DOS

One of the real bargains on IBM's software shelf is their Disk Operating System (DOS) for the Personal Computer. For $40 you get a system which is about equivalent to CP/M in feature, and which includes both Disk and Advanced Basic. Also included on the disk are three software development tools: DEBUG, a memory-based debugger; EDLIN, a line oriented text file editor; and LINK, IBM's language link editor. DEBUG and LINK will only be of interest to system developers, and I will not detail them here. EDLIN is useful in general, but it is so simple to learn and use that I'll leave it as an exercise (I always wanted to say that). I have been told that some Basic programs will also be included to serve as programming examples. I was also told that these would be the dealer demos.

Table 5 lists the DOS commands and the functions they perform. Here again I have little upon which to comment. I will mention that I timed FORMAT, DISKCOPY, and DISKCOMP commands. Formatting a disk took 34 seconds. Disk copying required 52 seconds. Disk copying using only one diskette drive required one minute and 38 seconds, and required 4 disk manipulations. Disk comparison required 33 seconds. All these times are quite reasonable. I will also mention that I was impressed with the "smoothness" of operation of DOS. Messages and prompts were very clear and I was never at a loss for what to do next. The only problem I encountered was in the DISKCOMP program, which refused to let me abort it, and placed the system into a state which could not be cleared by anything less than a power up sequence (ALT-CTRL-DEL would not do it I had to hit the red switch!) Nothing else I did caused any problems.

 

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