Sinclair ZX80 / ZX81 / Z88 Forums

Fascinating...combining four display lines at once.
dr beep is a WIZARD! (and I really do mean that in the nicest way possible)

You. Are. A. Machine! dr beep

I have an ZXpand+ and having trouble with wobble all the time. I ask the family not to breath near the table when I use the ZXpand+. Stange we can have so different experiences. Since I touched up each tab on the edge connector with a thin bead of solder, I've had no wobble problems, even with the ...

I did a bit more work on this, but still have some white bars at the top and bottom on the 60Hz build. The problem is that eliminating the white bars slows gameplay too much. So, here is where I've ended up.
50Hz 60Hz

Here is a 60Hz version for those, like me, afflicted with NTSC, including source code (compiled using TASM with NTSC defined). I'm stuck with a white line at the top because of how little processing time is left over for gameplay. Any ideas on how to remove it, if possible?

I love your suggestions, XavSnap.
You're such a trickster!

Hi, In BASIC, after a FAST/SLOW process, an unsightly scrolling can occur when exiting the FAST mode. To avoid this dropout of the screen frame, just add a PAUSE before the SLOW commande: 10 FAST (... your code..) 1000 PAUSE 0 1010 SLOW Have fun. ...and don't forget to add this line if running on f...

Sort of like the calculators of the day.

Internally accurate down to 1/(2^32) ~= 0.0000000002328306437. So, yes, 9 to 10 digits. 32/log2(10)=9.63, to be more precise.

The ZX81 is only capable of precision to 8 digits. Thus, the rounding.