Thursday, September 14, 2017

Mounting Ubiquiti UniFi AC Access Points

I recently had my new house wired, so that I could install my long-serving Ubiquiti AC access points onto the ceiling, with no visible wiring.  I noticed, after I hired an electrician to install ceiling boxes, that Ubiquiti's rotary mount has 2 significant flaws:


  1. The holes provided for wall/ceiling mounting do not match either the US 2-3/4" or 3-1/2" ceiling box mounting holes.
  2. The rotary mounting plate has a release lever that is almost impossible to access, once it is mounted on the ceiling, as the level is almost flush with the bottom of the access point.
I created, based on the work of several other folks, a US ceiling mount adapter, with a 20mm relief height, and posted it on Thingiverse:


This is a simple part, created in OpenSCAD, but I am inordinately proud of it, as it is the first 3D printed part that I have created, without any outside assistance.

I'll probably talk more about 3D printing, in the future.  I recently acquired a used Prusa i3 Mk2 printer, and have been highly satisfied with it.

Tuesday, September 12, 2017

Scrolling and screen

I've been using screen for a heck of a long time now, and it has always bugged me that scrolling back through history isn't the easiest.  However, I just ran into a great little bit of termcap data that you can add to your .screenrc:

# Enable mouse scrolling and scroll bar history scrolling
termcapinfo xterm* ti@:te@

With that line added, you can use mouse scrolling, which makes my screening that much happier!

Tuesday, July 25, 2017

Fedora 26, High DPI Monitors, and nVidia Optimus

I spent most of yesterday attempting to upgrade my primary laptop, an MSI Stealth Pro GS63VR, from Fedora 25 to Fedora 26. This was my second attempt, as the first attempt ended in failure, due to my inability to get graphics working with any server beyond VESA/framebuffer mode.

First, I cleaned off the drive, and did a new initial installation of Fedora 26, and applied all updates. To get the installer to not freeze my laptop, I had to install in failback video mode. Once the laptop was installed and patched, I then proceeded to troubleshoot the issues that prevented me from getting either Nouveau or nVidia Xorg drivers working.  After quite a bit of trial and error, I determined that there are several main issues.  First, on Fedora 25, I had just ignored the Intel component of nVidia Optimus, and just installed the closed-source nVidia driver.  That seems to no longer be possible, on my hardware, with Fedora 26.  Second, there is an ACPI issue, with a number of laptops based on EFI versions of the AMI BIOS.  Third, the default for Bumblebee (the open source Optimus solution) is to disable kernel modesetting, but for me, this breaks EDID.

So, here is the solution that I came up with, to install Bumblebee:
  1. Set the default for systemd to multi-user instead of graphical
    1. # systemctl set-default multi-user.target 
  2. Update Fedora 26 to -current
    1. # dnf update
  3. Reboot
  4. Follow Bumblebee docs from https://fedoraproject.org/wiki/Bumblebee 
    1. Check laptop graphics hardware
      1. $ lspci | grep VGA
      2. 00:02.0 VGA compatible controller: Intel Corporation HD Graphics 530 (rev 06)
      3. 01:00.0 VGA compatible controller: NVIDIA Corporation GP106M [GeForce GTX 1060 Mobile] (rev ff)
    2. Add the main Bumblebee repo
      1. # dnf -y --nogpgcheck install http://install.linux.ncsu.edu/pub/yum/itecs/public/bumblebee/fedora$(rpm -E %fedora)/noarch/bumblebee-release-1.2-1.noarch.rpm
    3. Add the Bumblebee managed nVidia repo
      1. # dnf -y --nogpgcheck install http://install.linux.ncsu.edu/pub/yum/itecs/public/bumblebee-nonfree/fedora$(rpm -E %fedora)/noarch/bumblebee-nonfree-release-1.2-1.noarch.rpm
    4. Install the required Bumblebee packages (note that libglvnd-devel is needed, even though the docs don't mention it) 
      1. # dnf install bumblebee-nvidia bbswitch-dkms VirtualGL.x86_64 VirtualGL.i686 primus.x86_64 primus.i686 kernel-devel libglvnd-devel
    5. Reboot
After the system came up, I started Xorg with 'startx', and my laptop froze. After some sleuthing, I figured out that my laptop has an AMI BIOS, with a compatibility issue with bbswitch and Optimus, from the Troubleshooting section, in the Fedora Bumblebee docs:
https://fedoraproject.org/wiki/Bumblebee#Compatibility_with_recent_laptops_that_have_American_Megatrend_BIOSes

To fix this issue:
  1. Add "splash acpi_osi=! acpi_osi='Windows 2009'", after "quiet" to the /etc/sysconfig/grub GRUB_CMDLINE_LINUX entry
  2. Rebuild grub2 config
    1. # grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg
After rebooting, I started Xorg successfully, but I noticed that my MSI GS63VR 4k was running Xorg @ 800x600, but 3D acceleration worked.

