thanks, now it's clearer to me how it works.
As I told yesterday I have some bordering effects (from left border to display line) on my real msx2 nms8245 ,but on blue msx there is not .
this is the asm code (I used wbass2)
the v9938 manual says that the hint occurs just after a displayed line
but when does exactly is it set between borders?
INTH: ORG &HD1D1
OUTI
OUTI
IN A,(&H99) ;read status 1
INC D ;set next int reg 19
LD A,D
OUT (&H99),A
LD A,E
OUT (&H99),A
INC B
JP Z,AFTER
FUORI: EI
RET
AFTER: LD A,(LUN) ;presets
LD B,A
LD A,(LINE)
LD HL,&HD300
LD D,A
OUT (&H99),A
LD A,E
OUT (&H99),A
XOR A
OUT (&H9B),A
CALL &HB7 ;ctrl/stop?
JP C,BASIC
JP FUORI
BASIC: LD C,&H99
LD A,(&HF3DF)
RES 4,A ;disable h.int
OUT (C),A
LD A,0+128
OUT (C),A ;write reg.0
LD A,(&HF3E0)
SET 5,A ;enable v.int
OUT (C),A
LD A,1+128
OUT (C),A ;write reg.1
XOR A ;select status reg.0
OUT (C),A
LD A,15+128
OUT (C),A ;write reg.15
IM 1
POP IX
EI
RET ;basic
SETUP: EI
HALT
DI
IN A,(&H99) ;clear pending vint
LD HL,&HD000
LD DE,&HD001
LD (HL),&HD1
LD BC,&H0101
LDIR
LD A,&HD0
LD I,A
IM 2 ;interrupt mode2 every interrupt will call &hd1d1
LD C,&H99
LD A,(LINE)
LD D,A
LD E,19+128
LD A,(&HF3E0)
RES 5,A ;disable v.int
OUT (C),A
LD A,1+128
OUT (C),A
LD A,1 ;select status reg1
OUT (C),A
LD A,15+128
OUT (C),A
NOP
IN A,(C) ;clear pending hint
OUT (C),D ;set interrupt line
OUT (C),E
LD A,16+128 ;indirect access to reg16
OUT (C),A
LD A,17+128
OUT (C),A
LD HL,&HD300 ;data pointer
LD A,(&HF3DF)
SET 4,A ;enable hint
OUT (C),A
LD A,0+128
OUT (C),A
LD C,&H9A ;palette
LD A,(LUN)
LD B,A
XOR A ;palette color reg0
OUT (&H9B),A
EI ;!!
HALT
LOOP: JP LOOP
LINE: DB 0
LUN: DB 212this is the basic
10 REM setup &hd225
20 REM palette1.asm
30 DEFUSR=&HD225
40 POKE&HD283,0:POKE&HD284,212
50 VDP(19)=0:VDP(10)=VDP(10)OR2:VDP(9)=VDP(9)OR&B00100000
60 SCREEN5
70 COLOR15,0,15:CLS
80 FORI=0 TO211:LINE(0,I)-(255,I),QMOD16:Q=Q+1:NEXT
90 CALLTURBOON
100 FORI=0TO511:POKE&HD300+I,0:NEXTI
110 CALLTURBOOFF
120 RESTORE140:FORI=0TO49:READA,B:POKE&HD300+K,A:POKE&HD301+K,B:K=K+2:NEXT
130 A=USR(0)
data ..................
{mod: did some (code) work

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