Dear Les,
The Calendar program in Issue 3 was one of the first I have managed
to type in without a bug. However on checking some dates in the 1880's
the program was found to be incorrect. I am sure that there are many
of us for whom 'Grandad's birthday' would have been incorrectly
calculated. The reason is simple. The year 1900 was not a leap year.
England did not adopt the Gregorian calendar until 1752 and so I
can only offer modifications which will allow days between 1753 and
2099 to be calculated. The years 1800 and 1900 were not leap years-the
year 2000 will be a leap year. Modifications are as follows:
6
GRAPHICS 18:POSITION 6,4:? #6;"CALENDAR"
7
POSITION 4,7:? #6;"1753 TO 2099"
8
FOR Q=1 TO 2000:NEXT Q 335 IF YEAR<=1900 THEN D=D+1
336
IF YEAR<=1800 THEN D=D+l
355
IF YEAR=1900 AND B=29 THEN B=28
356
IF YEAR=1800 AND B=29 THEN B=28
428
IF D>=8 THEN D=1
Steve TuIIett,
Midlothian
____________
Dear Sir,
After purchasing Issue 2 of your magazine, I felt that I must write
to congratulate you and to send a subscription for the next six
issues.
I have a useful tip that you may wish to publish. Several of my
friends also own Atari 400's and it seems to be a common problem that
after several hours use, the whole thing seizes up. The keyboard
becomes inoperable and the machine refuses to LIST, RUN or even ERROR.
As the System Reset key is also disabled the only way out is to switch
off and start again, losing the resident program. To prevent this
happening, at the start of your program POKE 832,6. Upon doing this I
no longer had problems with a program which frequently disabled my
machine.
Tony Amesbury,
Doncaster
** Is this really true! Could this be the fix for Atari
'lock-up' that everybody has been searching for? Perhaps some of the
more technically minded readers could let us know what this POKE
actually does. I can find no reference to it in any of the Memory
Maps.
____________
Dear Sir,
With regard to T. C. Mayers' letter in Issue 2 concerning
difficulty in loading a program, I have some information which readers
might find useful.
Firstly, if you are having difficulty in CLOADing a program and
Error 143 or 140 appears at the beginning when the program is about to
load or, if after about a minute Error 138 or 143 appears, then note
whether the CLOADing sound is a high-pitched tone or a low-pitched
tone. If the tone is high then the computer is trying to read Data but
there is nothing there. Rewind the tape and then advance it 1 count on
the counter. If the same thing happens again then rewind and advance
it another count and so on until you get it right.
If the tone is low-pitched then the computer has begun reading Data
part way through a program. This usually happens when a program has
been recorded in the middle of a tape. Again rewind to where you
started to CLOAD and advance the counter one count at a time until the
program loads.
I hope that this will help some of your readers. As a final
warning, don't leave your program recorder near a television speaker
as this can de-magnetise the tape causing a loss of all your programs.
Congratulations on a great magazine. Keep up the good work.
Stuart
Norse,
Hoddlesdon,
Lancs.
____________
Dear Les,
Congratulations on a steadily improving magazine.
Maplin of Southend, Essex, do upgrades on the 400. They also state
that their uplift does not invalidate the Atari guarantee. I had my
400 converted in the same day. Very good service. I cannot say the
same for their Annual Subscription to Analog, at the moment they are
two issues behind. I am still waiting for issues 9 and 10 which have
been on sale locally for over two months. I am several issues missing
on Analog and Antic, any ideas where back issues can be obtained?
With regard to tape problems where you get a fault in loading, I
have found that by leaving the tape in the position where you have
Saved or Loaded a program causes the pinch wheel to put a kink in the
tape which will cause a faulty load, so always rewind your tape and
release all keys on the recorder.
Excellent Graphics on the Cricket Maths program. Continued success
to the magazine.
H. W. Clark,
Barking, Essex
____________
Dear Les,
In answer to your call on Memory boards, I purchased my 400 in
August 1981 with 32K fitted from new from Maplin. This board, although
reliable, did cause the left half of the TV screen to have vertical
lines. The degree of nuisance varied from program to program. As the
computer was new to this country at the time, I assume that the board
came from the States. I have now replaced this board with a 48K one
made by Calisto. This has got rid of the vertical line problem and
gives me a sharp fault-free picture. The shop I purchased the board
from is called Vision Store in Kingston-upon-Thames. The reason I went
there was solely due to the fact that a friend had his machine
upgraded there. I went to 48K because I have a feeling that the price
of Disk Drives is going to come down to a level that I can afford.
Back to the board. After a few days it suddenly would only show Memo
Pad mode whether it had Basic in or not. As the shop is not very near
to me I decided to open it up and take a look. I found that one of the
two extra wires that are soldered onto the cartridge connector was
adrift and the other one fell off soon after. I did a quick soldering
job and all was well. I wonder how many other computers have had
shoddy soldering jobs done?
John Shill,
Farnborough, Hants.
** From the rest of his letter it is obvious that John has some
electronics knowledge and without this I would not advocate taking
your Atari apart to check on faults. If you have problems ring the
shop where you had an upgrade done and get them to fix it quickly. A
good shop will help you. If you find delays in getting your machine
back, complain. Several people have written to say that they still
experience severe delays from Atari's new Service centres. If this is
so complain directly to Atari in Slough and ring them two or three
times a week until you get your machine back. If you sit back patiently,
everyone will assume that you are happy to wait. A Company's
reputation is built on Service and Atari took a step in the right
direction in setting up their Service centres, but they must be told
by you - the customers - if there are still delays and problems.
____________
Dear PAGE 6,
In First Steps you said that by pressing CTRL and 1 it stops the
screen scrolling. This is true but it explains it very well in the
Basic Reference Manual - page 14.
This must mean that you are saying the experts don't read their
manuals.
Nicholas Pearson,
Selby, Yorks.
** Quite right, Nicholas! Bill Wilkinson who wrote the Atari
Basic language actually admitted in his column in Compute! that he had
his machine for over a year before someone pointed out the CTRL 1
feature!
____________
Please keep sending your letters on any subject, either in answer
to queries raised by other readers or on matters that have not been
covered before. Also send in any hints and tips that you feel might
help other readers or amendments to any of the programs printed.
Finally, we are running short of small Demo programs and any short
programs demonstrating graphics or other functions would be
appreciated.
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