a E i - Commodore Is Awesome

On The Blink
C
Drop a whatever you're doing and read
on.
i
l How many times have you been
developing i a large scale Basic program
n
and wished that there was an
easier way? Now there is because
g
Blinker-64 from Information Develop-
a
ment Systems has come to your rescue.
l Just what is Blinker-64? The
answer l is quite simple: Bunker-64 is a
linkage B editor for Basic programs. It
enables a programs to be constructed
from s a number of small modules
stored i as files on one or more disks.
c The main advantages to this
approach p to programming are firstly
that
r
small modules or subroutines are
easier o to handle, edit arid debug.
Secondly, g programming in Basic is
made more productive and enjoyable.
r
Modules developed for one program
a
can be saved as part of a library of
m
modules and used as component parts
of mothers
as easily as standard Basic
statements. e As your library grows, so
your r ability to produce larger and
more s complex programs increases.
! Basically, Blinker-64 allows the
programmer to make up a program of
subroutines, then knit them togther to
form a whole, The following example
should show this clearly.
Normal Basic Program
10 P0KE53280. 0:P0KE53281,0:
POKE646.2
15 GOSUB500
20 PRINT "NOW IS THE TIME ETC
ETC"
20 GOSUB600
30 PRINT "PRESS ANY KEY TO
CONTINUE"
40 GOSUB 700
50 END
500 P0KE53265, PEEK (53265) AND
239
510 RETURN
C64 REVIEW
Basic programmers take heart. This new software from
Information Development Systems should make life a lot
easier.
By Paul Eves
500 P0KE53265.PEEK (53265) OR 16
620 RETURN
700 WA1T198.1:POKE198,0
720 RETURN
As you can see, this program is
made up of a number of subroutines,
some may be called repeatedly, others
only once. Trying to keep track of all
these subroutines in a large program
can become tiresome. Moreover the
next time you write something else you
have to re-do all the subroutines again
which can become very monotonous.
With h Blinker-64 the above
program would look like this:
Blinker-64 Program
10 P0KE53280,0: P0KE53281,0:
PO K E646,2
20 GOSUB"SCREEN OFF"
30 PRINT "NOW IS THE TIME ETC
ETC"
40 GOSUB "SCREEN ON"
50 PR1Nr'PRESS ANY KEY TO
CONTINUE"
60 GOSUB "GET KEY"
70 END
The subroutines 'screen off',
'screen on' and 'get key' would be
individual files saved on your library
disk.
When Blinker-64 is invoked with
your blink command, it runs through
your BASE program (i.e. the one in
memory). Whenever it comes across a
GOSUB 'xxx', it fetches that
subroutine from your disk and
appends it at the end of your base
program. After all operations have
been done it renumbers the entire
program, substituting your named
subroutines for numbered ones.
The above fi les are known as
CODE files. One other use of Blinker-
64 is the handling of DATA files.
The principle is the same, with a
couple of exceptions. Data files can
only contain REM and DATA token
words. Any other token word would
YOUR COMMODORE january 1987
56
result in a fatal error.
There is a maximum of 255 distinct
module references that can be
appended in a single run_ Line number
values, previously considered important
when appending or merging Basic
programs, are now of little consequence.
Blinker-64 always produces a
correctly numbered program,
regardless of line numbers in any
constituency source module,
Whenever Blinker-64 finishes a
run, a summary screen is displayed
giving some simple statistics about the
linked program. The summary looks
like this:
1. Start of BASIC — Lower limit of
BASIC memory area
2. Start of VARIABLES — End address
of BASIC program
3. Top of BASIC — Upper limit of
BASIC memory area
4. CODE modules named — Number of
Code modules included, including
base mod.
5. CODE modules included — Number
of modules in linked program
6. DATA modules named — Number
of DATA modules specified on
command line
7. DATA Modules included —Number
of DATA modules included in linked
program
8, Bad Filenames — Number of illegal
module references encountered
9. Bad line numbers — Number of
illegal line numbers encountered.
There is so much more I could say
about the program, unfortunately
space is running out. All I need say is
that after trying this program out. I felt
that no Basic programmer should be
without it.
Touchline
Company: Information Development
Systems. Address: 24 Deerings Rd,
Reigate, Surrey. Tel; 07372 22755
Price: 129.90.