PRINT‰ – This commences a print at the specified point and has been included, so the
manual says, for easier conversion of TRS 80 programs to NASCOM’s. Without the ‘‰’
PRINT acts as normal.
PUT – Arguments which are numbers are printed as their equivalent ASCII characters and
strings are printed as messages.
WRAP – This is yet another gem!! When enabled by a ‘+’ it prevents word wrap round
i.e. stops a word being printed half at the end of one line and the other half at the
beginning of the next. In conjunction with the EDIT command it makes text handling a
real doddle!! To disable it the argument is ‘-’.
VDU – This prints strings and evaluates string expressions and prints them at the
coordinates specified as per ordinary SCREEN coordinates. The top line can be written
IF..THEN..ELSE – Speaks for itself.
REPEAT..UNTIL – Loop until condition is true.
WHILE..WEND – If the condition is true then loop. These commands give truely
structured programming in BASIC, and they are VERY easy to use. You don’t need to know
BREAK – This enables or disables the break action of the ENTER key. So what!!
COPY – This is very similar to the C command of NAS SYS except the arguments are in
decimal. It is possible to over write your program!! It might be useful for fast
action graphics games.
DELAY – The argument ‘n’ causes a delay of nmsec.
SET – Already explained.
SPEED – This allows control of the repeat keyboard speeds. The first argument delays
the start of the repeat and the second argument is the interval between repeats.
You might have gathered by now that I’m rather impressed with XBASIC and blind
to its faults. It does in fact have a few bad points :
There is no APPEND which I think is a major ommission. The manual explains how
it can be done by saving a listing to cassette, which is almost an admission of the
The starting up of XBASIC is a real bind. The manual indicates that the ROM
version of XBASIC does all the initialisation for you. It should be quite easy to
modify the tape version to do this too.
The manual is very clear and the appendicies are very helpful, but I would
have liked an assembly listing of XBASIC, the extra fee would have been well worth it.
Despite there being some extremely useful new commands there are in my opinion
some unnecessary ones viz BREAK,XREF or XLIST (they do almost the same thing), CHECK
(RENUMBER does this any way) and PRINTS, PUT and VDU are nice but a bit extravagant.
I’ve already mentioned I would have liked an APPEND, but another command I would have
really liked to see is ‘FIND string and REPLACE with’. I KNOW how useful this would be
but I’ve never seen it mentioned anywhere. Is it really that difficult to do? Well
I’ll soon find out when I start to attempt adding (and replacing?) commands to XBASIC.
The demo program is a bit simple.
CONCLUSION : XBASIC is exceptionally good value for money. The extra commands it gives
to ROM BASIC are on the whole very useful, lucidly explained in the manual and easy to
use. Further, it is possible to add your own commands to produce a very personal
BASIC. XBASIC is available from Level 9 Computing, ___ _________ ____, High Wycombe,
Bucks., on tape price £15.00 or in ROM price £25.00.