Putting it to Work Ok, Ok, I can hear it now; it’s just another simultaneous equation program. Anybody can write one or at least find one in a good computer math book (they seem to be proliferating these days), besides what good are they anyway? I’d now like to present Part 2 in a continuing
Math Development Program, Part 2 Read More »
Unlocking the complexities of electrical circuits, this analysis uses simultaneous equations to untangle the mysterious world of currents and resistances in a Wheatstone Bridge.
Wheatstone Bridge Circuit Using S.E. in Electronics Read More »
Unravel the mystery of Simultaneous Linear Equations, understand their practical applications, and see how these mathematical systems can unlock everyday puzzles.
Math Development Program Read More »
Unleash the power of grey graphics characters for data plotting, with the same vertical resolution as PLOT commands. Discover how to plot in two shades, creating striking visual effects on a dark background.
Greyplot Dual Display Technique Read More »
This subroutine draws an unbroken line segment between pixel (X1,Y1) and (X2,Y2). It is based on the equation for a straight line, Y=M*X+B where M is the slope and B is the Y-intercept. First the slope is evaluated in line 1020, after making sure that (X2-X1) is non-zero (division by zero is a no-no). If
Straight Line Subroutine Read More »
This program converts between polar notation (magnitude and angle) and rectangular (or “Cartesian”) notation (“X” and “Y” values) of vector quantities and complex numbers. Many scientific calculators have this function, which often proves useful if you deal with vectors or phasors. On the ZX81, this can be accomplished quite easily using the SIN, COS, ArcTaN,
Polar-Rectangular Conversion Read More »
Here’s a neat program that Bill has allowed us to print, hoping that some of you will avail yourselves of his other programs. Drop him a line at the above address for his current product list. This program, like all Soft-way programs, is tightly coded and numbered consecutively. You may wish to re-number using a
You may have wanted to change RAMTOP without wiping out what you have in memory. It is not enough to simply POKE 16388 and 16389 with the desired RAMTOP, since the machine-code stack stays in the same place until you relocate them using NEW. Several “fixes” have been reported, including one using a ROM call
Change RAMTOP Without NEW Read More »
Here’s that article, promised in issue 1:3, to help get new 64K RAM owners off the ground. Since the Z80 has 16 address lines, the number of possible address combinations is 2**16=65536 (or 64K, or 10000h; one greater than FFFFh, the highest address). If we look at the possible states of A14 and A15 (the
The 16K Hot-Z II has a minor “bug” which causes the program to wipe the bytes from 8000h-8020h when you QUIT the program. If you’re storing complete BASIC programs in the 8009-BFFF range, this will “eat” some system variables stored up there. The author supplies this fix: load HOT-Z, and then use it to load
Here is a short listing you might find useful. I developed it after trying to find the mistakes, and there were several, in a 12K long program that I hand-loaded from a magazine listing. My eyes could not take the strain of staring at the TV and then the listing, back and forth over and
