|★ APPLICATIONS ★ PROGRAMMATION ★ PDQ PASCAL|8000 Plus) ★|
|PDQ Pascal||Applications Programmation|
The immediate impression is that this is UCSD Pascal, a venerable implementation of the language (in slightly non standard form) popular in America for many years. The programs USCD produces need a ‘runtime module' to work - ie. if you wanted to sell a program you'd written, the users would need the runtime module on their disc to make it work. If you wanted to sell it with your program you'd have to negotiate a deal with the original suppliers. It's really halfway between a compiler and an interpreter.
The first thing to be discovered, and it isn't on the outside of the package, is that the system will only work with an 8512 or a 9512. This is because the whole lot is a single file occupying 300k on the disc.This is carrying integration a bit too far.
To get the system running it is necessary to type pdq pdq.vol, which opens the 300K library file and brings up a command line at the top of the screen. From this the editor can be selected and, apparently, a number of other facilities.
Not only must you use the editor provided but your files remain locked up in the giant library file. PDQ Pascal provides no way to export your files from the library file to a separate file usable by another editor; the system is totally self contained.
Getting Wirth and Wirth
Once a file is created and saved to the library file it can be run. The program will, after being given several more names, execute and then deposit you back at the first menu. Programs also remain locked into the library file system and apparently cannot be used apart from it. This means that the PDQ system can only really be used to learn the Pascal language, not to make any practical use of it.
This sequence of events, edit and run, requires a large number of keystrokes and an almost constant churning of the disc drive as the system accesses the library file for its resources. The process involves a great deal of waiting.
Putting the library file in drive M speeds things up a little and cuts down the wear on the drive but leaves no room on M: for anything else. Also you must remember to copy the library file back to disc. It is essential to take backups when working with PDQ Pascal as a library file maintains its own directory within itself and any corruption there makes the file unusable. This weakness is not mentioned in the manual.
The convention adopted by PDQ Pascal for the naming of files is guaranteed to confuse anyone new to CP/M. Up to fifteen characters are allowed, for example. very,long.title, is acceptable. Text files are always given the filetype .TEXT, which is of course one character longer than CP/M permits. The editor will not recognise a file without this type.
In its original form UCSD Pascal proved a reliable and popular compiler though it must be remembered that there was little competition when it first appeared.
Pecan say you can upgrade to UCSD Pascal ‘at a reasonable cost' - £119.54 inclusive of VAT Postage and packing less the cost of PDQ Pascal.
On the plus side it has to be said that for a complete beginner unused to anything else PDQ Pascal would provide a reasonable training ground. The system is quirky but usable and the manual leads you through the elements of Pascal in easy stages. You would still need another book on Pascal for comparison and detailed descriptions of function usage.
On the minus side there is the fact that you can't use any other Pascal code you might come across, since you are unable to read in and modify existing programs to use under this system. The editor is a dog (the PDQ editor that is) and PDQ Pascal abuses CP/M rather, making the system very slow and unwieldy. The PDQ system is incompatible with everything else you might use on your computer.