; Clears all memory accociated with a thread
; inputs    a  = Thread ID
FreeThreadMem:
    push af
    push bc
    push de
    push hl
    ld hl,UserRAM
    ld d,a
FTMLoop     ld a,(hl)
        push hl
        pop ix
        cp d
            call z,FreeMem
        inc hl
        ld b,(hl)
        inc hl
        ld c,(hl)
        add hl,bc   ; jump to next section
        inc hl
        inc hl      ; skip the footer
        ex de,hl    ; put the location in de
        ld hl,-UserRAMEnd   ; get the end of UserRAM
        add hl,de   ; compare
        ex de,hl    ; put it back in hl
            jr z,FTMLoop    ; loop again if
            jr c,FTMLoop    ; hl < UserRAMEnd
    pop hl
    pop de
    pop bc
    pop af
    ret