I need some advice on programming please(many Q's)
The Doctor
I want to learn a prgramming language, but I'm not sure which one to
learn.
My only previous experience of programming is what I learnt of BBC basic
10-11 years ago.
Even with this, I only mastered the basics. Things like the DIM and
DEF_FN commands eluded me (and lots more besides!) and as there was
no-one to ask, I more or less gave up.
It would be nice to take a college course to learn this as I find I now
have lots of time on my hands.
My HTML lecturer suggested I learn Visual Basic to begin with.
Now I know thisis a Micro$oft thingy and thus probably nowhere near as
versatile as ARM BASIC,but at least at college there is someone to ask
if I get stuck (and I'm sure I will!).
The thing is, is what I learn likely to be of any use to me when
programming in ARM BASIC?
Or should I learn something else completely like C+ (or is it C++?),
bearing in mind that I know absolutely nothing about this language?
I can probably do a course on this too, but it will of course be done on
Windows machinery:-(
This is probably not just a passing faze, as I've been pondering the
situation for some weeks now and not made any decision, hence this post.
What should I do?
Cheers!
--
The Doctor
Vincent Lefevre
The Doctor <thed...@thedeathzone.free-online.co.uk> wrote:
> My HTML lecturer suggested I learn Visual Basic to begin with.
He's completely crazy!!!!!!!!!!
Here are 3 languages you can find on RISC OS and other platforms:
I would say Perl. This is a nice language, that allows to do a lot of
things efficiently.
Now, if you want a low-level language, you can try C.
Another suggestion... It seems that Lua is a good language, though
I don't know it yet...
--
Vincent Lefèvre <vin...@vinc17.org> - Web: <http://www.vinc17.org/> - 100%
validated HTML - Acorn Risc PC, Yellow Pig 17, Championnat International des
Jeux Mathématiques et Logiques, TETRHEX, etc.
Work: CR INRIA - computer arithmetic / PolKA research team at LORIA
Rob Kendrick
Vincent Lefevre <vincen...@vinc17.org> wrote:
<snip>
> Another suggestion... It seems that Lua is a good language, though
> I don't know it yet...
Learn it at once. Its lovely.
Cheers,
--
Rob Kendrick, http://www.digital-scurf.org/
Life is as tedious as a twice-told tale Vexing the dull ear of a drowsy man.
Vincent Lefevre
Rob Kendrick <r...@digital-scurf.org> wrote:
> In message <4a243e945ev...@vinc17.org>
> Vincent Lefevre <vincen...@vinc17.org> wrote:
> <snip>
> > Another suggestion... It seems that Lua is a good language, though
> > I don't know it yet...
> Learn it at once. Its lovely.
Well, I'm rather busy until Friday, but I was speaking about it mainly
because I'm going to learn it, now that I know it has been ported to
EPOC...
Rob Kendrick
Vincent Lefevre <vincen...@vinc17.org> wrote:
> In article <52ab4a2...@digital-scurf.org>,
> Rob Kendrick <r...@digital-scurf.org> wrote:
> > In message <4a243e945ev...@vinc17.org>
> > Vincent Lefevre <vincen...@vinc17.org> wrote:
>
> > <snip>
>
> > > Another suggestion... It seems that Lua is a good language, though
> > > I don't know it yet...
>
> > Learn it at once. Its lovely.
>
> Well, I'm rather busy until Friday, but I was speaking about it mainly
> because I'm going to learn it, now that I know it has been ported to
> EPOC...
And RISC OS. It doesn't really take any effort to port; it compiles
unmodified on pretty much everything. I've got a nice distrib of Lua 4.00
Final for RISC OS here, that includes libraries for linking, stand-alone
runtime, help etc... If anybody's interested; I'll upload it somewhere.
Cheers,
--
Rob Kendrick, http://www.digital-scurf.org/
Happy is the man with a wife to tell him what to do and a secretary to do it.
Stefan Bellon
Rob Kendrick <r...@digital-scurf.org> wrote:
[snip]
> I've got a nice distrib of Lua 4.00 Final for RISC OS here, that
> includes libraries for linking, stand-alone runtime, help etc... If
> anybody's interested; I'll upload it somewhere.
Don't we already have Lua 4.0? At least I have it sitting here on my
hard disc. Author is G.C. Wraith according to the help file.
Greetings,
Stefan.
