AUDIO SIGNALS
Raw
Audio
Filter
Cutoff (/LED)
The B2000 Extended Video Slot offers a few additional audio sig-
nals.
These are the left and right audio channels before they're passed
through the low pass filter on output. For many applications, the
audio sampling rate is low, and as such requires a low pass filter to
be in place at fc
=
6
kHz or so, to prevent audio aliasing. However,
higher sampling rates are possible, and in such cases, a much higher
filtering frequency is required for best possible sound. This raw
audio. left on pin
33
and right on pin
35,
is buffered but unfiltered.
This is the
/LED port line. In the B2000, as per the A500 convention,
this
signal is used to cut out the two pole low pass filter on the stan-
dard audio channels. When asserted, the filter
is
in place; when ne-
gated the filter is bypassed. This is an input to this Video connector,
useful to allow any
AudioNideo card to monitor the audio filtering
state. Pin 31
.
VIDEO SLOT PINOUTS
The original A2000 video slot is a
36
pin edge connector, the same
type as used on the
A2000's 16 bit
IBM
style bus extension.
PIN
1
3
5
7
9
11
13
1
S
17
19
2 1
23
25
27
29
3
1
33
35
Signal
Reserved for Expansion
Left Audio Out
Reserved for Expansion
Analog Red
Video Ground
Analog Green
Video Ground
Analog Blue
Video Ground
/C4 Clock
Video Ground
B0
=
D1
(47
Ohm)
B3
=
DB
(47 Ohm)
G3
=
DG
(47
Ohm)
R3
=
DR
(47
Ohm)
-5
VDC
XCLK
Reserved for Expansion
PIN
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
Signal
Reserved for Expansion
Right Audio Out
+
5
VDC
+
5
VDC
+
12 VDC
Video Ground
/CSYNC
IXCLKEN
BURST
Video Ground
IHSYNC
(47
Ohm)
Video Ground
NSYNC
(47
Ohm)
COMP SYNC (Analog)
IPIXELSW
(47
Ohm)
Video Ground
/C1 Clock
Reserved for Expansion
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