PostScript has remained for most people that mysterious “something” in a laser printer that may or may not be hardware, software, or even a bizarre high-tech hybrid of the two. And as most fledgling PostScript hackers know all too well, this state of ignorance has been painfully mirrored by an almost complete lack of tools for PostScript programming.
Unlike established programming languages, PostScript has often been relegated to the backstage, hidden behind the curtains. It's possible to dawdle with it in JustText, Cricket Draw, and Adobe Illustrator but without the benefit of any of the usual debugging features of traditional programming languages, Lasertalk (from the delightfully named Emerald City Software) has changed all that. Lasertalk is not just another collection of PostScript special effects for desktop publishers, like Laser F/X or LaserCraft (see MacUser, January '88, “Well, Isn’t That Special?”), but a real powerful PostScript programming tool.
Lasertalk provides just about everything a PostScript programmer could want, and it does it simply and ingeniously. Upon start-up, it establishes interactive contact with the PostScript Executive or interpreter resident in a PostScript printer (such as the LaserWriter) via AppleTalk. Users can then “converse” with the printer directly — examining PostScript stacks, dictionaries, and the current status of the printer; as well as downloading files in batch mode or line by line. Although Lasertalk can be used off-line and includes a first-rate text editor, to take advantage of all its features, you should be connected to a running printer.
Lasertalk’s initial window is the interactive window (accessible only when you’re on-line with a PostScript printer). Here you’ll be met with information about the version of PostScript ensconced in your printer and the prompt PS>, where you can begin to enter PostScript code. Code typed in here is immediately sent to the printer, and you receive feedback from the PostScript Executive as to errors, if any.
The Status window reviews the current state of your printer and various aspects of the PostScript environment such as line width, current-point, gray level — in fact, just about anything you want it to, since you can easily customize the Status window during any work session.
The Edit window is where you enter PostScript code (or open a PostScript program generated by another application such as Adobe Illustrator) for examination and remarkably easy debugging. A file placed here can be downloaded in its entirety while on-line, “stepped through” line by line, or even downloaded in parts by establishing “break points” in the file where Lasertalk stops the download until you tell it to continue. During all this, you constantly receive updates via the Status window or by on-screen alerts that inform you of problems and PostScript errors. The Status window also provides an excellent way to learn and understand PostScript, since you can view how each line or block of your input affects the order of stacks within the PostScript interpreter.
Good Search, Find, and Replace features are accessible from menus and the keyboard. You can select individual words, whether “keys,” operators, etc., in any window and then search for them in the PostScript dictionaries and stacks by using the Dictionary Browser or by pressing COMMAND-L (for “lookup”). Lasertalk then searches for the selected item throughout all PostScript stacks and displays the definition. You can also select words within a definition and look them up. By choosing documentation search from the Search menu, you can view the relevant material from Addison-Wesley’s PostScript Language Reference Manual for any selected word. It’s the best on-line help imaginable for PostScript programming.
Lasertalk really shines once a program is ready to run. Unlike Post-Haste, the only other program out there for serious PostScript programming, Lasertalk lets you preview your output on-screen before printing. It does this by reproducing the contents of the raster memory of your printer at a 4-to-1 ratio that guarantees an excellent image on the screen, albeit at four times the size of the original. The software provides some quick-and-easy two-digit commands that you can type in the Interactive window to reduce the image so that you can see more of the page. The Preview window has rulers at the top and left side of the screen that give you the proper PostScript x and y coordinates of the portion of the page in the window at any one time.
The manual, although plagued by “printer’s goblins,” is excellent (it’s written by David Holzgang, author of Understanding PostScript), The two-disk set includes a considerable amount of PostScript artwork and Cookbook examples from Addison-Wesley.
Wasson, Gregory. (May 1988). Lasertalk. MacUser. (pgs. 102, 104).
Randy Adams
Applications
out of 10 (0 vote)
13 / 
2021-12-05 / 
a104270d5df15a97ef0e40bbe178c86538b2e2cc / 
/ 
Lasertalk.zip
Emulating this? It could probably run under: 
Mini vMac
