Commodore Amiga A500 Technical Reference Manual page 218

DMA
Time
Slot
Allocation
l Horizontal
Line
(Cont'd)
Five clocks must occur before the data which was fetched for a
particular position can appear onscreen. For example, if data
fetch start is specified as
38,
it will not be available for display
until clock number
45.
I
l
- I
l 3
I
3 2 0 m o a e
B I l - P l o o e O u r . 8 1 p l a n e
6 4 0
n o a s
~ ~ t - ~ ~ o n s O V A . b y p l a n s
5 - 1 9 some
a s c v c l e 4
1
A
hardware data-fetch stop has been installed a t count
D8
so as
I
to prevent the bit-plane data-fetch from overrunning the time
allotted for the memory refresh or disk
DMA.
E n d
H o r t z
L I n e
F e C c h
0
f
o n t a l
D a t a
C v c l e