80-Bus News


November–December 1983 · Volume 2 · Issue 6

Page 13 of 67

Both tape and EPROM versions of NASPAS are supplied with two booklets, a programming manual and an operating manual. The operating manual contains information on getting the system going and details on running the editor, the compiler and other miscellaneous information. The details in both manuals are quite sufficient and well written, but the programming manual, whilst accurate, is rather formal and could be rather heavy going for a novice to Pascal. The programming manual describes the format of Pascal, including data types, declaration expressions, statements, procedures, functions, parameters, etc, all very carefully. But I found the lack of examples made it somewhat difficult to define problems and sort out syntax errors when I got going. A good book on Pascal programming would seem to be a great help as well as the information supplied.

The tape version was supplied on a high quality cassette and loaded easily at 1200 BAUD. The EPROM version is supplied as six 2716 and runs from D000H to FFFFH, and is started in the same way as the Nascom Basic, that is, typing ‘J’ for cold start, plus the memory space to be allocated, otherwise NASPAS defaults to all available memory allocated. ‘Z’ warm starts NASPAS.

I had some difficulty with the EPROM version, as the title on the screen and the keyboard input routines appeared to be corrupt. As a listing is not supplied, I was unable to check the code myself, so the chips were returned, only to be sent back with ‘no fault found’. As the fault was still apparent, I resorted to checksumming the EPROMS and found that one would occasionally give a different result. I made a copy of the chip to tape, and then erased and reblew the EPROM. After that my troubles disappeared. The fault seeming to be poor programming of the chip in question.

A good selection of functions are available including trig. functions, string functions, some graphics functions and port I/O. Also external machine code routines can be called, and external printer patches are provided to allow listings to be made from the editor.

In use, programs are written with the NASPAS editor which uses screen editing facilites similar to NAS-SYS with the exception that a line may be up to 80 characters long, the text scrolling sideways to the left off the screen as text is added to the right. When first used, the effect can be a little disconcerting. Editing of lines which ‘wrap round’ the screen can also be achieved by moving the cursor to the correct position on the screen, editing, and then pressing the ENTER key.

Once a program is written, it may be compiled and the error codes are displayed one at a time on the top line of the screen with the cursor pointing to the approximate place of error within the text. The meanings of the error codes are listed in the back of the manual. When a successful compile is achieved, then a message is displayed giving the memory locations of the source code, and the also of the machine code program produced.

Both the source code and the machine code produced can be loaded to and from tape, with or without file names. The machine code program produced can be reloaded and run ‘stand alone’ so long as the run-time program in NASPAS is present at the same time.

It appears to be very versatile and very fast. A comparison drawn with Nascom Basic indicates truly remarkable speed, and programs containing masses of ‘IF’ statements and the like cause no problems at all. Most of my programs are written for amateur RTTY operation and in the past have been mostly machine code; the Pascal versions appear to run with almost machine code speed.

Overall NASPAS appears to be a very versatile package as supplied, and is an excellent addition and alternative to the Nascom ROM Basic.”

Page 13 of 67