--
Stefan Bellon * <mailto:sbe...@sbellon.de> * <http://www.sbellon.de/>
VirusScan Message: Windows 3.1 found: Remove it? (Y/n)
Vincent Lefevre
[Lua]
> And RISC OS. It doesn't really take any effort to port; it compiles
> unmodified on pretty much everything. I've got a nice distrib of Lua 4.00
> Final for RISC OS here, that includes libraries for linking, stand-alone
> runtime, help etc... If anybody's interested; I'll upload it somewhere.
Yes, I'm interested.
BTW, can you do system calls, use the Wimp, etc?
Rob Kendrick
Stefan Bellon <sbe...@sbellon.de> wrote:
> In article <f50e7b2...@digital-scurf.org>,
> Rob Kendrick <r...@digital-scurf.org> wrote:
>
> [snip]
>
> > I've got a nice distrib of Lua 4.00 Final for RISC OS here, that
> > includes libraries for linking, stand-alone runtime, help etc... If
> > anybody's interested; I'll upload it somewhere.
>
> Don't we already have Lua 4.0? At least I have it sitting here on my
> hard disc. Author is G.C. Wraith according to the help file.
Yes, the difference is that his port is designed for writing programs in,
where mine isn't (although it can be used as such.) The last time I looked,
his was also Lua 4.00 Alpha or Beta, nor final. There are a lot of
differences between all three,
Cheers,
--
Rob Kendrick, http://www.digital-scurf.org/
Better to idle well than work badly.
Rob Kendrick
Vincent Lefevre <vincen...@vinc17.org> wrote:
> In article <f50e7b2...@digital-scurf.org>,
> Rob Kendrick <r...@digital-scurf.org> wrote:
>
> [Lua]
> > And RISC OS. It doesn't really take any effort to port; it compiles
> > unmodified on pretty much everything. I've got a nice distrib of Lua
> > 4.00 Final for RISC OS here, that includes libraries for linking,
> > stand-alone runtime, help etc... If anybody's interested; I'll upload it
> > somewhere.
>
> Yes, I'm interested.
>
> BTW, can you do system calls, use the Wimp, etc?
That's not what its really designed for, nor is it able to cope with most
of the data types that SWIs return. (For example, there is no real concept
of a 'pointer').
Easy to add though.
Cheers,
--
Rob Kendrick, http://www.digital-scurf.org/
Hard work has never killed anyone, but it frightens some people half to death
Rob Kendrick
> In article <f50e7b2...@digital-scurf.org>,
> Rob Kendrick <r...@digital-scurf.org> wrote:
>
> [Lua]
> > And RISC OS. It doesn't really take any effort to port; it compiles
> > unmodified on pretty much everything. I've got a nice distrib of Lua 4.00
> > Final for RISC OS here, that includes libraries for linking, stand-alone
> > runtime, help etc... If anybody's interested; I'll upload it somewhere.
>
> Yes, I'm interested.
I'll tidy it up and pop an announcement on csa.a :)
--
Rob Kendrick, http://www.digital-scurf.org/
Life is a tragedy when seen in close-up, but a comedy in long-shot.
Andrew Hill
> > hard disc. Author is G.C. Wraith according to the help file.
>
> Yes, the difference is that his port is designed for writing programs in,
> where mine isn't (although it can be used as such.) The last time I
looked,
> his was also Lua 4.00 Alpha or Beta, nor final. There are a lot of
> differences between all three,
<scatches head> You have a programming language that you don't write
programs with? What do you do with it? I'm confused, but would love an
explanation.
I read a little of LUA, thought it looked nice, but heard nothing on the NGs
or whatever suggesting it was any good, so haven't learnt it yet. I think I
ought to :o).
Maybe I will now. I'm just getting used to using JFPatch to write in
assembler with - v. nice Justin :o), FAR better than just using BASIC.
ATB
Andrew
David Boddie
> > > Don't we already have Lua 4.0? At least I have it sitting here on my
> > > hard disc. Author is G.C. Wraith according to the help file.
> >
> > Yes, the difference is that his port is designed for writing programs in,
> > where mine isn't (although it can be used as such.) The last time I
> looked,
> > his was also Lua 4.00 Alpha or Beta, nor final. There are a lot of
> > differences between all three,
>
> <scatches head> You have a programming language that you don't write
> programs with? What do you do with it? I'm confused, but would love an
> explanation.
