VPOSR/VPOSW

Address Name Description DFF004 VPOSR Read vert most sig. bits (and frame flop) DFF02A VPOSW Write most sig. bits (and frame flop)

Overview

Bit 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00 LOF I6 I5 I4 I3 I2 I1 I0 LOL xx xx xx xx V10 V9 V8

LOF = Long frame(auto toggle control bit in BPLCON0)

I0-I6 Chip identification:

• 8361 (Regular) or 8370 (Fat) (Agnus-NTSC) = 10
• 8367 (Pal) or 8371 (Fat-Pal) (Agnus-PAL) = 00
• 8372 (Fat-hr) (agnushr),thru rev4 = 20 PAL, 30 NTSC
• 8372 (Fat-hr) (agnushr),rev 5 = 22 PAL, 31 NTSC
• 8374 (Alice) thru rev 2 = 22 PAL, 32 NTSC
• 8374 (Alice) rev 3 thru rev 4 = 23 PAL, 33 NTSC

LOL = Long line bit. When low, it indicates short raster line.

V9,10 xx Hires chips only (20,30 identifiers)

• BEAMCON0
• Hardware