Fundemantal questions about using LDR vs Upload DIR with LDR option

[osity]

I can get by by trying one or the other but I would like to know when exactly should I use just the "LDR File Loading" as opposed to "Upload dir into HDD RAM" with LDR option checked.

Since "Upload dir into HDD RAM" with LDR option checked load more files why wouldn't I want to use this all the time when I want to load the loader?

[Amarbir[CDR-Labs]]

Source of the post I can get by by trying one or the other but I would like to know when exactly should I use just the "LDR File Loading" as opposed to "Upload dir into HDD RAM" with LDR option checked.

Since "Upload dir into HDD RAM" with LDR option checked load more files why wouldn't I want to use this all the time when I want to load the loader?

Hi osity ,
Once The Drive Loads Code From MCU on The PCB It Then Reads The Code in Rom Once That Code Executes It Parses modules in rom and then tried to load overlay modules from platter like mod 11 ,mod 5c , mod 13 etc .Overlays are nothing but more code of firmware that loads into ram and executes ,This code is responsibly to load other modules and parse them also .Once we block access to SA it means that nothing from platters are read .So we first have to load mod 11 and other overlay mods called loaders in data recovery terminology .so if you just load loaders and try to read modules you cannot because in ram there is no table that tells where the modules on platter are hence you should read dir module 01 and then load that read module into ram memory so that you can read other modules ,I hope this is clear if it is kindly increase my reputation by 1 please

[osity]

Hi thanks for your response. My question is why I would use one method over the other.

[Amarbir[CDR-Labs]]

Source of the post Hi thanks for your response. My question is why I would use one method over the other.

Well,
I explained That Only .If You Use dir loading into ram then only you get module access not by loading the loader only

[osity]

...so why not just use "Upload dir into HDD RAM" with LDR option checked every time since you get it all? That is basically what I want to know..

[AJ2008]

Most drives when not operating correctly will not upload directory table to RAM so attempting to load its native loader from SA will be unsuccessful unless dir is loaded to RAM first. So upload DIR to RAM and LDR upload is needed in cases where you need to load native loader from patient SA. If this dir table is not loaded then module address references will be incorrect.

Upload LDR without loading DIR is useful when you have loader saved to file and do not need to load from its own SA. Other situations would be if you are using donor ROM & resources to reach patient SA, or if native LDR is damaged or unreadable.

If you plan on reading SA module, even without loader loaded and reading via 'ID' not 'ABA', then dir table must be loaded to be sure modules are referenced at correct address. If this is not done probably you will encounter many checksum errors in modules during reading.

I hope this explains the difference between the two methods.

[osity]

Hi AJ2008, thanks for the response.
So are you saying that "upload dir into HDD RAM" with LDR checked uses the drives internal loader files that it tries to pull directly from the HDD..... and the "LDR File Loading" option would instead pull it from an external source?

Would it be correct to conclude that if you have backed up the resources of the patient (including module 01), there would be no need to use "upload dir into HDD RAM" with LDR checked and just using "LDR File Loading" would suffice?

[AJ2008]

So are you saying that "upload dir into HDD RAM" with LDR checked uses the drives internal loader files that it tries to pull directly from the HDD..... and the "LDR File Loading" option would instead pull it from an external source?

Yes.

if you have backed up the resources of the patient (including module 01), there would be no need to use "upload dir into HDD RAM" with LDR checked and just using "LDR File Loading" would suffice?

If loading LDR alone gives access to SA modules at ABA mode, then yes, but if ABA is not available you would need to load DIR to allow good reading of SA via ID read mode.

[DataMedics]

Also sometimes you may have already loaded the LDR but due to making changes to module locations in the DIR you need to upload a new copy for writing modules to their new locations. In this case you wouldn't need to, or want to, upload LDR again. So you would leave it unchecked in that case.

[AJ2008]

I sometimes need to modify DIR address to make a donor suitable for hotswap, in this case I need to read SA from donor, then load patient DIR table and adjust ROM regions at 0B/20B then I can change address.

During address change I would need to upload LDR but loading from SA would be impossible as locations would be inaccurate.

I guess there are many situations where one or the other is preferred or required. It is just nice to have the multiple options available

[osity]

Are you guys checking to see the hdd's currently loaded modules before determining which option to use?
I've always just used one and if I didn't get the desired result (with access to dir) I'd use the other.

[Amarbir[CDR-Labs]]

Source of the post Are you guys checking to see the hdd's currently loaded modules before determining which option to use?
I've always just used one and if I didn't get the desired result (with access to dir) I'd use the other.

Well,
I Will Give Up n You for This If AJ Is Interested He Can Take this discussion Further ?

[osity]

Source of the post but due to making changes to module locations in the DIR you need to upload a new copy for writing modules to their new locations

why wouldn't you just to restart the utility to refresh the new location instead of loading dir manually?

[DataMedics]

Source of the post

Source of the post but due to making changes to module locations in the DIR you need to upload a new copy for writing modules to their new locations

why wouldn't you just to restart the utility to refresh the new location instead of loading dir manually?

For drives with a lot of SA damage, reloading the utility can be problematic at times. Especially when the module you need to move is the Dir module.

[AJ2008]

why wouldn't you just to restart the utility to refresh the new location instead of loading dir manually?

Connect a bad drive to PC3000 and view the directory module in RAM under 'static modules' and check it. CS will be bad, table will be bad and comparison to the actual table at SA will show many differences. This table is the one the drive is using once it is started. Once this false table has been loaded to RAM it will not refresh after loading a loader externally, only when reloaded manually.

At some cases after loading external loader only without refreshing dir table in RAM you can reach SA by ABA and it will be fine, but maybe it would be better knowing the loaded table is accurate.