COMPUTER GAMMON - BUGS SOLVED?
Dear PAGE 6,
Having read Dave Hitchens' plea for help in 'Computer
Gammon – The Bugs', issue 29, I feel I may be able to shed some
light on the problem.
Looking at the sample VBI code, there was no sign of
a CLD instruction to set addition to binary mode. What was probably
happening was that Basic was changing this mode continually thus
causing inconsistent results from addition in the VBI code.
The solution to this is to save the processor status
register flags at the start of the VBI and restore them before
returning to Basic. You are then able to clear or set decimal mode
within the VBI, as you require, without affecting Basic.
The VBI code might read as follows:
PHP
;Save Flags to stack
CLD ;Set binary mode
:
: ; VBI code required.
:
PLP ;Restore Flags
JMP EXIT ;Return from VBI
I hope this is of use to Dave, and if he specifies
the problem with DLI's a little more precisely, I would be glad to
try and figure it out.
Keith Mayhew
Rayleigh, Essex
MORE FOR CASSETTE
Dear Sir,
In the Letters page of Issue 27 you asked: 'Is there
enough call for a cassette based version of Revision C?'.
There are still quite a number of us out here you know, who are
solely cassette based! And it is annoying to find that so many
listings are for disk only. Apart from the time factor, surely the
only real value of a disk drive is its search facility which is
rarely used on home machines.
I think that you should make a condition of
acceptance that any program should be capable of storing on both
disk and cassette. From the listings in your magazine it is obvious
that the contributors are experts in their field capable of
converting their program to both disk and cassette. Not so easy for
the poor cassette based beginner.
D.E.Fogerty
Salisbury, Wilt
Point taken. Wherever possible we try to ensure
that programs accepted for publication are suitable for both
cassette and disk but there are often cases
where excellent programs, such as The 3-D Animator in this issue,
are simply not suitable to run on cassette. This particular program
reads in other sections of the program from a menu as required and
also writes out individual files which are continually updated. This
might just be possible with tape but it would be so cumbersome that
I doubt whether anybody would actually be able to use the program
successfully! We would not exclude a program from publication
because it was written specifically for cassette and conversely feel
that we should publish good programs even if they are only suitable
for disk users. Don't be disappointed, you should find several
programs in each issue which will run on cassette and next issue
we'll put in that cassette based Revision C Basic!
SAME OLD STORY
Dear PAGE 6,
I have just returned home after three years abroad
and am disappointed, yet not really surprised, to find that the
plight of the 8-bit Atari User is as forlorn as it was when I left.
The absence of any software on the shelves of the high street shops,
even in London, is matched by the non-existent hardware. Sinclair,
Commodore, Amstrad, etc., are everywhere but no Atari, though there
is a smattering of ST's.
I tried to purchase a 1050 disk drive but was told,
as was being reported in the press, that stocks had been sold out
and a new double sided drive was expected soon at around £180. I
also read that with the introduction of the Mega Ataris the basic ST
is likely to be reduced in price whilst the XE is reportedly going
up in price.
It is clear that the XE is being overlooked yet again, presumably
because the ST range represents bigger profit margins. The 8-bit
market is basically mail order only where overheads are less,
therefore your reporting of the 'computer cowboys' is a valuable
service, and I would like to relate to my own 'mail order cowboy'
experiences.
Firstly, credit where it is due. I have found PAGE 6 to have the
best public relations department I have
experienced. Orders have been despatched promptly and queries always
answered. This is not true of certain other publications whose
organisation is appalling even if well meaning, or who do not bother
to respond at all.
The worst English company I have dealt with has been
'Cut Price Software', from Harlow, who have had my money for ten
months without responding to any of my letters. A solicitors letter
elicited a response that I had not responded to any of their letters
explaining the problems (I have
heard that excuse before), and a promise to return my money, which
they have not since done. I can accept that one letter may go astray
in the post but not every one! I am currently taking them to court,
however, they are no longer resident at their mailing address. 'Cut
Price Software' are not the worst company I have dealt with however,
that honour goes to 'White House Computer', in America who have had
my money for two years! Though the story is complicated it is true
to say that they have also ignored the considerable number of
letters I have written to them with the exception of one. About a
year ago I wrote a particularly rude letter questioning their
parentage and they did write back. Guess what they said? Correct,
they said I had not responded to any of their letters explaining
their problems. Again a promise to return my money but no cheque.
None of these errant companies actually claimed they had sent the
software which of course was the crux of the matter. If anyone knows
an American lawyer willing to take on an open and shut case then I
have all the evidence!
