It was with considerable excitement that I loaded the cassette from Datron containing their new 12K integer Pascal package. Pascal has received much publicity as being superior to Basic, and while I feel that both languages have their advantages it would be marvellous to see Pascal running on a Nascom. The tape loaded with no difficulty, and I cold started the program.

Editor

The editor takes quite a lot of getting used to. When adding lines they don’t usually have line numbers. A command is entered to renumber all the lines before lines are listed or changed. Changing lines would be very tedious if you did not use the NAS-SYS version, since the NAS-SYS line editing can be used as in Basic. You can add, change or delete individual lines by line number. At this point I found my system sometimes “crashed”, forcing me to reload Pascal and start again. Eventually the problem was traced to the fact that entering a command when the file position is not at the end of file, instead of giving an error, crashes the system completely.

Compiler

The compiler is very fast indeed, and it operates in two passes. If there are any errors in the program these are detected in the first pass. The compiler stops after the first error, but it is so fast that this is not much of a disadvantage. The error messages just give an error number and display the line where the error was found. The actual error may be on the line before. If you don’t have a correct “END.”, at the end, some garbage is displayed but a correct message follows it.

Remember that only integers are supported, and this limits its usefulness for some applications. Character variables did not at first appear to be supported and the documentation does not mention them, but in fact they can easily be handled by treating them as arrays of integers. READ and WRITE statements support characters.

Statements supported are:

CALL is an extension allowing machine code routines to be called. MEM allows the equivalent of PEEK and POKE operations.

I then typed in the demonstration SORT program provided. This included the use of recursive calls and was impressively fast. When I came to save it on tape everything appeared all right, but when I later tried to read it in, disaster ! The Pascal did not allow sufficient delay at the end of the line for my tape speed of 2400 BAUD, and I could not reload the program. A speed of 1200 BAUD is, I am told, the maximum it will work with at present.

It is not possible to send program listings to your own printer routine, only directly to the UART.