'linux' Episodes

UMBCast 048 - Another World

     3/30/2014

It's time for episode 48 where I'll be discussing The 1991 Delphine Software cinematic adventure, Another World.

News:

We've just found out Dave Cummins, writer of Beneath a Steel Sky, passed away in 2008.

GoG.com will be releasing more games with Linux support.

Julian Gollop of X-COM fame has launched a kickstarter called Chaos Reborn.

Microsoft has released the source code for MS DOS 1.1 and Word for Windows.

It's the 25th anniversary of Space Quest 3!

We then get into the meat of the show, Another World. Story, gameplay, dev story and LOTS of emails!

Buy Another World on GoG:
http://www.gog.com/game/another_world_20th_anniversary_edition?pp=1106a1dda2d680438ecfb0bb70fd479c55a1791f

Buy Another World on Steam:
http://store.steampowered.com/app/233550/

YouTube play session:
https://www.youtube.com/watch?v=5ekfc0Pz6YA

Next time, I'll be covering the 1994 adventure game, Little Big Adventure.

Enjoy!


The Apache Web Server

     10/29/2019

Welcome to the History of Computing Podcast, where we explore the history of information technology. Because understanding the past prepares us for the innovations of the future! Today we’re going to cover one of the most important and widely distributed server platforms ever: The Apache Web Server. Today, Apache servers account for around 44% of the 1.7 Billion web sites on the Internet. But at one point it was zero. And this is crazy, it’s down from over 70% in 2010. Tim Berners-Lee had put the first website up in 1991 and what we now know as the web was slowly growing. In 1994 and begins with the National Center for Supercomputing Applications, University of Illinois, Urbana-Champaign. Yup, NCSA is also the organization that gave us telnet and Mosaic, the web browser that would evolve into Netscape. After Rob leaves NCSA, the HTTPdaemon goes a little, um, dormant in development. The distress had forked and the extensions and bug fixes needed to get merged into a common distribution. Apache is a free and open source web server that was initially created by Robert McCool and written in C in 1995, the same year Berners-Lee coined the term World Wide Web. You can’t make that name up. I’d always pictured him as a cheetah wearing sunglasses. Who knew that he’d build a tool that would host half of the web sites in the world. A tool that would go on to be built into plenty of computers so they can spin up sharing services. Times have changed since 1995. Originally the name was supposedly a cute name referring to a Patchy server, given that it was based on lots of existing patches of craptostic code from NCSA. So it was initially based on NCSA HTTPd is still alive and well all the way up to the configuration files. For example, on a Mac these are stored at /private/etc/apache2/httpd.conf. The original Apache group consisted of * Brian Behlendorf * Roy T. Fielding * Rob Hartill * David Robinson * Cliff Skolnick * Randy Terbush * Robert S. Thau * Andrew Wilson And there were additional contributions from Eric Hagberg, Frank Peters, and Nicolas Pioch. Within a year of that first shipping, Apache had become the most popular web server on the internet. The distributions and sites continued to grow to the point that they formed the Apache Software Foundation that would give financial, legal, and organizational support for Apache. They even started bringing other open source projects under that umbrella. Projects like Tomcat. And the distributions of Apache grew. Mod_ssl, which brought the first SSL functionality to Apache 1.17, was released in 1998. And it grew. The Apache Foundation came in 1999 to make sure the project outlived the participants and bring other tools under the umbrella. The first conference, ApacheCon came in 2000. Douglas Adams was there. I was not. There were 17 million web sites at the time. The number of web sites hosted on Apache servers continued to rise. Apache 2 was released in 2004. The number of web sites hosted on Apache servers continued to rise. By 2009, Apache was hosting over 100 million websites. By 2013 Apache had added that it was named “out of a respect for the Native American Indian tribe of Apache”. The history isn’t the only thing that was rewritten. Apache itself was rewritten and is now distributed as Apache 2.0. there were over 670 million web sites by then. And we hit 1 billion sites in 2014. I can’t help but wonder what percentage collections of fart jokes. Probably not nearly enough. But an estimated 75% are inactive sites. The job of a web server is to serve web pages on the internet. Those were initially flat HTML files but have gone on to include CGI, PHP, Python, Java, Javascript, and others. A web browser is then used to interpret those files. They access the .html or .htm (or other one of the other many file types that now exist) file and it opens a page and then loads the text, images, included files, and processes any scripts. Both use the http protocol; thus the URL begins with http or https if the site is being hosted over ssl. Apache is responsible for providing the access to those pages over that protocol. The way the scripts are interpreted is through Mods. These include mod_php, mod_python, mod_perl, etc. The modular nature of Apache makes it infinitely extensible. OK, maybe not infinitely. Nothing’s really infinite. But the Loadable Dynamic Modules do make the system more extensible. For example, you can easily get TLS/SSL using mod_ssl. The great thing about Apache and its mods are that anyone can adapt the server for generic uses and they allow you to get into some pretty really specific needs. And the server as well as each of those mods has its source code available on the Interwebs. So if it doesn’t do exactly what you want, you can conform the server to your specific needs. For example, if you wanna’ hate life, there’s a mod for FTP. Out of the box, Apache logs connections, includes a generic expression parser, supports webdav and cgi, can support Embedded Perl, PHP and Lua scripting, can be configured for public_html per-user web-page, supports htaccess to limit access to various directories as one of a few authorization access controls and allows for very in depth custom logging and log rotation. Those logs include things like the name and IP address of a host as well as geolocations. Can rewrite headers, URLs, and content. It’s also simple to enable proxies Apache, along with MySQL, PHP and Linux became so popular that the term LAMP was coined, short for those products. The prevalence allowed the web development community to build hundreds or thousands of tools on top of Apache through the 90s and 2000s, including popular Content Management Systems, or CMS for short, such as Wordpress, Mamba, and Joomla. * Auto-indexing and content negotiation * Reverse proxy with caching * Multiple load balancing mechanisms * Fault tolerance and Failover with automatic recovery * WebSocket, FastCGI, SCGI, AJP and uWSGI support with caching * Dynamic configuration * Name- and IP address-based virtual servers * gzip compression and decompression * Server Side Includes * User and Session tracking * Generic expression parser * Real-time status views * XML support Today we have several web servers to choose from. Engine-X, spelled Nginx, is a newer web server that was initially released in 2004. Apache uses a thread per connection and so can only process the number of threads available; by default 10,000 in Linux and macOS. NGINX doesn’t use threads so can scale differently, and is used by companies like AirBNB, Hulu, Netflix, and Pinterest. That 10,000 limit is easily controlled using concurrent connection limiting, request processing rate limiting, or bandwidth throttling. You can also scale with some serious load balancing and in-band health checks or with one of the many load balancing options. Having said that, Baidu.com, Apple.com, Adobe.com, and PayPal.com - all Apache. We also have other web servers provided by cloud services like Cloudflare and Google slowly increasing in popularity. Tomcat is another web server. But Tomcat is almost exclusively used to run various Java servers, servelets, EL, webscokets, etc. Today, each of the open source projects under the Apache Foundation has a Project Management committee. These provide direction and management of the projects. New members are added when someone who contributes a lot to the project get nominated to be a contributor and then a vote is held requiring unanimous support. Commits require three yes votes with no no votes. It’s all ridiculously efficient in a very open source hacker kinda’ way. The Apache server’s impact on the open-source software community has been profound. It iis partly explained by the unique license from the Apache Software Foundation. The license was in fact written to protect the creators of Apache while giving access to the source code for others to hack away at it. The Apache License 1.1 was approved in 2000 and removed the requirement to attribute the use of the license in advertisements of software. Version two of the license came in 2004, which made the license easier for projects that weren’t from the Apache Foundation. This made it easier for GPL compatibility, and using a reference for the whole project rather than attributing software in every file. The open source nature of Apache was critical to the growth of the web as we know it today. There were other projects to build web servers for sure. Heck, there were other protocols, like Gopher. But many died because of stringent licensing policies. Gopher did great until the University of Minnesota decided to charge for it. Then everyone realized it didn’t have nearly as good of graphics as other web servers. Today the web is one of the single largest growth engines of the global economy. And much of that is owed to Apache. So thanks Apache, for helping us to alleviate a little of the suffering of the human condition for all creatures of the world. By the way, did you know you can buy hamster wheels on the web. Or cat food. Or flea meds for the dog. Speaking of which, I better get back to my chores. Thanks for taking time out of your busy schedule to listen! You probably get to your chores as well though. Sorry if I got you in trouble. But hey, thanks for tuning in to another episode of the History of Computing Podcast. We’re lucky to have you. Have a great day!


