Recycling Old Computers with Linux: Pictures and Latest
Developments.
by Chad Hauris, Retro
Electronics and Audio Lab, Midland, Texas. 12/3/05.
I have been working on a few more projects with the old computers. One
was to get a Digital VT-320 terminal interfaced into the LAN. I did
this by connecting to the serial port on the HP computer. The computer
has 2 serial ports...1 is a front panel mounted port for a digital
camera interface and this is the one I hooked up to. I used a CAT 5
cable salvaged from building demolition work to run to the VT-320 in
the kitchen. I had on hand a 25 pin connector which I hooked to the end
of the cable and very luckily had an adaptor to connect to the DEC
terminal's cable which is like an enlarged phone connector.
Here is some very good information on terminals
and connecting
to the serial port at TLDP (The
Linux Documentation Project.)
The terminal is now working great!
One other thing I did is to create executable scripts to control the
CMUS audio player from remote terminals. When you download cmus, the
cmus-remote program is also included. You just log in from the remote
terminal as the same user as the host computer with the sound card
running cmus, and you can pass commands to the program.
One example is "cmus-remote -s" which stops the player.
I created a simple script for each command using the Joe editor. As
root, I changed permission on the files to allow them to be executed
(chmod +x filename). For example, I programmed the "q" file to decrease
the volume by a certain amount and the "f" file to reshuffle the
shuffle playlist. I created a "g" file to execute the command "links
www.google.com" so I could access google from the shell with 2
keystrokes.
Another problem I was having was a meltdown of Windows 98 on the
computer I used to record audio. I only used W98 here on this one
computer as I had not found any linux audio editors which would work
yet. Since W98 wasn't working, I installed Linux on this machine. I
then needed recording software!
I found the mhwaveedit
program and it works well but I had to use an older version of it as,
for some reason., I could not get the latest version to work. Now my
entire computer network is open source Linux and I will never go back
to Windoze again!
Please click the photos for larger views.
Here is the HP computer salvaged from Texas Recycles Day. Also, a
Gateway Pentium 200 mhz salvaged from a TRD 2 years ago. These are the
audio file playback units. You can see the serial cable leading from
the digital camera port to the VT-320 terminal.
This is the audio command center for the house. Clockwise from lower
left is a Sony turntable, Gates 16" turntable, Ampex 440 transport with
350 electronics, an equalizer for eq-ing 78 rpm records, the house PA
amp feeding the 70 volt distribution line plus a Marti compressor to
help maintain an even background music level, plus some cart machines.
Then there is the Broadcast Electronics "Spotmaster" 8 channel audio
board, and on top is the cueing amp and speaker for extra volume when
cuing up a record. There are the two monitors and keyboards for the
computers for instantaneous back-to-back audio playback.
Audio computer monitors. The left one is running CMUS and the right,
ALSAMIXER.
Here is the third computer in the audio command center, used for audio
recording. It is also the one this website is created on! It is running
the mhwaveedit
program here.
Of course, there has to be a bedside terminal for audio command center
control and text based web browsing from bed. This is a "smart"
terminal consisting of an IBM 75 mhz Pentium running Slackware 10.1 and
connected to the ethernet network.
No fancy interior design here! Just run the cables above the
door...there are cables for the private cable TV network, satellite TV
antenna input, Ethernet, telephone line, PA amplifier output from
DVD/Satellite, PA amplifier output from the audio command center, and
the Rabbit remote control extender to allow me to control the satellite
receiver from the bedroom.
Here is the VT-320 terminal in the kitchen, along with the trusty CO2
fire extinguisher.
Closeup.
Some future projects I have in mind include hooking up a private
telephone line to allow for modem access to the network from the barn,
parallel port control of relays, and setting up the TRS-80 computers I
got at an estate sale.
Click here to go
to some of the initial test results for the computers from July 2005..
Page 3, Improving
Performance and Audio Playback (part 1).
Features Page
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