APPEND – Followed by a filename will open the file for subsequent writing onto
the end of the current data in the file.
CLOSE – Followed by the appropriate string handler for a file will close the
file. Unlike the ROM BASIC routine handler within Nas-Dos, XBASIC allows any
number of files to be open at one time subject to memory limitations. Close by
itself will close all files that are open at that time.
The file handling within XBASIC is very easy to use. File handling in ROM
BASIC is, in my view, cumbersome, although it was reasonably straight forward
to store strings but numeric data was more of a pain. In XBASIC, file storage
and retrieval of strings and numeric data is made as simple as I think it can
be whilst still retaining versatility.
Apart from the previously mentioned bug in the AUTO command, there are at
the time of writing (July 1983) several known bugs in the Nas-Dos version of
XBASIC which I am told is being looked into by Nascom. The two most drastic
ones are:–1) ASC files cannot be saved to disk although they can be saved to
tape and 2) attempts to retrieve programs or data from tape proves fruitless.
Hopefully these will be corrected shortly.
I find that I now no longer use ROM BASIC because XBASIC does all that
ROM BASIC does and more. Certain commands are lacking which need to be added
as debugging aids;namely TRACE and FIND routines etc. No doubt these will
appear as XBASIC becomes more widely used. Failing that I will have to write
the routines myself! My first attempt at writing an OLD command to retrieve
NEWed programs resulted in disaster as I could only recover the first line!
All in all I find XBASIC to be a useful interpreter and one that any Nas-Dos
user should not be without if only for the added disk commands that make
file handling so much easier than in ROM BASIC.
RAM-A board, 32k RAM, 2716 conversion (no EPROMs). With INMC mods, but still
won’t work at 4MHz without waits (dunno why...) #45 ono. HS1N twin-drive
digital cassette system. As reviewed 80-BUS News Vol 1 iss. 4 With original
ROMs (2708s, assembled for #D000 and ports #F8 to #FF) or my enhanced OS
(2716 – assembled for #D000, and ports #78 to #7F); 4118s, connecting leads
and some tapes. #170 ono Adrian Perkins Tel. Bracknell (____) ______.
Gemini Galaxy 2 Computer System, as new. Complete with WordStar and
MailMerge. #1300 ono. Tel. Peter Forsyth, Chesham (____) ______.
Colour/Sound/RTC, etc, card (Holmes – R&EW) as advertised in Vol 3, Iss 1.
Also HENELEC GM805 Disk Controller card. Any reasonable offers considered.
Chris Bowden (____) ______ for details.