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Amiga 500 512KB to 1MB internal RAM upgrade

Amiga 500 512KB to 1MB internal RAM upgrade Step 1: Check if your A500 PCB supports RAM upgrade  Some Amiga 500 revisions have room to expand the internal Chip RAM to 1MB, up from the original 512KB. My REV6A PCB has this option. You can see the empty RAM slots here: Step 2. Acquire the right RAM chips I've found some cheap Siemens HYB514256B-70 chips. The original ones on the motherboard are HYB514256b-60 (little bit faster, but not required for the A500). Another compatible chip is the TI TMS44C256-10N. You will need 4 of these chips. Step 3. Solder the RAM chips (or the sockets) Once you have the RAM chips, you can either solder them directly on the motherboard, or solder sockets and fit the RAM chips in the sockets (like I did). You can see 3 out of 4 sockets have the new RAM chip populated. Optionally power up the Amiga right now. Your new RAM won't be recognized yet, but the Amiga should boot, and the RAM chips should not get hot. If they do, they are broken or something
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[RPi4][ Using the PiMoroni Fan Shim on LibreElec including the LEDs!

I recently bought a brand new Raspberry Pi 4, and wanted to try Kodi on it. There is only one Kodi-distribution which has more or less decent support for RPi 4 at the moment, and that's LibreElec (although still Alpha). Since the RPi 4 is famously overheating and throttling without a fan or at least a heatsink, I got a PiMoroni Fan Shim. Nice piece of hardware, but their library cannot run on LibreElec, because they do not support installing python libraries through pip etc... On LibreElec, the whole rootfs is a read-only squashfs image. So there's no way you can install the Pimoroni python library on LibreElec, but I found an alternative: I found Phil Randal's blog at  http://www.philrandal.co.uk/blog/archives/2019/07/entry_214.html , where he described how to get at least the Fan portion of the Fan Shim working on LibreElec. I decided to build on that, and port the LED functionality to LibreElec as well, without the need for "pip install" or a
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Nice Spectrum Analyser... but does it run DOOM?

There's been quite some talk about the excellent Siglent SS 3021X Spectrum Analyser. It's a great piece of entry-level hardware, especially for the pricepoint. See: https://www.siglent.eu/siglent-ssa3021x-spectrum-analyser.html and: EEVblog's review/comparison: https://www.youtube.com/watch?v=gkLciTsjGZg It's also quite hackable: https://iw0ffk.wordpress.com/2017/01/29/hacking-the-spectrum-analyzer-siglent-ssa-3021x/ You can login over telnet using: root/ding1234 as login/password. ' dmesg ', ' cat /proc/cpuinfo ' and friends tell a lot about this device. It seems it's based on an am335x chipset from TI. http://www.ti.com/processors/sitara/arm-cortex-a8/am335x/overview.html The framebuffer is accesible throught /dev/fb0 Mmm.. let's run DOOM on this thing! Fetch the same toolchain Siglent used to compile software for this spectrum analyser: https://releases.linaro.org/archive/13.03/components/toolchain/binaries/ Compile my m
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Arch Linux: Fixing empty/blank windows for graphical applications that require root

When running applications such as "unetbootin" or "tuxboot", you might get a blank window, instead of the actual application. Even when running it through "gksudo", or having a decent polkit running (e.g. inside Gnome). E.g.: This is because these application use MIT_SHM (Shared memory), which for some reason does not work when running graphical applications as root, while being logged in as a regular user in X. The solution is to disable MIT_SHM. E.g.: $ sudo QT_X11_NO_MITSHM=1 tuxboot
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Getting backports to work with recent linux kernel releases

I have been struggling a few days now to get the fantastic "backports" project up and running on my machine (Arch Linux). Here's what I had to do: First, make sure you have backport checkout out, and pulled in all the required trees: # git clone git://git.kernel.org/pub/scm/linux/kernel/git/backports/backports.git # cd backports # ./devel/backports-update-manager  Here's what I found out: - Make sure your PYTHON_PATH does not contain funny stuff - devel/pycocci expects Python 2. Arch Linux defaults to Python 3. Use a virtualenv2, or change devel/pycocci's first line to "#!/usr/bin/env python2" - devel/pycocci crashes randomly when using different threads. I have hacked the script to make it single-threaded. EDIT: This seems to be because of Coccinelle 1.0.6. It does not occur using Cocinnele 1.0.4 - Coccinelle 1.0.6 does not work with all patches included in backports, you need version 1.0.4 with python support. (bin can be found here: ht
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Lock-ups and freezes w/ an STM32F4Discovery board with ST-Link v2, OpenOCD and GDB

This post is especially an outing of my joy now that I have finally resolved my issue debugging the STM32F4xx using OpenOcd. There exist many blogpost, tutorials, manuals about setting up an STM32F4Discovery + OpenOcd + gdb combo. I won't explain how to do it here, but it is an awesome, powerful and very cheap set-up. I chose the STM32F4Discovery board as the demo board for my course on embedded C, because it's cheap, full of features and has on-board debugging hardware. Writing a custom crt0, I ran into problems however. Stepping through the early init code, assembly instruction per assembly instruction, gdb would just lock-up, freeze, at random moments. Not always on the same instruction, not always at the same moment. I could also set a breakpoint on a certain line, then type 'c' to continue, and the debugger would never break, or even respond to a Ctrl+C. Furthermore, using st-util, from the texane github ( https://github.com/texane/stlink ) would work.It&#
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A free TCPI/IP stack for embedded systems

Another awesome project I've been busy with: I'm working for a company ( TASS ) that is specialized in embedded systems development and consultancy, and we have been working for quite some time on the PicoTCP project. This is a TCPI/IP stack, with a small footprint (so very suitable for embedded systems) and a very complete feature-set. You can check it out for yourself, since it's free: (GPL v2, but dual-licensed should you want to use for your company) https://github.com/tass-belgium/picotcp We have demos of the stack running under linux with a virtual ethernet device (VDE), and on a whole bunch of development boards, such as the STM32F4 boards, a Ti Stellaris Board, a PIC24, ... Check it out!
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