; EEPLOCK.a -- write-protect EEPROM
        include ioports.i
        lxi sp,0
; write-protect all EEPROM
;        mvi c,80h
;        call wpc
;        mvi c,90h
;        call wpc
        mvi c,0A0h
        call wpc
;        mvi c,0B0h
;        call wpc
;        mvi c,0C0h
;        call wpc

dogit:   jmp dogit

wpc:
; write-protect banks y0..y7
;  C = y0
; bank=y1 addr=5555 data=AA
        mov a,c
        inr a                   
        out BANK_SELECT_O
        lxi h,05555h
        mvi M,0AAh
; bank=y0 addr=6AAA data=55
        mov a,c
        out BANK_SELECT_O
        lxi h,06AAAh
        mvi M,055h
; bank=y1 addr=5555 data=A0
        mov a,c
        inr a
        out BANK_SELECT_O
        lxi h,05555h
        mvi M,0A0h
        call wait_10_ms
        ret

wait_10_ms:
        mvi c,20
w10:    out WATCHDOG_PET_O      ; pacify watchdog
        call wait_1ms
        dcr c
        jnz w10
        ret

; wait at least 1 millisecond
WAIT_1MS: 
        push psw
        mvi a,70        ; <seems to be right>
        out WATCHDOG_PET_O
WL1:    dcr a
        jnz wl1
        mvi a,70
WL2:    dcr a
        jnz wl2
        pop psw
        ret