Kev's Development Toolbox

August 17, 2021November 5, 2021

Packet Radio: ax25 node logon message: updating for a cleaner menu

After logging on to an ax25 node, you’re shown a message like this:

DAVBBS:KK6DCT-6 Welcome to KK6DCT-6 network node

Type ? for a list of commands. help <commandname> gives a description
of the named command.

--

@kk6dct-6 20:52:01>

This is what is shown by my node that I’m currently setting up. I’d like to show a list of the apps I currently have configured. You can see the configured commands by entering a ? as the message tells you, but the formatting is not ideal, especially as I’m adding more apps and this list is getting cluttered. This is what the ‘?’ command shows for my currently configured apps:

@kk6dct-6 20:52:01> ?
DAVBBS:KK6DCT-6 Commands:
?, Advent, Bye, Connect, Escape, Finger, Help, HItchhikers, HOst
Info, Links, Mheard, NLinks, Nodes, PIng, Ports, Routes, Status
TAlk, Telnet, TIme, Users, W1-WeatherDavisCA, W2-Weather5DaysDavisCA
W3-WeatherForCity, W4-Weather5DaysForCity, Z1-Zork1, Z2-Zork2
Z3-Zork3, ZConnect, ZTelnet

When you logon, the first part of the welcome message that’s displayed is configured in /etc/ax25/node.motd (message of the day). Editing this file I can now more cleanly format the menu (and I might come back and change some of the names of the apps to make the menu options clearer later) :

DAVBBS:KK6DCT-6 Welcome to KK6DCT-6 network node
  W1		- Weather in Davis, CA
  W2		- 5 day weather forecast: Davis, CA
  W3		- Weather in specified city
  W4		- 5 day weather forecast for specified city
  Advent	- Adventure / Colossal Cove
  Z1		- Zork I
  Z2		- Zork II
  Z3		- Zork III
  
Type ? for a list of commands. help <commandname> gives a description
of the named command.

--

Much better!

August 16, 2021August 16, 2021

Mapping xml to Java POJOs with Jackson

Jackson is typically used for Json serialization and deserialization, but with the jackson-dataformat-xml dependency you can also use Jackson to easily map to/from XML too.

Maven dependencies:

	<dependency>
	    <groupId>com.fasterxml.jackson.core</groupId>
	    <artifactId>jackson-core</artifactId>
	    <version>2.12.4</version>
	</dependency>
	  
	<dependency>
	    <groupId>com.fasterxml.jackson.dataformat</groupId>
	    <artifactId>jackson-dataformat-xml</artifactId>
	    <version>2.12.4</version>
	</dependency>

If you have additional elements and attributes on elements that you’re not interested in, similar to Json, just add the ignore annotation at class level:

@JsonIgnoreProperties(ignoreUnknown = true)

In some XML docs you can have elements with the same name at the same level without a parent to exclusively group those elements. For example you can have xml that looks like this with a grouping:

<example>
    <name>example1</name>
    <items>
        <item>1</item>
        <item>2</item>
    </items>
</example>

This would be automatically handled by Jackson if your POJO class has a list of Item called items:

private List<Item> items;

but sometimes you’ll have a doc that looks like this:

<example>
    <name>example1</name>
    <item>1</item>
    <item>2</item>
</example>

To map this you need to use this annotation:

@JacksonXmlElementWrapper(useWrapping = false)
private List<Item> item;

August 11, 2021November 23, 2024

Atoll locations in Microsoft Flight Simulator 2020 (part 1)

I’ve been doing some sightseeing in Microsoft Flight Simulator, flying over some of the major atoll locations around the world, and other famous Pacific island locations (e.g. Wake Island, featured in many Battlefield and other games)

The Maldives has many atolls spread across a whole archipelago of islands

VRMO Kooddoo – North eastern rim of the Huvadhu Atoll, Maldives

https://en.wikipedia.org/wiki/Kooddoo

This airport doesn’t appear to be in MSFS.

Kadhdhoo, Maldives

https://en.wikipedia.org/wiki/Kadhdhoo

Thimarafushi – Thaa Atoll, Maldives

https://en.wikipedia.org/wiki/Thimarafushi_(Thaa_Atoll)

https://skyvector.com/airport/VRNT/Thimarafushi-Airport

This is an odd one – in MSFS the island with the airport is just rendered as a large blocky beach:

Chuuk Lagoon, Micronesia – Chuuk International Airport PTKK

https://en.wikipedia.org/wiki/Chuuk_International_Airport

This is a view from approx 8000ft, the southeast rim of the atoll and looking back towards larger islands in the center:

I’ll follow up with another similar post soon.

August 11, 2021August 21, 2021

Telnet BBSes and other things – part 2

A while back I posted about a number of BBSes that are accessible online, and can therefore be easily ‘dialed’ with ATD using a WiFi Modem over the internet. I recently came across this huge list of online resources accessible via telnet and took a look through some of them: https://www.jumpjet.info/Offbeat-Internet/Public/TelNet/url.htm

It seems like most of these are no longer accessible. The library online catalogs all seem to no longer be available. It’s not surprising given the insecure nature of telnet, and accessing library catalogues via your browser would be a much more secure and user friendly experience.

There’s a few things in this list that are interesting however. Ignoring the massive list of BBSes, there’s a few other oddities that are worth checking out and as of posting this, are still up and available. Here’s a few that I tested out using an Atari ST running the Taz terminal software, connected to my VT132 modem/terminal.

lynx.scramworks.net

Need access to the web but your older computer doesn’t have a browser and/or is limited to text? This site is running a telnet accessible copy of Lynx, the text mode browser. Works just as you’d expect if you were running it locally.

nethack.alt.org

Online version of the all time classic dungeon crawler, nethack

Zork and many other text based adventures: zork.retroadventures.net 6502

I’ve played around with frotz before, looking at getting some text adventures running over Amateur Radio using Packet. If you fancy accessing some classic text adventures online, this site has plenty, and there’s background info on how this was setup here:

Viewdata, glasstty.com and Telstar

Here’s an interesting one. If you were into computers in the UK in the 1980s you probably heard of BT’s Prestel service, and even if you’re not familiar with it, you’ll recognize the graphical style if you ever used Ceefax or Oracle on your TV. glasstty.com have a service called Telstar, which is a recreation of a Viewdata/Videotext system. It can be accessed online with a Viewdata terminal client app (details in the link above), or even online via a browser here.

Unfortunately the only Viewdata terminal app for the Atari ST seems to be FaSTcom, but that app crashes on my ST when it loads (I have TOS 1.04, not sure if that’s an issue or not).

Connecting with a regular VT terminal app loses all the color formatting of the pages, but you can still connect with ATDglasstty.com:6502 :

Henderson Field, Midway Island – PMDY

Bora Bora Airport – NTTB

Wake Island – PWAK

Great Chagos Bank