How to improve your logic in programming?
In these dedicated programming books, you will find many solved examples that can help buyers improve their programming logic. The basics of programming can never be changed and you can test the programming logic using programming guides. It would be helpful if you also tried all the examples with your initiative and logic.
Many computer users have found or heard that some computers will not boot from a floppy, hard drive, or CD if their so-called lock logic is built into the hard drive. So what is a “logical lock”?
The so-called “disk lock” is done by some bug in some DOS. He uses all the technology”Circular partition table” logic, so some buggy DOS fails https://doslogic.com boot on all devices, including floppy disks and various mobile devices. When starting DOS, the system automatically looks for specific information about each partition on its own drive, such as type, level, etc., so that the system can safely identify the drive, assign C, D, E, F, and other drives to them, and enable them must be friendly to perform various operations with it. “Logical lock” takes advantage of the positive aspect of this by partitioning all tables on disk in such a way that it splits the table cycle where the first logical disk of the extended partition points to par, so some DOS systems are also due to the world and cannot start a death cycle when displaying partitions.
You can see that this is actually caused by a specific error when starting DOS. It should be noted that in 1992, a major anti-virus expert named Mike discovered the above problem and reported this problem to DOS manufacturers such as Microsoft, Microsoft services producing MS-DOS, etc. Soon after,According to IBM, Novell and other companies said that a new version of their own DOS completely solved this serious problem. Only Microsoft with MS-DOS ignores anything related to MS-DOS in the new version, like 6x 7.x etc. this problem still exists.
However, Microsoft uses MS-DOS the most, so it has the most perception and damage. A single user’s weak drive is locked by its “logical lock” in various Microsoft operating systems such as MS-DOS #5x/6. x/7. Boot disks from X and 8.0 etc. won’t boot at all, giving the illusion of a hardware failure and sometimes even confusing many experts. The phenomenon is very terrible and makes computers unusable, many men and women need prevention and solutions. It’s actually not hard to decide. Here are some solutions. Maybe
It can be seen from the above that “logical disk lock” mainly affects the Microsoft MS-DOS system. So the program is allowed to use a different DOS to boot. For this reason, I specifically did a boot test of various practical and later versions of DOS, such asMS-DOS version 7.10, PC-DOS version 7.10, dr-dos version 7.05, rom-dos version 7.10, FreeDOS version 7.10, FreeDOS version 7.10, FreeDOS version 7.10. from 9 and pts-dos pts-ds Consultant 2000 with a “logic lock” inside the hard drive. Either way, the results will look like this:
PC-DOS 7.10 boot disk: everything starts normally;
Dr-dos boot disk} 7.05 (version number: 7.10): everything starts normally;
Rom-dos boot disk number 7.10: everything is fine ;
FreeDOS # beta 9 (version number: 7.10): on startup it usually says a hard disk error is not simple and starts up quite normally;
pts-dos-number pro # 2000 (version number: 6.90): Everything starts up normally.
Note. The above DOS is very stable and supports FAT32 partitions and large disks. Rom-dos # 7. Also 10 supports fully locally expanded filenames and has pretty good compatibility.
How to prevent DoS attacks?
By installing security patches, you can reduce the risk of such attacks. It is also possible to purchase intrusion detection systems to detect and even suppress prohibited activities. Firewalls can be used directly to stop simple DoS attacks by dropping all traffic from an enemy by identifying its IP address.
Thus “logically locked” hard drives can be booted from multiple DOS boot drives, a fixed drive letter that was later locked at boot (e.g. C:), although you may well come across various hard partitioning tools A lawsuit such as Norton. Disk Editor 2005, Norton Disk Doctor 2002, and all DOS fdisk programs that allocate a locked drive. Up to this point, you can either browse the repair disk, which contains the above diskedit and other stuff, manually for each individual disk, or automatically repair it with some software like netresq and betten RCtools, etc. “logical lock ” on the hard drive completely and the data on the problematic hard drive will not be damaged.
While an MS-DOS boot floppy might not be able to boot this particular computer if the hard drive is properly locked under normal circumstances, it is usually only the boot I/O file that is associated with the MS-DOS A-Bug error in sys. one After actually fixing the error, the MS-DOS boot disk is not affected by the “logical lock” type and can boot normally. But even if you are an insect, you must follow the right path. Someone mentioned that when trimming and editing io, the system disk partition is marked as “55AA” to solve the real problem. Actually thisthe method is certainly very bad. Because this method simply causes Sys io to completely ignore the presence of a hard drive, it boots up a blank drive, skipping the hard drive. So, whether a particular drive is locked or not, the drive cannot be well recognized once booted from that new drive, so that boot drive cannot be used as an MS-DOS boot drive. On the other hand, if to fix io. For the pest in sys, after loading your floppy, if the hard disk is ok, it can be found normally, even if the hard disk or DVD is locked by “logical lock”, you can also use the scheme below (i.e. “boot from the operating non-MS-DOS system”) dos, FreeDOS, pts-dos} pro and other boot disks to fix them after booting. It has also been mentioned that some earlier versions of MS-DOS, such as any version 3.2 boot disk, will be used to boot the computer.But this obviously has many drawbacks.Firstly, it will be difficult to find an old version of DOS.Secondly, its alternative is too m low, with few parts and poor compatibility; Thirdly, under DOS, these products do not store large disks (even 32m are actually not supported), logical partitions, etc. can even lead to actual disk damage. Also, MS-DOS 3.2 and other versions may not even be aware of the 1.44 MB floppy disk. It can be seen that the practice of starting from a lower MS-DOS entry is not very practical. Therefore, it is very important to use a good method to fix the io.sys error of a particular higher version of MS-DOS. Take this six to eight ï¼¾ MS-DOS boot disk. X, for example, any hex editor (like pctools, etc.) can find the hex group “07 ï¼¾ 72 ï¼¾ 03” in the io.sys file and replace it with the new last “03” with “06”. Other MS-DOS modules may also use similar methods. For specific modification methods related to io.sys in MS-DOS 7.10, please refer to the China DOS Alliance forum. The hard disk is locked, as in other DOS systems, thanks to a “logical lock”.