|High resolution printer programs|
|This program works rather like PLOT, except that it works only with the printer, and uses a square of 256x256 points to give 4 times better resolution.
You will need a 16k RAM pack to run this program. Before entering it, type:
to reserve some memory. If you don't the program warns you and won't run. Be careful to enter line 1 exactly as given: the RNDs and TAN must be entered using function mode, not spelt out. Note that there is a space after the symbol. The four full stops will have other characters POKEd into them after the first run of the program.
Two examples are given, differing only in the lines between 12 and 9980; No. 6 plots a "flower" shape, No. 7 plots a sine and cosine graph complete with axes. (Compared with the one you get using PLOT in chapter 18 of the ZX81 books). The computer should be put in FAST mode before running the program. Even so, there will be quite a wait before anything happens, and a further 4 minutes before printing is finished. Remember that the program has 256*256=65536 possible points to plot at.