TRACKSALVE TrackSalve is made to improve the Trackdisk device. TD has some problems and lacks some options. As far as I know there are two bugs, from which one is very bad if more than one drive is connected. SetPatch 1.3.2 tries to do something about it, but it is not enough. There are people who do not like the sound of an empty drive. Trackdisk cannot handle a track with an error on it. Then all data on that track is lost. We never know whether the just written data is well stored on disk. And yet we are poking in Trackdisk, we can just as well make a drive optional readonly. FUNCTIONS As already stated, TrackSalve can perform five functions: 1. Bugs patched. he patch of the bugs (as far as I know them). These are the TD_RAWREAD/TD_RAWWRITE bug and the NoDisk routine (oef!). Now it is save to do I/O on one drive and let all your other drives empty. 2. Noclick. Can be switched on and off for each drive apart. I think the situation is as follows: Some drives have an electrical switch at the home position to prevent stepping below zero. Other types have a mechanical stop. These you cannot get them completely silent. I think it is save to use noclick on the first. For those with a mechanical stop I would not switch noclick on. 3. Readonly simulation. Each drive can act as if the tab of the inserted disk is open. This is not as simple as it sounds. The FileSystem (DOS) keeps track of disk swapping. And it asumes that you are not able to shift the tab while a disk is in the drive. Therefore IF there is a disk in the drive AND its tab is closed (write-enabled), and the drive is swithed over to read-only or read/write, a DiskChange is sent out. This is very unfriendly during a write, so this is delayed until the motor is switched off. Nevertheless switch a drive from r/w to ro or back only when it is quiet. 4. TrackSalvage. If Trackdisk gives up on a track, this function (if enabled) comes to action. The track is read again and analised. All unsuspicious data is recovered and stored in Trackdisk's buffers. If the requested data is recovered, no error is passed to the calling task. But an attempt to write to this track is denied and results into a diskerror. So faulting tracks are readonly. 5. Verify. TrackSalve can read back a just written track to check whether the data well arrived on disk. It reads the track into a special buffer which is compared with the original write buffer. Since the Amiga is multitasking, it is not possible to know which task should be notified about an error. Therefore it is the user who must decide about this. He can choose between rewrite and ignore. Rewrite writes the original buffer again to disk, and ignore as if we never knew about the bad track. It may be that subsequent rewrites does not lead to a good result. At least the fact is known that something is wrong. COMMANDLINE If anywhere on the command line one of the chars h, H, or ? are found, the whole command line is ignored and nothing is done but a small usage explanation is printed: Syntax: TrackSalve { {}} Function: Modify a Trackdisk device unit addressed by its unit number Show present status Units: 0-3 Unit(s) Succeeding commands are applied to listed units a All: Succeeding commands are applied to all TD units ! Warning Suppress error if the following unit does not exist Commands: TD in RAM: No special functions, just all known bugs removed s SectorDisk: Change TrackDisk into a sector based disk device t .TrackDisk: Normal: Let TD report errors from a bad track n NoClick: Perform noclick on the unit(s) c .Click: Normal: No noclick r ReadOnly: Make unit read-only, simulate open disk-tab w .WriteEnable: Normal: Unit is read/write according to disk-tab v Verify: Read written track back and compare b .Believe: Normal: Asume track is written well o Original: Let TD execute in its original ROM code / Separator: F.e. "0/2n" Units 0 and 2 in RAM, noclick only on 2 ? Explain: If given (anywhere), no commands are executed Comma's, spaces and dashes are completly ignored. Characters which are not defined lead to an abortion of the program without executing any function. This will be emphasised by a message via standard out. Abortion always has a return value of 20. Units You must address an unit by its number instead of its DOS-name. This is because we are modifying an Exec-device and not a DOS-device. This device has nothing to do with DOS. DOS uses it, and builds a system around it. The name of this system is for example "DF0:". Valid numbers are 0, 1, 2, 3, a and A or any combination of them. 'A' means all units. Commands are single characters. Before you give a command you must specify one or more units to apply the command to. A command will be passed to all directly preceding listed units. If a unit is given that does not exist, then this is an error and nothing will be done at all. It can come handy if it is possible to give a unit that does not exist. Normal would be aborted with return code 20. But if a '!' is put before a possible non-existing unit, a message is printed and the program continues normally, but returns 5. Commands Just a list of units and no commands results in the execution of Trackdisk in RAM with repaired bugs. "TrackSalve a" or "TrackSalve 023". Commands are applied only to preceding units. F.e. TrackSalve 01n lets units 0 and 1 stop clicking. Now you can add new unit numbers like: TrackSalve 01n2r1s. This results into noclick on units 0 and 1, unit is 2 readonly and unit can salve tracks. It is also possible to give contradictory commands: TrackSalve an1c lets all units except 1 noclicking. The separator '/' is a donoting command or "unit list reset". TrackSalve 012/2n lets the units 0, 1 and 2 execute in ram, but noclick is only performed by unit 2. Reset to a defined state can be done by TrackSalve ao followed by the new state. TrackSalve without any parameters prints the present situation and changes nothing. HOW TO USE IT Although Disksalv works well without, both programs work very well together. Disksalv with TrackSalve will generally operate faster and more clearly. It also is possible (not yet happened) that the combination can salve more data. Sometimes only one file is the effort of salvage worthy, like the latest modification not yet on a backup. Now there is a chance that the file can be saved with copy. Might save some time. Then it is possible that immediately after disk insertion a requester appears with "unreadable" and "diskdoctor" or so. There is a fair chance that with TrackSalve these requesters stay away and the disk will be accepted as a DOS disk. You can do more in that case. IMPLEMENTATION The Trackdisk code will be copied from the operating system program and modified and extended. For each unit apart, the unit task can execute this code or stay with the original in ROM. If a unit cannot be brought to execute the patched code, this is told in a message on standard out and the program will continue normally but its return value will be 10. There are two functions which use a buffer of about 26k. If not available at the moment of enabling, every 2.5 second this is tried to allocate again. Until the allocation is successful, the function becomes not active. This is reported through a message and the return value will be 10. Execute TrackSalve without parameters to be sure the function became active. This buffer is shared among all tasks. Normally this will work smoothly and without delay except when a requester is displayed. The requester is used when a verify error has been detected. If for some reason it is not possible to pop up a requester, TrackSalve will loop rewriting the track and blink the drive's led until the conditions have changed. These are: 1. The disk is removed. 2. The track is found well on disk. 3. There is enough memory to display the requester. COPYRIGHT Copyright (c) 1990 D.W. Reisig. This program may be distributed on non-commercial base. This program may not be distibuted on commercial base without my permission. D.W. Reisig Woudweeren 10 1151 AV Broek in Waterland Holland