🚀 go-pugleaf

In article <1992Dec28.131540.23725@nosc.mil> koziarz@halibut.nosc.mil (Walter A. Koziarz) writes:

a description of a character_mask... and a fragment of code... and then the
following arithmetic discussion...

>okay, my problem is -- how do I go about determining the 'start point' to get
>row 25, col 80 of the screen?  I interpret all the information that exists to
>tell me that I should use 9*24*128+79 to get me to the 80th column in row 25.
>*but* it doesn't work... what am I missing?  incidentally -- the arithmetic
>above is based upon _9_ scanlines per char, _24_ character rows, _128_ bytes
>per character rows and _79_ character-positions to 'skip' in the first scanline
>of character row 25 (see the example code, the '79' in mov si,79 *does* put me
>at row 1, col 80)...  I feel I *must* be missing something quite basic...

>Walt K.

ummmm, yes, I *was* missing something *very* basic...  there are *16*
scanlines, not 9...  using the relationship:

	rrow = 16*24*128+79

lets me place the character at row 25, column 80 using the code-fragment shown
earlier... (that code-fragment was originally written by W. Ching and was
re-printed in an article in "Z-100 Life Line", issue #17)

Many thanks to gern for giving me the key piece to this puzzle...

Walt K.