5/29/2023 0 Comments Xojo instrThe STOP command, typically used for debugging, allowed an optional following string that was printed out when that statement was performed. RUN started execution, and could be directed to a particular line, as in RUN 100. Working with disk storage was slightly more complex, using LOAD DC F "filename", where F referred to one of a number of pre-defined drives, in this case "F"ixed. BACKSPACE was the opposite of SKIP, rewinding the file pointer. SKIP 2F would read over the next two files found on the cassette tape, and then stop, allowing a subsequent LOAD or SAVE to work on the third file. SAVE "filename" saved the current program to cassette and LOAD "filename" read it back in. When paused, pressing the EXEC key displayed the next 15 lines. LIST was used to display the program source code, while LIST S displayed only the first 15 lines and then paused. To aid organizing large programs, the language included a RENUMBER command. Lines could be up to 192 characters, spanning several on-screen lines, and lines could contain multiple statements separated by colons. Like most BASIC interpreters, Wang BASIC operated in immediate mode or program mode, switching to the later when a line number is seen at the start of the line when the EXEC (return) key is pressed. The original Wang BASIC for the 2200 is a relatively standard version of the Dartmouth BASIC concept, and will be familiar to users of any common BASIC interpreters like Microsoft BASIC. Not all of the instructions listed below would be available in the base model 2200B and C added dozens of new keywords, and are outlined separately below. The following description is based on the original BASIC found in the 2200A. It lacked many features common to later dialects like Microsoft BASIC, but many of these features were added in BASIC-2. A notable feature was that all math used double-precision binary-coded decimal (BCD) format, which was unusual for BASICs of the era. Wang BASIC closely followed the original Dartmouth BASIC in syntax, but was an interpreter as opposed to a compile-and-go system. For instance, the B model machines differed from the base-model A by doubling the ROM and using that to store a variety of input/output and file management commands. Wang offered several models of each version of the 2200 series, differing only in the amount of microcode stored in read-only memory (ROM), and thus the number of commands available in BASIC on that machine. When these machines were updated to the VP series in 1976, BASIC-2 was introduced and remained the pattern for future machines in the 2200 series. The term can be used to refer to the BASIC on any Wang machine, but is mostly associated with the versions on the Wang 2200 minicomputer series of the early 1970s. Wang BASIC is a series of BASIC programming languages for computers from Wang Laboratories.
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