![]() ![]() ![]() On early hardware, retrying a disk read error would sometimes be successful, but as disk drives improved, this became far less likely. "Retry" was what the user did if they could fix the problem by inserting a disk and closing the disk drive door. Retry ( R): Attempt the operation again.In hindsight, this was not a good idea as the program would not do any cleanup (such as completing writing of other files). Abort ( A): Terminate the operation or program, and return to the command prompt.Users could press a key to indicate what they wanted to happen available options included: Other problems (in particular, a checksum error while reading data from a disk) were also defined as a "critical error", thus causing the prompt to appear for reasons other than a missing disk or opened disk drive. The default "critical error handler" was part of COMMAND.COM and printed the "Abort, Retry. The prompt was invented for this reason.Ī missing disk (or disk drive door opened) was defined by DOS as a "critical error" and would call the "critical error handler". Still, it was desirable to improve the experience, in particular by giving the user a way to get out of the hang without having to find a disk to insert in the drive. Even the first IBM PC had hardware that told the operating system that the disk drive door was open, but returning an error to software trying to read the disk would break the ability to manage disks this way without such changes. ![]() Many users of CP/M became accustomed to this as a method of managing multiple disks, by opening the disk drive to stop a program from reading or writing a file until the correct disk could be inserted.Ī primary design consideration for PC DOS was that software written for CP/M be portable to DOS without changes. In CP/M, attempting to read a floppy disk drive with the door open would hang until a disk was inserted and the disk drive door was closed (very early disk hardware did not send any kind of signal until a disk was spinning, and a timeout to detect the lack of signal required too much code on these tiny systems). Although welcomed by some, the message also has been cited as an example of poor usability in computer user interfaces. " Abort, Retry, Fail?" (or " Abort, Retry, Ignore?") is an error message found in DOS operating systems, which prompts the end-user for a course of action to follow. MS-DOS prompts "Abort, Retry, Fail?" after being commanded to list a directory with no diskette in the drive using the dir command. ![]()
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