OS_Isq, Initialize prefix sequence

Register parameters

RST 20H, DEFW $D006
IN: HL = sequence buffer
OUT: -

Registers affected after return:
     A.BCDE../IXIY same
     .F....HL/.... different 

Notes

Internal operating system usage.

Clears buffer and sets buffer pointer. Buffer length is 22 bytes.

Related calls

OS_Wsq, write to prefix sequence