The Advent Of The Cloud

     9/5/2019

Welcome to the History of Computing Podcast, where we explore the history of information technology. Because by understanding the past prepares us for the innovations of the future! Today we’re going to look at the emergence of the cloud. As with everything evil, the origin of the cloud began with McCarthyism. From 1950 to 1954 Joe McCarthy waged a war against communism. Wait, wrong McCarthyism. Crap. After Joe McCarthy was condemned and run out of Washington, **John** McCarthy made the world a better place in 1955 with a somewhat communistic approach to computing. The 1950s were the peak of the military industrial complex. The SAGE air defense system needed to process data coming in from radars and perform actions based on that data. This is when McCarthy stepped in. John, not Joe. He proposed things like allocating memory automatically between programs, quote “Programming techniques can be encouraged which make destruction of other programs unlikely” and modifying FORTRAN to trap programs into specified areas of the storage. When a person loading cards or debugging code, the computer could be doing other things. To use his words: “The only way quick response can be provided at a bearable cost is by time-sharing. That is, the computer must attend to other customers while one customer is reacting to some output.” He posited that this could go from a 3 hour to day and a half turnaround to seconds. Remember, back then these things were huge and expensive. So people worked shifts and ran them continuously. McCarthy had been at MIT and Professor Fernando Corbato from there actually built it between 1961 and 1963. But at about the same time, Professor Jack Dennis from MIT started doing about the same thing with a PDP-1 from DEC - he’s actually probably one of the most influential people many I talk to have never heard of. He called this APEX and hooked up multiple terminals on TX-2. Remember John McCarthy? He and some students actually did the same thing in 1962 after moving on to become a professor at Stanford. 1965 saw Alan Kotok sell a similar solution for the PDP-6 and then as the 60s rolled on and people in the Bay Area got really creative and free lovey, Cobato, Jack Dennis of MIT, a team from GE, and another from Bell labs started to work on Multics, or Multiplexed Information and Computing Service for short, for the GE-645 mainframe. Bell Labs pulled out and Multics was finished by MIT and GE, who then sold their computer business to Honeywell so they wouldn’t be out there competing with some of their customers. Honeywell sold Multics until 1985 and it included symmetric multiprocessing, paging, a supervisor program, command programs, and a lot of the things we now take for granted in Linux, Unix, and macOS command lines. But we’re not done with the 60s yet. ARPAnet gave us a standardized communications platform and distributed computing started in the 60s and then became a branch of computer science later in the late 1970s. This is really a software system that has components stored on different networked computers. Oh, and Telnet came at the tail end of 1969 in RFC 15, allowing us to remotely connect to those teletypes. People wanted Time Sharing Systems. Which led Project Genie at Berkely, TOPS-10 for the PDP-10 and IBM’s failed TSS/360 for the System 360. To close out the 70s, Ken Thompson, Dennis Ritchie, Doug McIllroy, Mike Lesk, Joe Assana, and of course Brian Kernighan at Bell Labs hid a project to throw out the fluff from Multics and build a simpler system. This became Unix. Unix was originally developed in Assembly but Ritchie would write C in 72 and the team would eventually refactor Unix in C. Pretty sure management wasn’t at all pissed when they found out. Pretty sure the Uniplexed Information and Computing Services, or eunuchs for short wasn’t punny enough for the Multics team to notice. BSD would come shortly thereafter. Over the coming years you could create multiple users and design permissions in a way that users couldn’t step on each others toes (or more specifically delete each others files). IBM did something interesting in 1972 as well. They invented the Virtual Machine, which allowed them to run an operating system inside an operating system. At this point, time sharing options were becoming common place in mainframes. Enter Moore’s Law. Computers got cheaper and smaller. Altair and hobbyists became a thing. Bill Joy ported BSD to Sun workstations in 77. Computers kept getting smaller. CP/M shows up on early microcomputers at about the same time up until 1983. Apple arrives on the scene. Microsoft DOS appears in 1981 and and In 1983, with all this software you have to pay for really starting to harsh his calm, Richard Stallman famously set out to make software free. Maybe this was in response to Gates’ 1976 Open Letter to Hobbyists asking pc hobbyists to actually pay for software. Maybe they forgot they wrote most of Microsoft BASIC on DARPA gear. Given that computers were so cheap for a bit, we forgot about multi-user operating systems for awhile. By 1991, Linus Torvalds, who also believed in free software, by then known as open source, developed a Unix-like operating system he called Linux. Computers continued to get cheaper and smaller. Now you could have them on multiple desks in an office. Companies like Novell brought us utility computers we now refer to as servers. You had one computer to just host all the files so users could edit them. CERN gave us the