1 NOTES ON RADIOTRACK CARD CONTROL
2 by Stephen M. Benoit (benoits@servicepro.com) Dec 14, 1996
3 ----------------------------------------------------------------------------
4
5 Document version 1.0
6
7 ACKNOWLEDGMENTS
8 ----------------
9 This document was made based on 'C' code for Linux from Gideon le Grange
10 (legrang@active.co.za or legrang@cs.sun.ac.za) in 1994, and elaborations from
11 Frans Brinkman (brinkman@esd.nl) in 1996. The results reported here are from
12 experiments that the author performed on his own setup, so your mileage may
13 vary... I make no guarantees, claims or warranties to the suitability or
14 validity of this information. No other documentation on the AIMS
15 Lab (http://www.aimslab.com/) RadioTrack card was made available to the
16 author. This document is offered in the hopes that it might help users who
17 want to use the RadioTrack card in an environment other than MS Windows.
18
19 WHY THIS DOCUMENT?
20 ------------------
21 I have a RadioTrack card from back when I ran an MS-Windows platform. After
22 converting to Linux, I found Gideon le Grange's command-line software for
23 running the card, and found that it was good! Frans Brinkman made a
24 comfortable X-windows interface, and added a scanning feature. For hack
25 value, I wanted to see if the tuner could be tuned beyond the usual FM radio
26 broadcast band, so I could pick up the audio carriers from North American
27 broadcast TV channels, situated just below and above the 87.0-109.0 MHz range.
28 I did not get much success, but I learned about programming ioports under
29 Linux and gained some insights about the hardware design used for the card.
30
31 So, without further delay, here are the details.
32
33
34 PHYSICAL DESCRIPTION
35 --------------------
36 The RadioTrack card is an ISA 8-bit FM radio card. The radio frequency (RF)
37 input is simply an antenna lead, and the output is a power audio signal
38 available through a miniature phone plug. Its RF frequencies of operation are
39 more or less limited from 87.0 to 109.0 MHz (the commercial FM broadcast
40 band). Although the registers can be programmed to request frequencies beyond
41 these limits, experiments did not give promising results. The variable
42 frequency oscillator (VFO) that demodulates the intermediate frequency (IF)
43 signal probably has a small range of useful frequencies, and wraps around or
44 gets clipped beyond the limits mentioned above.
45
46
47 CONTROLLING THE CARD WITH IOPORT
48 --------------------------------
49 The RadioTrack (base) ioport is configurable for 0x30c or 0x20c. Only one
50 ioport seems to be involved. The ioport decoding circuitry must be pretty
51 simple, as individual ioport bits are directly matched to specific functions
52 (or blocks) of the radio card. This way, many functions can be changed in
53 parallel with one write to the ioport. The only feedback available through
54 the ioports appears to be the "Stereo Detect" bit.
55
56 The bits of the ioport are arranged as follows:
57
58 MSb LSb
59 +------+------+------+--------+--------+-------+---------+--------+
60 | VolA | VolB | ???? | Stereo | Radio | TuneA | TuneB | Tune |
61 | (+) | (-) | | Detect | Audio | (bit) | (latch) | Update |
62 | | | | Enable | Enable | | | Enable |
63 +------+------+------+--------+--------+-------+---------+--------+
64
65
66 VolA . VolB [AB......]
67 -----------
68 0 0 : audio mute
69 0 1 : volume + (some delay required)
70 1 0 : volume - (some delay required)
71 1 1 : stay at present volume
72
73 Stereo Detect Enable [...S....]
74 --------------------
75 0 : No Detect
76 1 : Detect
77
78 Results available by reading ioport >60 msec after last port write.
79 0xff ==> no stereo detected, 0xfd ==> stereo detected.
80
81 Radio to Audio (path) Enable [....R...]
82 ----------------------------
83 0 : Disable path (silence)
84 1 : Enable path (audio produced)
85
86 TuneA . TuneB [.....AB.]
87 -------------
88 0 0 : "zero" bit phase 1
89 0 1 : "zero" bit phase 2
90
91 1 0 : "one" bit phase 1
92 1 1 : "one" bit phase 2
93
94 24-bit code, where bits = (freq*40) + 10486188.
95 The Most Significant 11 bits must be 1010 xxxx 0x0 to be valid.
96 The bits are shifted in LSb first.
97
98 Tune Update Enable [.......T]
99 ------------------
100 0 : Tuner held constant
101 1 : Tuner updating in progress
102
103
104 PROGRAMMING EXAMPLES
105 --------------------
106 Default: BASE <-- 0xc8 (current volume, no stereo detect,
107 radio enable, tuner adjust disable)
108
109 Card Off: BASE <-- 0x00 (audio mute, no stereo detect,
110 radio disable, tuner adjust disable)
111
112 Card On: BASE <-- 0x00 (see "Card Off", clears any unfinished business)
113 BASE <-- 0xc8 (see "Default")
114
115 Volume Down: BASE <-- 0x48 (volume down, no stereo detect,
116 radio enable, tuner adjust disable)
117 * wait 10 msec *
118 BASE <-- 0xc8 (see "Default")
119
120 Volume Up: BASE <-- 0x88 (volume up, no stereo detect,
121 radio enable, tuner adjust disable)
122 * wait 10 msec *
123 BASE <-- 0xc8 (see "Default")
124
125 Check Stereo: BASE <-- 0xd8 (current volume, stereo detect,
126 radio enable, tuner adjust disable)
127 * wait 100 msec *
128 x <-- BASE (read ioport)
129 BASE <-- 0xc8 (see "Default")
130
131 x=0xff ==> "not stereo", x=0xfd ==> "stereo detected"
132
133 Set Frequency: code = (freq*40) + 10486188
134 foreach of the 24 bits in code,
135 (from Least to Most Significant):
136 to write a "zero" bit,
137 BASE <-- 0x01 (audio mute, no stereo detect, radio
138 disable, "zero" bit phase 1, tuner adjust)
139 BASE <-- 0x03 (audio mute, no stereo detect, radio
140 disable, "zero" bit phase 2, tuner adjust)
141 to write a "one" bit,
142 BASE <-- 0x05 (audio mute, no stereo detect, radio
143 disable, "one" bit phase 1, tuner adjust)
144 BASE <-- 0x07 (audio mute, no stereo detect, radio
145 disable, "one" bit phase 2, tuner adjust)
146
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