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ALTAIR 8800micro Build

9 Jul

ALTAIR 8800micro kit from Briel Computers



21 Dec

Pulse Audio
Prior to installation of gqrx make sure pulseaudio is available during build by installing the following:

Install gqrx
git clone
cd gqrx
mkdir build
cd build
qmake ..
make -j8
sudo make install

Typical device strings
For the b200:

For the X310 with LFRX in slot 2:

For the X310 with WBX in slot 1:

For the N210 with LFRX:

When switching between devices in gqrx the gain control changes will segfault the application.  Fix this by deleting the “gains” section in:

Sending gqrx audio to fldigi
Install fldigi with yum

Configure fldigi sound card to use pulseaudio, leaving server string empty

Launch pulseaudio volume control, and under recording tab, fldigi capture from monitor of built-in audio analog stereo, and set level to 0 dB.

Adjust fldigi waterfall upper signal level and signal range.

Adding new systems to Hyperspin

28 Nov

This example will add Colecovision.

Edit this file:

E:\HyperSpin\Databases\Main Menu\Main Menu.xml

To add a system entry:

<game name="Colecovision"/>


Create a new ini file by copying an existing one (such as Atari 5200.ini):




E:\HyperSpin\HyperSync Cloud\HyperSync Loader.exe

Add ColecoVision, set all to Default, and sync database.




Select GLOBAL system and click Emulators tab.

Select MESS and change path to:


Click Settings tab and change 7z Enabled to True and Extract Path to:


Select Colecovision system and click Emulators tab.

Set Rom Paths to:

E:\HyperSpin\HyperSpin_Ready\Cart Systems\Coleco - ColecoVision

Set Default Emulator to MESS




and test a game to be sure it launches.

Setting up NI GPIB-USB-HS under Linux

26 Jul

Mostly stolen from:

Note unlike the ni_usb_b, this is the ni_usb_hs so no firmware has to be loaded at boot, thus gpib_config can be called directly.

Get latest source code

Typical build in /usr/local/src with
sudo make install

Edit configuration
sudo vi /etc/gpib.conf

board_type = "ni_usb_b"
name = "gpib0"

Add udev rules
sudo vi /etc/udev/rules.d/99-linux_gpib_ni_usb.rules

SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", ATTR{idVendor}=="3923", ATTR{idProduct}=="709b", MODE="660", GROUP="username", SYMLINK+="usb_gpib"
SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", ATTR{idVendor}=="3923", ATTR{idProduct}=="709b", RUN+="/usr/local/sbin/gpib_config"
KERNEL=="gpib[0-9]*", ACTION=="add", MODE="660", GROUP="username"

sudo udevadm control –reload-rules

Note udev will not run the gpib_config at boot, so add it in rc.local
sudo vi /etc/rc.d/rc.local

exit 0

sudo chmod +x /etc/rc.d/rc.local
sudo systemctl enable rc-local.service
systemctl status rc-local.service

Now plug in the adapter and run ibtest
Reboot and run ibtest

Linux Multimedia

19 Jul

Logitech C615 HD Webcam
sudo vi /etc/udev/rules.d/99-webcam.rules

SUBSYSTEMS=="usb", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="082c", MODE:="0666"

sudo udevadm control --reload-rules

Dell XPS 13 Webcam
sudo vi /etc/udev/rules.d/99-webcam.rules

SUBSYSTEMS=="usb", ATTRS{idVendor}=="0bda", ATTRS{idProduct}=="5752", MODE:="0666"

sudo udevadm control --reload-rules

RPM Fusion Repository
sudo yum localinstall --nogpgcheck$(rpm -E %fedora).noarch.rpm$(rpm -E %fedora).noarch.rpm

GUVCView Webcam Recording
sudo yum install libwebcam guvcview

Change resolution to 1280×720 on XPS-13

Set sound device to hw:2,0 for Logitech webcam

Screen Recording
sudo yum install gtk-recordmydesktop

Set sound device to DEFAULT for Logitech webcam

May also need to use hw:0,0 (use arecord -l to list input devices)

