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cadaver
Registered: Feb 2002
Posts: 1160 |
Opinions on safe minimum $1c07 value?
Any opinions on safe values of $1c07 (disk drive interrupt/head stepper motor frequency on 1541-ish drives)?
I know $3a is the default, and $10 is something one should *never* go below. I quickly checked Remember's recent Gemini Wing release and there $20 was used. So I guess the minimum safe value, considering different disk drive clones etc. would be somewhere between $10-$20? |
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tlr
Registered: Sep 2003
Posts: 1790 |
Quote: how about checking if we're on the top/bottom border, and change transfer method for that part ? :) ofcourse sprited would be not allowed in there ;)
That's quite common.
Example (from the Superkit filecopier):
.C:3663 A2 07 LDX #$07
.C:3665 38 SEC
.C:3666 AD 12 D0 LDA $D012
.C:3669 E9 32 SBC #$32
.C:366b 90 04 BCC $3671
.C:366d 29 07 AND #$07
.C:366f F0 F5 BEQ $3666
.C:3671 8E 00 DD STX $DD00
.C:3674 48 PHA
.C:3675 68 PLA
.C:3676 24 EA BIT $EA
.C:3678 AD 00 DD LDA $DD00
.C:367b 4A LSR A
.C:367c 4A LSR A
.C:367d 4D 00 DD EOR $DD00
.C:3680 4A LSR A
.C:3681 4A LSR A
.C:3682 4D 00 DD EOR $DD00
.C:3685 4A LSR A
.C:3686 4A LSR A
.C:3687 A2 27 LDX #$27
.C:3689 4D 00 DD EOR $DD00
.C:368c 8E 00 DD STX $DD00 |
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DJ Gruby
Registered: Aug 2002
Posts: 30 |
Krill, you are the God! Thanks so much, now with your change the code seems to work and it doesn't load any garbage anymore, just an original file data: charin ldx #$03
charin1 sec
lda $d012
sbc #$03
and #$07
cmp #$07
bcs *-9
lda #$0b
sta $dd00
bit $dd00
bpl charin1Thanks, you rock! |
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