The single-row painter became vml.s at $C000: one sys() paints all 24
rows, memmove and line-index fix-ups run in ML, and the keyboard buffer
is popped with IRQs masked. dall() repaints only the cursor row or the
whole screen, so j went from 17 to 0-3 jiffies. Loading now checks the
drive error channel and splits lines over 80 columns. The temporary
jiffy counters used to measure the speedup are removed; the numbers are
in NOTES.md.

Generated with Codebuff 🤖
Co-Authored-By: Codebuff <noreply@codebuff.com>

Power C on the C64 calls ML as sys(addr, &a, &x, &y); the bank argument
from the manual's C128 library page made sys() jump to $000F and crash.
The ML row painter now runs. Quitting resets through $FCE2 because Power C
owns BASIC's zero-page pointers. Notes and Power C skill updated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>