SYSRES For PET/CBM
SYSRES claims to be the "ultimate program manipulation system." Like its predecessors, the Toolkit and BASIC Aid, SYSRES is a programmer's aid package. SYSRES "wedges" into BASIC and adds 33 commands (including six improved BASIC commands) plus 11 extended DOS Support (the original "Wedge") commands. All of the commands are used for the development and maintenance of BASIC programs.
The primary tools needed by a programmer are: auto line numbering, renumbering, find, and trace. SYSRES supplies "deluxe" versions of all these. Automatic line numbering provides the line numbers when typing in a program. If you start at line 100, it will automatically print 110 when you press RETURN on line 100 (assuming a step size often). SYSRES permits as unique variation: automatic statement generation. If you are typing in a long set of DATA statements, SYSRES can provide the line numbers and the word "DATA." SYSRES offers a "fill in the blank" line where you only need to enter a single number. It can even press RETURN for you, giving it the capability for automatic line entry.
Most Renumber commands change the line numbers of a BASIC program by an even increment and update all line references made by GOTO, THEN, GOSUB, etc. The entire program is renumbered. SYSRES permits partial renumber. You can renumber just a subroutine, for example, preserving all other line numbers, and updating any line references if necessary.
Perhaps the most useful command in a package like this is a Find command. Many programmers find it indispensable. Using Find, you can locate any variable, phrase, or keyword used anywhere in your program. Another related command is Change, which permits you to replace any variable, phrase, or keyword with anything else.
For the Change command especially, it is vital that you exactly specify the search string. You may want to change A$ to B$, but you don't want ZA$ to become ZB$. To zero in on whatever you are searching for, SYSRES permits you to use several wild card and limitation symbols (such as V for Variable, B for Beginning of line, or a quote to signal quote mode), which together permit over 700 possibilities.
Debugging a program is much easier with a Trace command. Trace (as implemented by SYSRES) permits you to display program variables as they change or are defined. So, you could display the index of a FOR/NEXT loop, or watch how certain variables interact. (You can also type DUMP in direct mode to display all variables.)
The advanced editor commands let you use the BASIC editor as a general purpose ASCII line editor. The commands GET and PUT let you save this ASCII file to disk. SYSRES even partially tokenizes this file to save disk space. These ASCII files can be used to develop EXEC files, which are a sequence of direct commands that are executed as if they were a program. This gives the PET/CBM the power found formerly only in CP/M's .EXC files, Apple's EXEC files, or Atari's ENTER files. An important feature of EXEC files is that they use no program memory as they execute.
When using SYSRES, you get a feeling that careful design went into the system. All keys repeat, and the cursor keys "take off" quickly. Full up/down scrolling of your BASIC program is supported, and it works perfectly. If you display the directory with the improved ">$0" command, these line numbers cannot be accidentally entered as program lines or activate the scrolling feature.
Full printer support is also included with full ASCII translation. Any command can be sent to the printer if preceded with an asterisk. For example, *LIST would list a program to the printer. You can also dump the screen by holding down both SHIFT keys and pressing RVS. Speaking of keys, with SYSRES you can define any shifted key to equal any sequence of keys or keywords. When you define any key, all the alphabetic keys "come alive" with convenient single-key abbreviations.
Improvements To BASIC Itself
The improved BASIC commands are another example of the care taken to produce a complete "operating system." The LOAD, SAVE, and VERIFY commands default to the disk drive, and the save with replace ("@") works on any disk drive. (It first SCRATCHes, then resaves the program.) Nevertheless, none of the commands are programmable. Therefore, programs developed with SYSRES are fully transportable As the manual says, "SYSRES is designed to be ‘addictive to programmers not to programs.’ "
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