Archive for the 'Uncategorized' Category

01
Oct
19

Old Tech: The AccessGrid

Today I’d like to talk about an old technology that has mostly died off and I used to use rather extensively in my job. The AccessGrid as it was known was an advanced teleconferencing system used world-wide for remote teaching and academic collaboration. Rather than being one single technology such as Skype, it was a collection of open source software that worked together, the main client simply being the glue that co-ordinated the meeting system. The main software was initially created in 1998 by Argonne National Laboratory and maintained by them until it was later made open source and supported by the community.

I was involved in running one of the AccessGrid nodes for my local university, mostly for the purposes of remote teaching. The rooms (also known as nodes) were set up with the ideal that the technology should be as transparent as possible for students and teachers. Most sites had a technician (usually referred to as the operator) that ran the equipment so that participants in a session didn’t have to manage the technology on top of their normal activity. The operator also usually participated with the AG community at large, helping each other with technical issues and testing the software and hardware configuration of nodes. I was the operator for our node, and am still involved in supporting remote teaching today.

A Typical AccessGrid node at University of Newcastle Australia

The room was equipped similarly to a class room, but with extra equipment to capture as much as possible. The front of the room had smart boards for writing notes and displaying lecture slides. For tutorial sessions students both remote and local could present solutions on the smart boards, although the exact technical solution used to provide this varied depending on the participating nodes. We had a number of cameras so all the local participants could be seen, and ceiling and lapel mics so students and teachers could be heard. These would usually be adjusted to some degree to suite each session, although sensible defaults would usually work fairly well.

Audio and Video was sent between clients using RTP (Real-time Transport Protocol) using Multicast UDP packets to transport the data. Because support for Multicast traffic isn’t universal and had been blocked at some institutions Unicast bridges were set up. These bridges allowed people with out Multicast support on their local network to connect to meetings, these bridges were run by nodes which had working Multicast support. Users could manually select which bridge to use to avoid high latency or traffic load.

Rat (robust audio tool) was the program that sent and received audio. It had options for many different bit rates and audio encodings and worked quite well on most platforms and audio equipment. It did have some basic echo canceling capability, but that usually wasn’t used as most nodes opted for hardware based echo canceling with devices such as the ClearOne XAP800 which generally did a better job. A notable feature of the software was the ability to tune the audio volume of each participant individually, which made it much easier to cope with audio issues as it could be adjusted on the fly. This unfortunately seems to be an unusual feature on modern communication software which often doesn’t allow this to be easily done.

Vic (Video conferencing tool) did the video portion of the session, by using multiple instances of this program it was possible for each node to transmit and receive video from multiple sources, usually cameras but also live screen captures from another program. This allowed a Node to send a video of the teacher, any local audience members, and multiple screen captures. Large sessions with many participants could have a large number of video streams, I remember seeing 15-20 streams for the bigger events. Generally it scaled fairly well, but you needed a decent internet connection.

The AccessGrid for Australian universities died rather unceremoniously and suddenly when the server was switched off most of the way through semester 2 in 2014. The person who was maintaining the server had left the institution where it was hosted, so when their server room was renovated it was decommissioned without any plans to reinstate the service. This happened with no announcements or notice, just one day it was suddenly dead. This left the still significant number of people using it for remote teaching scrambling to find alternative solutions as quickly as possible, thankfully most people managed, but it wasn’t fun.

Had the server not died, would the AccessGrid still be in use today? The answer is probably not, but maybe. As a technology it was harder to use and required significant technical knowledge. Modern software has largely taken that complexity and difficulty away, unfortunately taking some of the flexibility away with it. Commercial software often requires a license fee for the server at least, but in some cases also for the client software. This extra cost was off-putting to smaller institutions who don’t have the larger resources others do, so that may have motivated some to stick with it.

So why wax all nostalgic about it? Partly because no-one else has and the foot print the AccessGrid has on the internet is gradually fading. Also it was an interesting and formative technology in the electronic teaching space. It achieved results that at the time were not possible with other technologies enabling students access to courses they otherwise couldn’t reach, and Lecturers access to a wider audience. For me personally it was memorable being a part of the community and making the technology work. Whilst it had its problems it was interesting, functional, and flexible.

26
Oct
17

6th Anniversary!

Wow time sure catches up on you fast, recently my blog had its 6 year anniversary. It feels like much less than a year, probably because of how busy I’ve been. This year I’ve obviously been doing less writing, mostly because of how busy family commitments are keeping me at the moment. It’s not all bad, as only posting once a month has allowed me to spend more time on each one, and I’ve made a few minor improvements to the layout and writing as a result.

I’ve only got one motherboard left for that series of posts and I’ve finished the graphic library bench marking, so I’m contemplating what new stuff I’ll make. I’ve been considering making a short series revisiting my old BASIC programs one at a time. Not sure how this will work out, or how interesting it would be to readers, but it’s some thing I’d be keen to do. A series for teaching programming to absolute beginners is another idea, which I’m considering producing in a video format on youtube. It would require a bigger time investment, but would probably work better than the written form.

I’ll continue writing about MS-DOS games, largely because there’s plenty of material left, and I quite like writing the posts. I’ve got some shorter term hardware posts in mind as well, such as a few system overviews and revisiting some of my neglected machines that haven’t had a run in a while or are in need of repair. The Sparcstation 20 is one such machine, I have already written the first post, but unfortunately I’ve had difficulty getting packages to build under system emulation with Qemu and NetBSD 7.1 as there are occasional unexplained freezes. I have the X11 server enabled which may contribute to that, so I might try disabling that, a different version of Qemu, or perhaps running the build on the actual hardware instead.