Presumably, he means that it wasn't designed to be used interactively, in
a taskwindow or at the command line.
> I read a little of LUA, thought it looked nice, but heard nothing on the NGs
> or whatever suggesting it was any good, so haven't learnt it yet. I think I
> ought to :o).
Or you could look at Python
Laurence Tratt ported version 1.5.2 for RISC OS
http://www.eh.org/~laurie/comp/acorn/ropython/index.html
and Dietmar Schwertberger ported version 2.0
There's also a version 1.6 available for those who like a choice in
software licenses!
I find the libraries that are packaged with Python really very
useful. Especially the network/Internet related ones.
--
David Boddie
Solar MHD Theory Group, St Andrews
http://www-solar.mcs.st-and.ac.uk/~davidb/index2.html
Rob Kendrick
David Boddie <dav...@mcs.st-and.ac.uk> wrote:
> On Fri, 1 Dec 2000, Andrew Hill wrote:
>
> > > > Don't we already have Lua 4.0? At least I have it sitting here on my
> > > > hard disc. Author is G.C. Wraith according to the help file.
> > >
> > > Yes, the difference is that his port is designed for writing programs
> > > in, where mine isn't (although it can be used as such.) The last time
> > > I
> > looked,
> > > his was also Lua 4.00 Alpha or Beta, nor final. There are a lot of
> > > differences between all three,
> >
> > <scatches head> You have a programming language that you don't write
> > programs with? What do you do with it? I'm confused, but would love an
> > explanation.
>
> Presumably, he means that it wasn't designed to be used interactively, in a
> taskwindow or at the command line.
No, I mean its not designed for writing programs in. Lua was designed as
an embedded scripting language (although it can be used as a standalone
language)
> > I read a little of LUA, thought it looked nice, but heard nothing on the
> > NGs or whatever suggesting it was any good, so haven't learnt it yet. I
> > think I ought to :o).
>
> Or you could look at Python
>
> http://www.python.org/
Yes, but Python is very large, slow and difficult to learn (compaired to
Lua, anyway)
Cheers,
--
Rob Kendrick, http://www.digital-scurf.org/
His sole concern with work was considering how he might best avoid it.
Vincent Lefevre
Rob Kendrick <r...@digital-scurf.org> wrote:
> No, I mean its not designed for writing programs in. Lua was designed as
> an embedded scripting language (although it can be used as a standalone
> language)
But is it possible to use Lua as a scripting language for a generic
graphical program?
The Doctor
Lets see, Perl, Lua, Python, ML, Awk,
I'd never even heard of these until now.
Are they widely used?
Are any professional programs programmed in these languages?
>> My HTML lecturer suggested I learn Visual Basic to begin with.
>He's completely crazy!!!!!!!!!!
Why? Because BASIC is not a good language to learn? Or because Visual
Basic bears no resemblance to BBC BASIC?
AFAIK, most Colleges (certainly Havering Tech) use PC's, so a class in
BBC Basic is not going to happen. (Unless anyone knows different?)
Any more thoughts?
--
Graham
Vincent Lefevre
The Doctor <thed...@thedeathzone.free-online.co.uk> wrote:
> Lets see, Perl, Lua, Python, ML, Awk,
> I'd never even heard of these until now.
> Are they widely used?
> Are any professional programs programmed in these languages?
If you want a very widely used language with "professional" programs
programmed in, then you should learn COBOL! :)
Now, Perl, Lua, Python, ML, Awk are quite widely used, but AFAIK,
they're aren't used for stand-alone programs. Perl is very useful
to work on text, and has interesting security features; thus it is
the recommended language for CGIs, for instance. And it can be
found on many platforms. Lua may be the most portable one.
I wouldn't recommend Awk (mainly used in some shell scripts under
Unix), as it can be entirely and more efficiently replaced by Perl.
>>> My HTML lecturer suggested I learn Visual Basic to begin with.
>>He's completely crazy!!!!!!!!!!
> Why? Because BASIC is not a good language to learn? Or because Visual
> Basic bears no resemblance to BBC BASIC?
Because BASIC isn't a good language, and in particular, Visual BASIC
is very proprietary. Well, unless you want to program under windoze
only...