If Atari is to survive particularly at
the 'bottom cheap' (8-bit) end of the market then companies handling
their name have to be reputable and magazines like yours spread the
good word. If there are too many Atari 'computer cowboys' then
people are only going to buy computers where software and hardware
are available off the shelf to minimise their risk.
I have been taking PAGE 6 from the first
edition and have been impressed by its continuing to mature. I like
the outspoken editorials, and reviews which give opinions I value,
so more of the same please.
Ray Pinches
Teddington. Middx.
DOS MYSTERY?
Dear PAGE 6,
A minor query regarding DOS 2.5.
I am constantly SAVEing programs, modifying, saving,
etc. then deleting all the unwanted bits from the disk. Occasionally
a program appears with a '<' at one end of the filename and a ' > '
at the other. What is the significance of these two arrowheads?
A. Golding
Barnet
These are nothing to worry about. They simply mean
that either part of, or the whole of, a program is stored in sectors
that are numbered greater than 707, the enhanced density feature. If
you booted up with a DOS 2.0 disk and requested a directory, the
programs in the '< >' would not appear as DOS 2.0 uses single
density only.
KILL THAT QUERY!
Dear Les,
I am writing a small program that needs quite a bit
of input, and needless to say all those horrible question marks make
the display rather untidy. Is there a way of inputting without the
?.
P. Resuirata
Baghdad
This is something that puzzled almost everybody for
years and many people will still tell you that it is not possible to
get rid
of the question mark when prompting for user input without some
complex programming. But it is possible! And it is easy!
Just try the following lines
10 DIM A$(10)
20 ? "ENTER SOMETHING ";:INPUT #16,A$
30 ? A$
So
just use INPUT #16 when you don't want the ? but don't ask me why!
STOP THAT ST SCREEN
Dear Sir,
As I am new to the ST and computing in general would
you answer me a question?
I have various demo disks that have a file called
READ.ME. But when I load it to read, it whizzes down the screen and
I don't get a chance to read it! Sometimes I have managed to stop it
by pressing a key, but by then half of the message has disappeared!
What do I press so it is still at the beginning and then what do you
press to make it move up a screen at a time?
Patrick Olsen
York
The correct procedure for reading a text file on
screen is to double click on the file and then select Show. If the
file has been correctly stored on the disk the text should be shown
one screen at a time, pausing each time with a 'More ...' message.
Hitting Return will advance the text one line at a time and the
space bar will scroll another full screen into view. If you wish to
quit back to the desktop, just press Q. That's how it should work
but problems can arise as the result of the file not being properly
saved in the first place or being formatted for 80 column output and
being read in low resolution which only has a 40 column screen. The
solution to the latter is simple, just switch to medium resolution
and Show the file again. If it has been properly printed and
formatted in 80 columns you should have no problems in reading it.
If you still get the same problem. the only answer is to load the
file into a word processor like STWriter and then PRINT it to disk
rather than SAVE it. If you also set the right margin to less than
40 you should be able to read the file in low-res as well.
VIDEO TITLES
Dear Les,
I have just purchased a Sony Video 8 Camera and have seen video
magazines advertise 'titling' programs for Amstrad, Commodore etc.,
for adding titles to your video programs. Do you know of any program
to do this for the Atari? Or is there anyone out there who has the
'know-how' to do it?
H. W. Clark
Barking, Essex
Several readers have asked this over the years and the good news
is that Datasoft have just started advertising an Atari XL/XE
version of their Video Title Shop program. Hopefully this will be
released in the U.K. shortly through the licensing agreement with
U.S. Gold but it should be available anyway from those specialist
retailers who normally import American titles.
AIN'T WE GOOD ...
Dear Les,
Having received my latest copy of PAGE 6 I feel that
I must express my amazement at the quality and value for money. I
compared Issue 29 with Issue 1 and the improvement in the standard
of the magazine itself, as well as the listings, is vast.
I say that the listings have improved but this is no criticism of
the early programmers. Indeed, because of them (and of course PAGE
6) Atari enthusiasts world wide have learnt and developed their
skills. I would also like to thank you for publishing screen shots
of the listings.
May PAGE 6 continue to give help, encouragement and
enjoyment for years to come.
Mr. A.J. Wright,
Ipswich, Suffolk
... SURE ARE!
Dear PAGE 6,
I am the newsletter editor and vice president of our local users
group. We've received two issues of PAGE 6 as exchanges and to be
quite honest, it is probably the best 8-bit Atari publication in
existence. The type-in programs rival many commercial programs and
the amount of information presented is excellent.
Thanks for an excellent magazine and if there is anything we can do
for you here in the States, don't hesitate to ask.
Gordie Meyer,
Midwest Atari Group – Iowa Chapter,
Ames, Indiana, U.S.A.
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