To fix the resolution problem:

  1. Remove "nomodeset", from the /etc/sysconfig/grub GRUB_CMDLINE_LINUX entry. I got the suggestion to remove "nomodeset" from https://forums.linuxmint.com/viewtopic.php?t=216235#p1131177
  2. Rebuild grub2 config
    1. # grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg
  3. After this, everything worked in 4k, as espected, so I set the default target to graphical, again
    1. # systemctl set-default graphical.target
Comments and suggestions are welcome!

Sunday, August 2, 2015

C128 VGA DAC Continuing Sales

I am absolutely amazed that this kit continues to sell in numbers. I have sold over 60 boards and kits, all over the world. Thanks so much to everyone who has ordered from me, and I hope that this amazing design, by Richard42, will help you to continue to enjoy your vintage computer, be it a Commodore 128, or any other. Unfortunately, family pressure is forcing me to temporarily discontinue availability of the kit. I hope to resume building them, in the future.

Thursday, March 6, 2014

Video DAC Assembly Information

This post is taken directly from a post that I made on Erik Klein's Vintage Computing Forums.
Here are a list of the parts required to build the video DAC.

QtyReferencePart NumberDescription
1R13309XBK-NDRES 309 OHM 1/4W 1% METAL FILM
1R14324XBK-NDRES 324 OHM 1/4W 1% METAL FILM
1R15365XBK-NDRES 365 OHM 1/4W 1% METAL FILM
2R4,R54.64KXBK-NDRES 4.64K OHM 1/4W 1% METAL FILM
1R64.32KXBK-NDRES 4.32K OHM 1/4W 1% METAL FILM
1R1913.0KXBK-NDRES 13.0K OHM 1/4W 1% METAL FILM
3R10,R11,R1210.0KXBK-NDRES 10.0K OHM 1/4W 1% METAL FILM
3R7,R8,R915.0KXBK-NDRES 15.0K OHM 1/4W 1% METAL FILM
4R3,R16,R17,R1875QBK-NDRES 75 OHM 1/4W 5% CARBON FILM
1R12.2KQBK-NDRES 2.2K OHM 1/4W 5% CARBON FILM
1R23.3KQBK-NDRES 3.3K OHM 1/4W 5% CARBON FILM
4C2,C3,C4,C5478-3193-NDCAP CER 0.1UF 50V 20% RADIAL
1C1493-1144-NDCAP ALUM 10UF 100V 20% RADIAL
1IC2296-3577-5-NDIC TRIPLE 3-IN NOR GATE 14-DIP
1IC1TC74ACT244PF-NDIC BUFF/DVR TRI-ST DUAL 20DIP
1IC3296-4348-5-NDIC QUAD 2IN POS-NAND GATE 14-DIP
1X1621-009-260-042-NDCONN DSUB PLUG 9POS R/A GOLD
1IC4AD8044ANZ-NDIC OPAMP VF R-R QUAD LP 14DIP
1POWERA1921-NDCONN HEADER VERT 2POS .100 TIN
1H2A1923-NDCONN HEADER VERT 6POS .100 TIN

And, the pinout of the H2 (video) connection, from left to right, with the DE-9 connector facing up, is:

Ground, horizontal sync, vertical sync, red, green, blue

The power connection pinout, from left to right, is:

+5 VDC, ground

The GBS-8220 board comes with 2 pigtails. Plug them in, as described in the 8220 manual, and the video DAC will be powered by downstream power from the 8220. Power the 8220 with a standard AC/DC power adapter.

You can use the following parts, from DigiKey, to put connectors onto the supplied pigtails, that will plug in to the DAC board.

QtyPart NumberDescription
8A100453CT-NDCONN SOCKET 22-26AWG TIN CRIMP
1A99617-NDCONN RCPT HSNG 6POS CST-100 II
1A99613-NDCONN RCPT HSNG 2POS CST-100 II

The DAC can be plugged directly in to either a Commodore 128 RGB connector, or to the back of a CGA or EGA IBM video card. Please note that, on an EGA card, the DAC only works in the CGA (low-res) modes, and not in 640x350.

In response to a number of requests, here is the schematic.  It's a bit messy, but it should be usable.

Wednesday, March 5, 2014

Parts Inventory

Just a quick note on my inventory:

DescriptionQuantity on HandQuantity on Order
C128 DAC PCB40
DAC Parts Kit60

Unless I say that I have parts in stock, here, any orders will be shipped as soon as their parts come in. Negative inventories represent orders received for which I do not yet have the parts.

Commodore 128/ CGA Video DAC Board Available

I just completed a new build of Richard42's fantastic Commodore 128 video DAC board.  This is a fantastic little board that, in combination with a Gonbes GBS-8220 arcade RGB scaler, produces great 16 color, with intensity, output on any modern VGA monitor.  To boot, the combination also works great with IBM CGA or low-res EGA cards!

I did two rounds of prototypes, and the following is what the final board looks like.  Please excuse the poor quality of my living-room photos.

Video DAC Front
Video DAC Back
I am now making these available to the vintage community for the price of what the components cost me, plus shipping.

If you would like to purchase one, I am offering several different ways to get it.

Please let me know if you have any comments. I'll work on getting some screenshots, as I was referring to some posted on Commodore128.org, but that forum seems to have gone down, rather unexpectedly.