Alex Waugh
> In article <cd4f1c2...@digital-scurf.org>,
> Rob Kendrick <r...@digital-scurf.org> wrote:
>
> > No, I mean its not designed for writing programs in. Lua was designed as
> > an embedded scripting language (although it can be used as a standalone
> > language)
>
> But is it possible to use Lua as a scripting language for a generic
> graphical program?
Its not generic, but Roots uses Lua as a scripting language
http://www.ecs.soton.ac.uk/~ajw498/genealogy/
Alex
--
Alex Waugh Electronics student ajw...@ecs.soton.ac.uk
RISC OS freeware at http://www.ecs.soton.ac.uk/~ajw498/
Michael Rozdoba
The Doctor <thed...@thedeathzone.free-online.co.uk> wrote:
> BBC Basic is not going to happen.
Why not?
See:
> I would like to announce the release of the first version of my
> portable BBC Basic interpreter, Brandy. It runs under RISC OS,
> NetBSD, Linux, DOS and Windows. The program can be downloaded
> from my web site at:
> http://www.argonet.co.uk/users/dave_daniels
So they have no excuse (not that I'm recommending BASIC over alternatives
- only that if it must be BASIC it can be the one true BASIC).
--
_ _
Michael Rozdoba ICQ: 15835336 |_| |_ | |_| i'm trapped | | |
Ashamed to belong to a club called ACNE | | |_ |_ | in reality ... o o o
mroz at ukgateway dot net // ......... homepage coming soon .........
David Boddie
> In message <Pine.LNX.4.21.00120...@localhost.localdomain>
> David Boddie <dav...@mcs.st-and.ac.uk> wrote:
...
> > Or you could look at Python
> >
> > http://www.python.org/
>
> Yes, but Python is very large, slow and difficult to learn (compaired to
> Lua, anyway)
Perhaps, when compared to Lua.
I find Python really useful and, although it has some interesting and
unexpected features for users already familiar with other languages, I
would imagine that it would be fairly suitable for a first programming
language - which is what was being discussed originally.
Feel free to argue, anyway. That's what I'm here for!
Paul Boddie
>
> Now, Perl, Lua, Python, ML, Awk are quite widely used, but AFAIK,
> they're aren't used for stand-alone programs. Perl is very useful
> to work on text, and has interesting security features; thus it is
> the recommended language for CGIs, for instance. And it can be
> found on many platforms. Lua may be the most portable one.
> I wouldn't recommend Awk (mainly used in some shell scripts under
> Unix), as it can be entirely and more efficiently replaced by Perl.
I would ask you to qualify your use of "stand-alone", but I do know what you
mean - distributing "scripting language" programs as single file executables can
be more complicated than envisaged, but it is possible. However, the
availability of language runtimes for different operating systems, where some of
those operating systems are even being shipped with Python and Perl (for
example), means that such executable distribution may be unnecessary. Lots of
Linux distributions ship with Python these days, for example.
It's contentious to write that Perl is "the recommended language for CGIs", but
then are CGIs "where it's at" for Web application development? Certainly, Perl
has some interesting features, such as data tainting, but I would rather design
my applications properly and be aware of the security issues.
> Because BASIC isn't a good language, and in particular, Visual BASIC
> is very proprietary. Well, unless you want to program under windoze
> only...
I would agree. Why on Earth anyone would want to write in BBC BASIC in
preference to more modern languages these days is a mystery to me.
Regards,
Paul
Vincent Lefevre
Paul Boddie <pa...@infercor.no> wrote:
> I would ask you to qualify your use of "stand-alone", but I do know what
I meant in fact both single file executables and programs that are
started by the user (i.e. not used by other programs).
> you mean - distributing "scripting language" programs as single file
> executables can be more complicated than envisaged, but it is possible.
> However, the availability of language runtimes for different operating
> systems, where some of those operating systems are even being shipped with
> Python and Perl (for example), means that such executable distribution may
> be unnecessary.
The problem with Perl is that it has still bugs (in particular,
concerning signals). So, the version installed on the system is
not always the one I should use. Moreover, I need to use different
architectures (which is a problem for the #! line, because the
executables are not at the same place)...
> It's contentious to write that Perl is "the recommended language for CGIs",
> but then are CGIs "where it's at" for Web application development?
> Certainly, Perl has some interesting features, such as data tainting, but I
> would rather design my applications properly and be aware of the security
> issues.
Yes, but being helped by the language and/or the compiler (with
compilation warnings, for instance) is a good point.
