Apple-2-SW/apple2_fantavision_reloaded
1
0
Fork 0
mirror of https://github.com/Michaelangel007/apple2_fantavision_reloaded.git synced 2024-12-27 01:32:14 +00:00
Code Issues Projects Releases Wiki Activity

Clean P5 Boot vars

Browse Source
This commit is contained in:
Michaelangel007 2017-03-26 13:00:59 -07:00
parent f5d9bd85a8
commit 5c4df0a80c
1 changed files with 4 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
README.md
View File

@ -313,12 +313,11 @@ but I'll be nice guy and provide a fully documented disassembly:
; Disk Drive P5 PROM Usage ZP and IO
P5.Dest = $26 ; 16-bit pointer to dest
P5.SlotX16 = $2B ; i.e. $60 = Slot 6
P5.TrackHave = $40
P5.WantTrack = $41 ;
P5.Nibs = $3C ; counter for $56 nibbles
P5.SecWant = $3D ;
P5.SecTotal = $0800 ; T00S0 @ $00: total number of sectors to load
P5.TrackHave = $40
P5.TrackWant = $41 ;
PHASE_MASK = $03 ; 4 phases
PHASE0_OFF = $C080
@ -417,7 +416,7 @@ but I'll be nice guy and provide a fully documented disassembly:
0852:A9 0F LDA #$0F ; Num Sectors to Read
0854:85 52 STA NumSecLeft ;
0856:A9 15 LDA #$15 ; Track $15 contains Boot Stage 2
0858:85 41 STA P5.WantTrack ;
0858:85 41 STA P5.TrackWant ;
085A:0A ASL ; $15 * 2 = $2A Half-Tracks
085B:20 81 08 JSR BS.HalfTrackSeek ;v $0881