Apple-2-SW/apple2_hgr_font_tutorial
1
0
Fork 0
mirror of https://github.com/Michaelangel007/apple2_hgr_font_tutorial.git synced 2024-06-04 06:29:32 +00:00
Code Issues Projects Releases Wiki Activity

Cleanup table header, and Ex. 2 hint

Browse Source
This commit is contained in:
michaelangel007 2016-01-10 14:50:30 -08:00
parent e445a9fb0e
commit de7199a15b
1 changed files with 6 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
README.md
View File

@ -1294,8 +1294,8 @@ For our final trick we are going to copy the characters off the text screen onto
The text screen, like the HGR screen, is also non-linear, and also broken up into a triad:
|Row|Row2TextAddr|Row2HgrAddr|
|--:|:----:|:------:|
|Row|Text Addrress|HGR Address|
|--:|:----:|:----:|
| 0 | $400 |$2000|
| 1 | $480 |$2080|
| 2 | $500 |$2100|
@ -1427,13 +1427,15 @@ Hey! Homework? Yes, the only (true) way to demonstrate you understand the theo
* one scan line (1 pixel)
Hint: For scrolling up one pixel we can spot the pattern if we inspect the memory flow of how pixels get shuffled around:
Hint: For scrolling up one pixel we can spot the pattern if we inspect
the memory flow of how pixels get shuffled around:
40 bytes from $2400.$2427 -> $2000.$2027
40 bytes from $2800.$2827 -> $2400.$2427
etc
Don't forget that you only need to copy 191 rows, not 192, since the very bottom scanline should be "blank."
Don't forget that you only need to copy 191 rows, not 192, since the
very bottom scanline should be "blank."
## Conclusion