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Re: ProDOS Click at Boot? (was Re: ProDOS buzz code?)
Steve Nickolas wrote:
> On Thu, 28 Feb 2013, Jayson Smith wrote:
>
>> No, that's not what I mean, and someone else has provided code to do what
>> I
>> want. However, I am wondering why ProDos clicks the speaker like that at
>> boot? Is it supposed to serve some purpose, is it some byproduct of
>> something else it's doing, or what?
>> Thanks.
>
> It seems to do this twice during the bootstrap, once before resetting the
> TTY, and once at the end of some function. I haven't figured out more
> yet.
>
> -uso.
>
Here's the code from MliSrc.aii:
greet lda $c030 ; hit speaker
sta $c00c ; disable 80 columns (rev-e)
sta $c000 ; disable '80store'
jsr $fe84 ; SETNORM, clears inverse mode
jsr $fb2f ; INIT, sets up full window in text page 1
jsr $fe93 ; SETVID, resets output hooks at $36
jsr $fe89 ; SETKBD, resets input hooks at $38
cld
jsr home ; clear screen
ldx #slin2-slin1-1 ; move greeting to screen.
grt1 lda slin1,x ; "apple ii"
[... Display ProDOS title screen ...]
lda #$80
trb $C029 ;turn off bit 7 of NEWVIDEO
@notGS
machine m65C02 ;inhibit '816 instructions
lda $c030
rts
--
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