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Re: Where does the "16 SECTOR" message come from?
sicklittlemonkey wrote:
> On Feb 20, 6:52 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:
>> The slot ROM (256 bytes) clearly reads the disk to determine whether
>> it is a 13-sector format or a 16-sector format, but the $C800 space
>> deosn't appear to belong to the disk controller.
>
> In fact, it looks like it's the slot code that's bank switched via a
> store to $CX80. This should make it easier to dump. It detects the
> disk type, and then stores this code at $800:
>
> 800: LDA #$02 (#$03) ; bank number?
> 802: STA $CX80 ; select bank
> 805: LDA #$00
> 807: JMP $CX52 ($CX53) ; print "16 (13) SECTOR"? ... ;-)
>
> The values in parentheses are for 13 sector disks.
>
> Tristan, the slot ROM dump looks damaged. It isn't really all zeroes
> after offset EB is it? The code crashes as it is.
I checked it in the monitor just now. it's all 00 after EB.
Tristan.
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