first web server in 1990. The University of Minnesota gave us Gopher in 1991. NTP 3 came in 1992. The 90s also saw the rise of virtual private networks and client-server networks. You might load a Delphi-based app on every computer in your office and connect that fat client with a shared database on a server to, for example, have a shared system to enter accounting information into, or access customer information to do sales activities and report on them. Napster had mainstreamed distributed file sharing. Those same techniques were being used in clusters of servers that were all controlled by a central IT administration team. Remember those virtual machines IBM gave us: you could now cluster and virtualize workloads and have applications that were served from a large number of distributed computing systems. But as workloads grew, the fault tolerance and performance necessary to support them became more and more expensive. By the mid-2000s it was becoming more acceptable to move to a web-client architecture, which meant large companies wouldn’t have to bundle up software and automate the delivery of that software and could instead use an intranet to direct users to a series of web pages that allowed them to perform business tasks. Salesforce was started in 1999. They are the poster child for software as a service and founder/CEO Marc Benioff coined the term platform as a service, allowing customers to build their own applications using the Salesforce development environment. But it wasn’t until we started breaking web applications up and developed methods to authenticate and authorize parts of them to one another using technologies like SAML, introduced in 2002) and OAuth (2006) that we were able to move into a more micro-service oriented paradigm for programming. Amazon and Google had been experiencing massive growth and in 2006 Amazon created Amazon Web Services and offered virtual machines on demand to customers, using a service called Elastic Compute Cloud. Google launched G Suite in 2006, providing cloud-based mail, calendar, contacts, documents, and spreadsheets. Google then offered a cloud offering to help developers with apps in 2008 with Google App Engine. In both cases, the companies had invested heavily in developing infrastructure to support their own workloads and renting some of that out to customers just… made sense. Microsoft, seeing the emergence of Google as not just a search engine, but a formidable opponent on multiple fronts also joined into the Infrastructure as a Service as offering virtual machines for pennies per minute of compute time also joined the party in 2008. Google, Microsoft, and Amazon still account for a large percentage of cloud services offered to software developers. Over the past 10 years the technologies have evolved. Mostly just by incrementing a number, like OAuth 2.0 or HTML 5. Web applications have gotten broken up in smaller and smaller parts due to mythical programmer months meaning you need smaller teams who have contracts with other teams that their service, or micro-service, can specific tasks. Amazon, Google, and Microsoft see these services and build more workload specific services, like database as a service or putting a REST front-end on a database, or data lakes as a service. Standards like OAuth even allow vendors to provide Identity as a service, linking up all the things. The cloud, as we’ve come to call hosting services, has been maturing for 55 years, from shared compute time on mainframes to shared file storage space on a server to very small shared services like payment processing using Stripe. Consumers love paying a small monthly fee for access to an online portal or app rather than having to deploy large amounts of capital to bring in an old-school JDS Uniphase style tool to automate tasks in a company. Software developers love importing an SDK or calling a service to get a process for free, allowing developers to go to market much faster and look like magicians in the process. And we don’t have teams at startups running around with fire extinguishers to keep gear humming along. This reduces the barrier to build new software and apps and democratizes software development. App stores and search engines then make it easier than ever to put those web apps and apps in front of people to make money. In 1959, John McCarthy had said “The cooperation of IBM is very important but it should be to their advantage to develop this new way of using a computer.” Like many new philosophies, it takes time to set in and evolve. And it takes a combination of advances to make something so truly disruptive possible. The time-sharing philosophy gave us Unix and Linux, which today are the operating systems running on a lot of these cloud servers. But we don’t know or care about those because the web provides a layer on top of them that obfuscates the workload. Much as the operating system obfuscated the workload of the components of the system. Today those clouds obfuscate various layers of the stack so you can enter at any part of the stack you want whether it’s a virtual computer or a service or just to consume a web app. And this has lead to an explosion of diverse and innovative ideas. Apple famously said “there’s an app for that” but without the cloud there certainly wouldn’t be. And without you, my dear listeners, there wouldn’t be a podcast. So thank you so very much for tuning into another episode of the History of Computing Podcast. We’re lucky to have you. Have a great day!


