INMC 80 News

  

October–December 1981, Issue 5











Page 50 of 71











BLS PASCAL

BLUE LABEL SOFTWARE PASCAL

a review by Rory O’Farrell

This is one of the most interesting Pascals which has recently become available for the Nascom. It is available on tape (1200 Baud, to run under Nas-Sys) living at 1000H, or in EPROM, 6x2716s living at 0D000H. Distribution is through Electrovalue Ltd., and I understand that it will be available through other Nascom dealers. I only have approximate costs. These are, for the tape 50.00, and for the EPROMS 90.00.

The tape is recorded at 1200 baud CUTS, and loaded first attempt, with no errors, as it should. (As the interface on the N2 is the Cottis Blandford, there is no reason why you shouldn’t be able to record and read reliably at 1200 baud. If not, try adjusting VR1 again!)

The tape loads from 1000H to 4000H. The package is entered by E2180 XXXX, where XXXX is the highest address to be used. If the XXXX is omitted, then all available RAM is used. (If you have a 64k system, watch out! The address it will set as the highest is 0000, and you will get memory full messages! Re-enter the package using FFFF as the limit address). You get a commercial, and then a ‘>’ prompt for a command.

The operating system recognises 11 commands, which can be divided into four groups:

1. Loading and saving text to/from tape
2. The Editor
3. The compiler
4. Miscellaneous commands

It is probably best to deal with these in order. The Load and Save allow a named program to be loaded/​saved. There is also a Verify command, to check for a good save.

The Editor is a very remarkable piece of work. It allows 80 character lines, and the VDU appears as a window on these lines. This window can be moved up and down or right and left. If you go off on the right, suddenly you come around on the text on the left. There are 27 commands in the Editor, which are obtained either by the dedicated keys for cursor movement, or by depressing the cursor around, insertion/​deletion of block move characters, movement of marrked blocks, tabulation, searching for named strings, and return to main command loop of the compiler. There is one other one which the world has been waiting for. This is CTRL/G, which turns the Graphics key into an ALPHA LOCK key. Each time the Graphics key is pressed when this command is in use, the keyboard changes from lower to upper case, or upper to lower, as appropriate. It is also possible to allow the Graphics key to behave as normal.

The best way to describe the editor is to say that it is not unlike the NASPEN editor. There are no line numbers, and you can move about the text, inserting and deleting as the fancy takes you. It takes a little bit of getting used to, but as it allows 80 char. lines, it is a much nicer editor for programming than a line oriented editor which will only allow 48 chars.

Having entered the source program, one exits the Editor by a CTRL X, and returns to the command mode of the operating system. After saving the program on tape, using the named Save facility, one can proceed to try a Compile. If in compiling any error is found, compilation is halted, and you are returned to the Editor, with the screen set to the line in error. You are prompted by a message on the top line of the screen to “Hit Space”, and this done, you lapse into the edit mode, to make whatever corrections you think necessary.












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