Video Editing
sudo yum install openshot

Video Playback
sudo yum install vlc

Fedora 20 x86_64 Linux Install Notes

7 Feb

Hardware Configuration
2 TB HDD on Intel 6G SATA port 0, /dev/sda, (Windows 7)
96 GB SSD on Intel 6G SATA port 1, /dev/sdb, (Intel RST cache for Windows 7)
2 TB HDD on Intel 3G SATA port 2, /dev/sdc, (Shared Windows / Linux)
DVD on Intel 3G SATA port 4
240 GB SSD on Marvel 6G SATA port 0, /dev/sdd, (Linux)
Asus P8Z68 Deluxe/Gen3 Bios
RAID for Intel SATA controller
Marvel controller enabled
Boot order (DVD port 4, USB, HDD port 0)
Intel RST Option ROM
RAID0(Cache) for SSD port 1
EasyBCD installed on Windows boot partition.
Boot selection for Linux (/dev/sdd1) or Windows (/dev/sda1)

Fedora Boot CD
Tab at install to modify boot commands.
Remove quiet.

Network Config
IPV4: manual
IPV6: ignore

Location: Chicago

Software Selection
XFCE Desktop (development tools, extra plugins)

Choose 2 TB HDD (the last one in the list)
Automatic partitioning

After Reboot
Create user and add to admin group
Synchronize time over network

Change to (e.g. runlevel 3)
sudo rm /etc/systemd/system/
sudo ln -s /lib/systemd/system/ /etc/systemd/system/

Change GRUB
sudo vi /etc/default/grub and remove rhgb quiet
sudo grub2-mkconfig -o /boot/grub2/grub.cfg

If for some reason Intel RST was enabled during install, the above will re-scan for bootloaders


Update the System
sudo dnf update

Enable root Account
sudo passwd

Install Custom Shell Scripts
cp .bash_profile ~
cp .bashrc ~
cp .profile ~
cp .vimrc ~
sudo cp .bashrc /root

Directory Permissions
sudo chmod 777 /usr/local/src

Add Library Path to Linker
sudo vi /etc/
add /usr/local/lib
add /usr/local/lib64
sudo ldconfig

sudo /usr/bin/firewall-config
Change default zone to internal
Trust services as required

sudo system-config-printer
Search for network printer at
Use DirectJet port
Choose driver for Brother HL-5170DN
Use BR-Script3

sudo usermod -a -G audio username
(must reboot to take effect)

The nm-applet gives insufficent permission errors when changing WiFi due to startxfce4 instead of using a display manager. This will fix it:

sudo vi /etc/polkit-1/rules.d/50-org.freedesktop.NetworkManager.rules
polkit.addRule(function(action, subject) {
if ("org.freedesktop.NetworkManager.") == 0 && subject.isInGroup("myusername")) {
return polkit.Result.YES;

(must reboot to take effect)

Apple II Floppy Drive Cable Retention Clamps

8 Jul

The Apple //e I recently acquired was missing the floppy drive cable retention clamps. As you can see from the manual pages, they retain the cable against accidental pulling, which could possibly break the floppy controller.



However they also reduce electromagnetic emissions (EMI). The ribbon cable has a copper braid, which I assume runs the length of the cable. It does not terminate on the floppy drive so it would serve no purpose other than EMI shielding, and to reduce coupling between adjacent wires. Nonetheless, the braid ought to be electrically bonded to the chassis, hence the need for the retention clamps.


I made the clamps out of 1/2″ x 3/32″ brass flat stock available at most hardware stores. It comes in a 12″ length for about $6. Take a sharpie and ruler, and mark off 2″ increments. Draw a centerline down the stock, then mark off 1/4″ from the each 2″ increment; this is where the holes will be drilled. Center punch the holes marks.

Drill 3/32″ holes for the back-plates and 1/8″ holes for the front plates. Tap the 3/32″ holes to 4-40 NC. Saw across the 2″ marks and file the edges smooth. Mark off a notch 1.2″ x 0.1″ on one long edge of each piece, then file the notch.


The drive cable lug will sandwich between the two pieces, which in turn will be held to the chassis with 4-40 x 1/2″ machine screws.