Coherent Is Not UNIX!

     5/17/2020

In the current day Linux is the most widely used UNIX-like operating system. It's rise to prominence has been an amazing success story. From it's humble beginnings Linux has grown to power everything from super computers to car stereos. But it's not the first UNIX clone. A much earlier system existed, called Coherent. And as it turns out both Linux and Coherent share a lot of similarities. The biggest difference being that Coherent was closed source.

Like the show? Then why not head over and support me on Patreon. Perks include early access to future episodes, and stickers: https://www.patreon.com/adventofcomputing

Important dates in this episode:

1973: AT&T UNIX V4 Goes Public
1949: DOJ Sues AT&T Over Antitrust Violations
1975: AT&T UNIX V6 Released
1977: First Version of BSD Circulates
1977: XYBASIC Released by Mark Williams Company
1980: Coherent Released for PDP/11
1983: Coherent Comes to the IBM PC/XT
1995: Mark Williams Company Closes


Unix for the People, Part 2

     6/2/2019

Now, as the name suggests this is the second part of a series on the history of UNIX. Part 1 mainly covers the background leading up to UNIX. If you haven't listened to it yet, I strongly suggest you go do that now. A lot of what was covered in part 1 provides needed context for our discussion today.

 

Just as a quick recap, last time I told you about CTSS and Multics, two of the earliest time-sharing operating systems. Today, we are going to be picking up where we left off: Bell Labs just left Project MAC and decided to start their own time-sharing project. What they didn't realize was that this new project, called UNIX, would soon outshine all of its predecessors. But when this all started, in 1969 on a spare mainframe at Bell Labs, there was no hint at it's amazing future.


(OldComputerPods) ©Sean Haas, 2020