 72 65 20 69 6e 74 65 6e 64 65 64 20 66 | were intended f| 00001420 6f 72 20 75 73 65 20 77 69 74 68 20 4d 46 4d 2e |or use with MFM.| 00001430 20 20 4d 79 20 61 64 76 69 63 65 20 69 73 20 74 | My advice is t| 00001440 6f 20 73 74 69 63 6b 20 77 69 74 68 0d 4d 46 4d |o stick with.MFM| 00001450 20 75 6e 6c 65 73 73 20 79 6f 75 20 72 65 61 6c | unless you real| 00001460 6c 79 20 6e 65 65 64 20 74 68 65 20 65 78 74 72 |ly need the extr| 00001470 61 20 73 70 61 63 65 20 2d 20 61 6c 73 6f 20 69 |a space - also i| 00001480 74 27 73 20 70 72 6f 62 61 62 6c 79 20 63 68 65 |t's probably che| 00001490 61 70 65 72 20 74 6f 0d 75 73 65 20 61 20 62 69 |aper to.use a bi| 000014a0 67 67 65 72 20 64 72 69 76 65 20 77 69 74 68 20 |gger drive with | 000014b0 4d 46 4d 20 74 68 61 6e 20 74 6f 20 70 75 72 63 |MFM than to purc| 000014c0 68 61 73 65 20 61 20 52 4c 4c 20 63 6f 6e 74 72 |hase a RLL contr| 000014d0 6f 6c 6c 65 72 2e 0d 0d 43 6f 6e 74 72 6f 6c 6c |oller...Controll| 000014e0 65 72 73 20 61 72 65 20 6e 6f 74 2c 20 75 6e 66 |ers are not, unf| 000014f0 6f 72 74 75 6e 61 74 65 6c 79 2c 20 69 6e 74 65 |ortunately, inte| 00001500 72 63 68 61 6e 67 65 61 62 6c 65 2e 20 20 54 68 |rchangeable. Th| 00001510 61 74 20 69 73 20 61 20 57 69 6e 63 68 65 73 74 |at is a Winchest| 00001520 65 72 0d 74 68 61 74 20 68 61 73 20 62 65 65 6e |er.that has been| 00001530 20 66 6f 72 6d 61 74 74 65 64 20 62 79 20 6f 6e | formatted by on| 00001540 65 20 63 6f 6e 74 72 6f 6c 6c 65 72 20 63 61 6e |e controller can| 00001550 6e 6f 74 20 62 65 20 72 65 61 64 20 6f 72 20 77 |not be read or w| 00001560 72 69 74 74 65 6e 20 74 6f 20 62 79 0d 61 20 64 |ritten to by.a d| 00001570 69 66 66 65 72 65 6e 74 20 6d 61 6b 65 20 6f 66 |ifferent make of| 00001580 20 63 6f 6e 74 72 6f 6c 6c 65 72 2e 20 20 54 68 | controller. Th| 00001590 69 73 20 69 73 20 62 65 63 61 75 73 65 20 74 68 |is is because th| 000015a0 65 20 64 69 66 66 65 72 65 6e 74 20 63 6f 6e 74 |e different cont| 000015b0 72 6f 6c 6c 65 72 0d 6d 61 6e 75 66 61 63 74 75 |roller.manufactu| 000015c0 72 65 72 73 20 75 73 65 20 73 6c 69 67 68 74 6c |rers use slightl| 000015d0 79 20 64 69 66 66 65 72 65 6e 74 20 6d 65 74 68 |y different meth| 000015e0 6f 64 73 20 6f 66 20 70 75 74 74 69 6e 67 20 74 |ods of putting t| 000015f0 68 65 20 64 61 74 61 20 6f 6e 74 6f 20 74 68 65 |he data onto the| 00001600 0d 64 69 73 6b 2c 20 64 69 66 66 65 72 65 6e 74 |.disk, different| 00001610 20 6e 75 6d 62 65 72 73 20 6f 66 20 73 65 63 74 | numbers of sect| 00001620 6f 72 73 20 70 65 72 20 74 72 61 63 6b 20 65 74 |ors per track et| 00001630 63 2e 0d 0d 41 6e 6f 74 68 65 72 20 63 6f 6d 70 |c...Another comp| 00001640 61 74 69 62 69 6c 69 74 79 20 22 70 72 6f 62 6c |atibility "probl| 00001650 65 6d 22 20 77 69 74 68 20 63 6f 6e 74 72 6f 6c |em" with control| 00001660 6c 65 72 73 20 69 73 20 68 6f 77 20 74 68 65 79 |lers is how they| 00001670 20 61 72 65 20 69 6e 66 6f 72 6d 65 64 0d 61 62 | are informed.ab| 00001680 6f 75 74 20 74 68 65 20 73 69 7a 65 2f 73 68 61 |out the size/sha| 00001690 70 65 20 6f 66 20 74 68 65 20 57 69 6e 63 68 65 |pe of the Winche| 000016a0 73 74 65 72 20 61 74 74 61 63 68 65 64 2e 20 20 |ster attached. | 000016b0 20 41 6c 6c 20 63 6f 6e 74 72 6f 6c 6c 65 72 73 | All controllers| 000016c0 20 68 61 76 65 20 61 0d 22 64 65 66 61 75 6c 74 | have a."default| 000016d0 22 20 64 72 69 76 65 20 63 6f 6e 66 69 67 75 72 |" drive configur| 000016e0 61 74 69 6f 6e 20 61 74 20 70 6f 77 65 72 20 75 |ation at power u| 000016f0 70 20 28 75 73 75 61 6c 6c 79 20 61 20 53 68 75 |p (usually a Shu| 00001700 67 61 72 74 20 35 4d 62 20 64 72 69 76 65 29 0d |gart 5Mb drive).| 00001710 77 68 69 63 68 20 69 73 20 6e 6f 74 20 6d 75 63 |which is not muc| 00001720 68 20 75 73 65 20 75 6e 6c 65 73 73 20 79 6f 75 |h use unless you| 00001730 20 68 61 70 70 65 6e 20 74 6f 20 62 65 20 75 73 | happen to be us| 00001740 69 6e 67 20 74 68 69 73 20 74 79 70 65 20 6f 66 |ing this type of| 00001750 20 64 72 69 76 65 2e 2e 2e 0d 33 20 77 61 79 73 | drive....3 ways| 00001760 20 61 72 6f 75 6e 64 20 74 68 69 73 20 70 72 6f | around this pro| 00001770 62 6c 65 6d 20 61 72 65 20 75 73 65 64 3a 0d 0d |blem are used:..| 00001780
F/+HARD1.m0
F/+HARD1.m1
F/+HARD1.m2
F/+HARD1.m4
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.