SHORTCUTS
ZX Computing, February 1987

The page where small is beautiful!


When we printed R.J. Kamphuis' HEX/DEC converter in the October issue
I commented on the fact that it only handled numbers 0 to 255 and
suggested that you may like to extend it to cover the usual range
0-65535. Several readers rose to the challenge, but by far the most
original is this effort from Mr. A. Welsh.


- - - - - - - - - - 
HEX/DEC
[file: Hex/Dec]

This program uses a trick with the RANDOMIZE statement. If the command
RANDOMIZE 32678 is entered then the two byte equivalent is stored in
the system variables called SEED at addresses 23670 and 23671.

If we then PEEK them and feed them into the original routine one after
the other then the conversion is achieved. Also included are the two
values of these addresses in decimal form and these are printed in the
machine code structure LOW byte / HIGH byte. You could of course
rearrange this if you prefer.

However, all good ideas usually have at least one drawback and the
main one with using this system is that RANDOMIZE 0 causes the number
to be placed in SEED to be completely random, although we probably all
know that 0 in decimal is 0000 in HEX. So, just for cosmetic purposes
the program also includes a line to trap input of 0 and to deal with
it separately.


- - - - - - - - - - 
FONT
[file: Font]

This routine is yet another variation on the 'thicker' character set
fonts that you all seem so keen on producing. We include this one
because it uses a different approach to that of most other programs of
this type and is interesting to compare with the more usual approach.

This one was supplied by Peter Zoetway of the Netherlands.


- - - - - - - - - - 
BIG COPY
[file: Big Copy]

Last month we published a Giant Copy program, this month we present a
copy routine that is not so large but, due to the shading effect,
produces a printout which would grace most computer room walls.

The program works with the usual ZX type of printer, Sinclair,
Alphacom, TS2048 or GP50S and prints in four sections which have to be
glued together.

Our thanks to Jean-Pierre Overbeek, yet another reader from Holland.


- - - - - - - - - - 
SCROLLER
[file: Scroller]

Another one from Holland, this time from Paul van Duijn. This is a
versatile screen scrolling program which operates on the top seven
lines of the screen. The program is located at address 30000 and
before use you need to set up exactly the way in which it operates by
using the following POKES:

POKE 30021, length_of_the_line (max 32 characters)
POKE 30001,8*PEEK 30021
POKE 30002,256-PEEK 30021
POKE 30013,start_position_of_line (0=0,0 and 255=7,31)

Paul suggests, and I found it to be true, that the best way is to
completely fill the screen lines 0 to 7 with some characters and then
experiment by poking the above addresses with various numbers before
calling the routine with LET l=USR 30000


- - - - - - - - - -
CALENDAR
[files: Calendar (PROG) + screen (SCREEN$)]

With the New Year upon us this program from old hand Robert Glavis is
most appropriate. It produces a unique calendar made up of SCREEN$,
either your own designs or using those of commercial programs.

As there are twelve months in the year you will need twelve screen$
pictures, PLUS an extra one for the title page telling you it's a
calendar or wishing Happy New Year etc. The program can be used for
years from 1987 to 1995.

A good idea is to get all thirteen pictures on one tape then simply
start and stop the tape each time the program requests and searches
for the next picture.

Many Happy New Years ...
