midi irq 800b jumps right to a151.


with bit 7 clear in e100:
-------------------------
> p 800b
> n 5
Next PC: A151:  3476 B6E1    PSHS  U,Y,X,B,A
Next PC: A153:  B6E1 002A    LDA   >$E100
Next PC: A156:  2A51 8530    BPL   >$A1A9
Next PC: A1A9:  3576 3B35    PULS  A,B,X,Y,U
Next PC: A1AB:  3B35 06DD    RTI 


with bit 7 set in e100 (0x80):
------------------------------
> p 800b
> n 11
Next PC: A151:  3476 B6E1    PSHS  U,Y,X,B,A
Next PC: A153:  B6E1 002A    LDA   >$E100
Next PC: A156:  2A51 8530    BPL   >$A1A9
Next PC: A158:  8530 271D    BITA  #$30
Next PC: A15A:  271D B682    BEQ   >$A179
Next PC: A179:  8501 2728    BITA  #$01
Next PC: A17B:  2728 8D5C    BEQ   >$A1A5
Next PC: A1A5:  8502 260D    BITA  #$02
Next PC: A1A7:  260D 3576    BNE   >$A1B6
Next PC: A1A9:  3576 3B35    PULS  A,B,X,Y,U
Next PC: A1AB:  3B35 06DD    RTI

with 0x90 in e100:  
------------------
reads from 8237
> p 800b
> w e100 90
> n 5
Next PC: A151:  3476 B6E1    PSHS  U,Y,X,B,A
Next PC: A153:  B6E1 002A    LDA   >$E100
Next PC: A156:  2A51 8530    BPL   >$A1A9
Next PC: A158:  8530 271D    BITA  #$30
Next PC: A15A:  271D B682    BEQ   >$A179
Next PC: A15C:  B682 3727    LDA   >$8237
Next PC: A15F:  2702 97CE    BEQ   >$A163
Next PC: A163:  BDA0 94B6    JSR   >$A094
Next PC: A094:  CCA2 4ADD    LDD   #$A24A
Next PC: A097:  DDC0 7F82    STD   <$C0
Next PC: A099:  7F82 357F    CLR   >$8235
Next PC: A09C:  7F82 367F    CLR   >$8236
Next PC: A09F:  7F82 3739    CLR   >$8237
Next PC: A0A2:  3934 46DC    RTS



label a097 point_midi_hand_vec_to_rts
label f1bb set_qch_wtab_ptr_to_10
label f1c7 set_qch_osc_ctl_to_63
label f1d8 huge_delay