; Clears all memory accociated with a thread
; inputs    a  = Thread ID
FreeThreadMem:
    push af
    push de
    push hl
    push ix
    ld hl,UserRAM
FTMLoop     cp (hl)
        jr nz,FTMSkip
        push hl
        pop ix
        call FreeMem
FTMSkip     inc hl
        ld e,(hl)
        inc hl
        ld d,(hl)
        add hl,de       ; jump to next section
        ld de,UserRAMEnd    ; get the end of UserRAM
        sbc hl,de       ; compare
        add hl,de
        jr nc,FTMLoop       ; loop again if hl < UserRAMEnd
    pop ix
    pop hl
    pop de
    pop af
    ret