Quick Mode by Fred Nachbaur

[GCHarder]

QUICK MODE for 1500-1000

by Fred Nachbaur

Syncware News v5n2

We leave the wonderful world of true hi-res for a
moment, to show you just one of any number of
fascinating possibilities that can result from
experimenting with the ZX81's interrupt-driven
display routines.

Tested in emulation only.

Regards;

Greg

[Moggy]

Works well enough on real kit but the double speed ROM we now have is faster so negates this somewhat and the "greyscale" image is a bit off putting, interesting concept never the less.

[GCHarder]

SLOW is SLOW, unless the new ROM fiddles with the video routines it should still be faster.

From a design perspective I always felt that an intensive program running in FAST mode, Mandelbrot Fractals for example, should always have a "take a peek" key. The most frustating thing with FAST mode is not knowing were it's at. FAST mode would still be preferred over Quick mode for intensive programs.

I think some monitors handle Quick mode better than others.

Greg

[Moggy]

SLOW is SLOW, unless the new ROM fiddles with the video routines it should still be faster.

From a design perspective I always felt that an intensive program running in FAST mode, Mandelbrot Fractals for example, should always have a "take a peek" key. The most frustating thing with FAST mode is not knowing were it's at. FAST mode would still be preferred over Quick mode for intensive programs.

I think some monitors handle Quick mode better than others.

Greg

From what I understand of it does have improved print routines as well as faster maths routines and finally gets rid of the annoying PAUSE "twitch", for example I have a BASIC chaotic number routine which simply prints a number, scrolls then rinse and repeat. Using a standard ROM the print and scroll is as expected somewhat plodding but when using the new ROM the print and scroll is so fast as to be almost unreadable. I would say that in this case it is a combination of both the improved maths and print routines working in concert rather than just print in isolation.

Using Fred's program my new ROM is about 3 seconds faster which may not be much but then again it is a very short running program and using the new ROM on longer calculations it makes a world of difference.