Paul Boddie
>
> In article <3A3E4C4F...@infercor.no>,
> Paul Boddie <pa...@infercor.no> wrote:
>
> > I would ask you to qualify your use of "stand-alone", but I do know
>
> started by the user (i.e. not used by other programs).
For Python, at least, there's freeze and another installer tool. Some of the
commercial IDEs might support packaging in similar ways.
> > However, the availability of language runtimes for different operating
> > systems, where some of those operating systems are even being shipped
> > with Python and Perl (for example), means that such executable
> > distribution may be unnecessary.
>
> The problem with Perl is that it has still bugs (in particular,
> concerning signals). So, the version installed on the system is
> not always the one I should use. Moreover, I need to use different
> architectures (which is a problem for the #! line, because the
> executables are not at the same place)...
Can you not use #!/usr/bin/env ... as your first line, at least on UNIX
variants?
> > It's contentious to write that Perl is "the recommended language for
> > CGIs", but then are CGIs "where it's at" for Web application
> > development? Certainly, Perl has some interesting features, such as
> > data tainting, but I would rather design my applications properly and
> > be aware of the security issues.
>
> Yes, but being helped by the language and/or the compiler (with
> compilation warnings, for instance) is a good point.
I was browsing through an interesting book on security the other day which went
to respectable lengths to describe the problems with handling user input. Of
course it's nice to have some support from the tool, but there are so many
security issues to get to grips with in Web programming that it's almost
frightening. ;-)
Regards,
Paul
Vincent Lefevre
Paul Boddie <pa...@infercor.no> wrote:
> > The problem with Perl is that it has still bugs (in particular,
> > concerning signals). So, the version installed on the system is
> > not always the one I should use. Moreover, I need to use different
> > architectures (which is a problem for the #! line, because the
> > executables are not at the same place)...
> Can you not use #!/usr/bin/env ... as your first line, at least on UNIX
> variants?
This is what I sometimes use, but there are several problems. For
instance, the program name no longer appears in "top". And the -T
option isn't taken into account (I had to write a perl-T script
that runs Perl with the -T option).
Vincent Lefevre
Jonathan Graham Harston <j...@arcade.demon.co.uk> wrote:
> Subject: Subject: Re: I need some advice on programming please (many
> Organization: Arcade - The Definitive Acorn BBS
> X-Mailer: ArcadeLink - Email/News Gateway
> X-System: ArcadeLink
Oh no! :((( The Arcade email to news gateway is still broken. :(
Andrew Hill
----- Original Message -----
From: "Jonathan Graham Harston" <j...@arcade.demon.co.uk>
Newsgroups: comp.sys.acorn.programmer
Sent: Monday, December 25, 2000 3:48 PM
Subject: Subject: Re: I need some advice on programming please (many
> pa...@infercor.no wrote:
> > > Because BASIC isn't a good language, and in particular, Visual BASIC
> > > is very proprietary. Well, unless you want to program under windoze
> > > only...
> > I would agree. Why on Earth anyone would want to write in BBC BASIC in
> > preference to more modern languages these days is a mystery to me.
>
> But I would certainly prefer BBCBasic in preference to more primative
> languages, such as QBasic, VisualBasic, et al.
Depends. I'm going to stick my neck out and point out that in some ways
VB/VBA is much nicer than BASIC V. Code management, for example, is IMHO
(purely IMHO you understand,) much better, and the syntax can be clearer if
you're careful with it. I think this is moreso than BASIC V which is too
flexible. I prefer for example, the object model scenario to the SWI
interface. However, it's mainly the syntactics and UI of it rather than the
content, for which I prefer BASIC V. Since BASIC V hasn't really been
updated much for 13 years, that doesn't surprise me either...
I must also point out that much COULD be done with VBA. If the object
modelling was actually seamless, programming new classes for it would be
nice. As it is, it isn't, but is the nicest way that you can write a library
with it. My personal tactic is to build a 'parent' class called the
application's name with App on the end, eg 'AtlantisApp', which interfaces
with the main opening window and initialises a copy of all the other 'main'
classes so that it's more seamless. Making enumerated lists is impossible on
anything other than Office 2000 and (I think,) VB 6, and since I'm not
allowed to use anything other than Office '97 and VB 5, that's a problem.
Also bad are things like being able to make Excel die horribly easily. For
example, try opening the Visual Basic Editor in Excel '97 and typing :
Cells(1, 0).FormulaR1C1 = "Hello World!"
Hmm...Why did your machine do that? Why not a simple 'invalid cell
reference' error... Particularly since, eg 2 :
For i = 20 To 0 Step -1
Cells(1, i).FormulaR1C1 = "Hello World!"
Next
will cause the same problem. Now think of an example where you didn't
realise i could equal 0...Great fun when Excel keeps dying because of some
dumb logic error...
Oh, for a combination of the good bits of VBA/VB with typical Acorn user
friendliness and flexibility. What could be made of it...</dream
sequence>...
[ducks enraged posters screaming because I said VB was nice]...
Oh yeah. In my defence I also get paid to play with VB, whereas BASIC V I do
for fun, so I guess VB does have rose-tinted specs. there too :o).
Incidentally, is there much demand for a program to synchronise !Organizer
files with Outlook? I could write one, but I don't know how popular it would
be. I haven't played with Outlook's API (or Outlook that much,) so I'm
interested in doing something like that as an experiment, mainly through
boredom of playing with Excel, Word and Access so much...
ATB
Andrew
Dave Daniels
Andrew Hill <Andre...@cryogen.com> wrote:
> content, for which I prefer BASIC V. Since BASIC V hasn't really been
> updated much for 13 years, that doesn't surprise me either...
The Acorn interpreter might not have been updated much, but there
is also my BBC Basic interpreter, Brandy. This runs under a
variety of operating systems such as RISC OS, NetBSD, Linux, DOS
and Windows. I have added a few extensions to Basic V that I think
are useful such as increasing the maximum length of strings and
allowing libraries to have their own local variables. The program
comes with source so in theory you can change and extend BBC Basic
to meet your requirements. You can download Brandy from
http://www.brandy.riscos.org.uk
I will be putting an updated version on the web site in the next
week or so.
Dave Daniels
Dave Higton
Vincent Lefevre <vincen...@vinc17.org> wrote:
> In article <001225...@arcade.demon.co.uk>,
> Jonathan Graham Harston <j...@arcade.demon.co.uk> wrote:
>
> > Subject: Subject: Re: I need some advice on programming please (many
> > Organization: Arcade - The Definitive Acorn BBS
> > X-Mailer: ArcadeLink - Email/News Gateway
> > X-System: ArcadeLink
>
> Oh no! :((( The Arcade email to news gateway is still broken. :(
I suspect it isn't broken; rather that JGH has forgotten how to
compose the Subject lines. I used to forget, too, when I used it.
The human problem is that there are two very similar message
formats, one for BBS messages, one for news via the the email-news
gateway. They differ in what you have to do on the Subject line.
JGH has just used the wrong one.
Dave
Dave Daniels
Richard Murray <no....@heyrick.co.uk> wrote:
I will have to answer this here as there is no valid email address
in the original.
> I am running Brandy 1.05 (DJGPP) which I downloaded from Arcade BBS (on a
> whim, really) on a 486DX/2 66MHz, 16Mb, genuine IBM PC.
> Loading it from the usual DOS boot up, sound card, HIMEM.SYS and the rest of
> that rubbish, it fails to load with "no DPMI".
> If I load Win3.11 and File->Run it, it starts up okay.
> What, exactly, is it looking for? How would I get DPMI going from DOS, or is
> it something Windows provides?
DPMI is built in to Windows but it is not a part of MSDOS. Brandy
will run under MSDOS but needs another program that adds DPMI
support to DOS. There is one called something like CWSDPMI.EXE.
Have a look for it. If you cannot find a copy then I can dig
it out and email one to you.
By the way, I have not tried the program under Windows 3.1 or 3.11
so it is useful to know it works there too.
> Anyway, I pressed ESC to return to BASIC. Brandy hung up with:
> --8<--------
> Internal error
> SIGINT received
> --8<--------
> (or something very similar, there may have been a few numbers in there?)
> Would it be possible, if not already done, to abort the program and return
> you to Brandy, rather than reporting a user interrupt?
I have seen this one before. It is not an error that Brandy itself
produces. I think that it comes from the graphics library I use to
provide graphics support in the DOS version of the program but it
is intermittent. Pressing 'Esc' normally works as expected, that
is, the Basic program is halted, when running programs that use
graphics.
> Thank you.
>
Dave Daniels