Before I wrap up, just a quick comment on something I’ve seen happening on Ebay. I sometimes peruse the vintage computing sections and couldn’t help but notice that some machines are being parted out (dis-assembled and parts sold individually) to the point where even screws are being sold individually. I’m in two minds on this, I can understand doing this for something that is broken, but still has some usable parts. On the other hand I would be really unimpressed if people did this to otherwise working hardware. It appears this is happening sometimes. Also unimpressive is when sellers label their common as mud machines such as the spectrum and C64 as rare even when they are anything but.

I’ll wrap up here before I launch into a rant about how hard it is to find retro hardware here. Big thanks to any regular readers and commenters.

19
Oct
16

5th Anniversary and general update

Wow a year goes by so very fast! I have managed to get a lot done during this year such as continuing the photography and documentation of my various mother boards, and posts about MS-DOS games. However I’ve not been able to do everything I wanted, such as working on my home brew DOS game or completing the series I started about graphics library bench marking. This is mostly due to not having as much spare time as I used to. I’ve had to take up more domestic duties, especially with the kids going to school. So I’ve not been posting as often as I used to, often because I use the little spare time I have to rest. I’ve still managed roughly one or two posts a month.

As you might have guessed, I am still playing World of Warships and am still enjoying it. I also started playing Minecraft a few months ago after having played the pocket edition with my daughter. It has been a good game to play after all the work is done as it’s generally pretty relaxing to just do some mining, there is some interesting challenge in building automated farms, and it’s a good creative outlet when building what is essentially your home in game. Here’s a bunch of screenshots from around my world and base.

This slideshow requires JavaScript.

I’ve dabbled in playing World of Tanks, but I found I just couldn’t really enjoy the game all that much. I don’t really find it too pay-to-win, I just really didn’t enjoy the new player experience. Basically when you start to get into Tier 2 3 and 4 tanks you get totally nuked by people who have already got 100% crews with skills, equipment and game play experience. The grind to just upgrade your crew is insanely long, at the level I played you’d get the next tank in the line before getting 100% let alone any of the skills. I had plenty of games where I didn’t get to shoot anything because I’d get one-shot by someone I couldn’t see (and couldn’t know they spotted me or how). Because I essentially spontaneously exploded, I had no opportunity to learn what I did wrong. I tried playing artillery, but found that annoying, mostly because RNG meant that many of your shots regardless of aim didn’t count. Needless to say I didn’t have any fun, so I did what anyone would do, I stopped playing.

Content wise I’m getting near the end of my collection of mother boards, so I’ll probably fill its place with stuff that’s been on the back burner for a while. I had considered posting about Minecraft and World of Warships as I’ve been playing them when I get a chance and need to relax, but I didn’t feel they’d fit with what I usually do here, and there isn’t much I could really write about those games. I am still planning on doing Window 9x era games at some point, but they simply will take too much time at this point.

Thank you to anyone who reads, whether it is regularly or just once off.  I still enjoy writing, although I have significantly less time to do so.

30
Oct
15

4th Anniversary and site update

Recently (about 10 days ago) my blog turned 4 years old, which is amazing in many ways. Unfortunately many projects have simply stalled, mostly due to lack of time on my part. I’m still interested in them, but with my kids getting older and demands on my time getting larger it has been difficult finding time to do much. Lately it has even been hard maintaining a weekly post, which should fortunately improve now that the university semester is drawing to a close.

So what am I planning? Well not much in the way of changes, but I’ve got many projects that I’ve started and want to make some headway on again. Firstly I’ll be continuing the photography of my main board collection, although these posts take quite some time to research, photograph and write, they’ve been a good way to re-discover what I have sitting in boxes on the shelves. After I run out of main boards I might extend this to other hardware I have, although I don’t think I can write as much about something like an old hard disk.

The benchmark project is almost at the end, just that the final measurement on some 386 hardware has become problematic. See here for what happened. I wonder if it is just the particular machine which is the problem, but not having another functional 386 easily accessible makes this hard to determine. I also need to finish tidying up my workbench so I can work on it and future electronics projects.

The Micro-professor being one electronics project I really want to get into. I have a rough outline of a memory expansion in my mind, but I need to get some parts together and time to design, build and test. I couldn’t get the loading and saving working via the cassette interface and PC sound-card, so I thought I would include in the expansion design a way for an Arduino to take control of the bus and dump/load the memory of the machine.

Software wise I have a pile of projects I’d like to continue, but my home-brew platform game is probably the one I’m most interested in getting some work done. I intend on saving some more disk space by implementing Huffman coding to compress text I have stored on disk, but the bulk of the work required for the game is really designing and building levels and music. I have a nearly finished gwbasic game that needs some polish to complete, and similarly some level design. Making games is perhaps one of my favourite past times, although I don’t think they are of high enough quality to sell, I enjoy the process of coding, play testing, and designing.

Of course I will continue to write about old MS-DOS games, although I’ve covered most of everything I played as a kid. I like how colourful most games from this period are, many are also simple and easy to play in a limited time frame, which makes them appealing to someone with limited time like myself. In the future I’d like to start writing about the more modern games I play/own such as those from the Windows 95-98 era, but these will take a much larger time investment, mostly as the games are significantly larger.

Finally I’d like to thank anyone who has been reading, whether it’s just one page or if you happen to read more. I find it quite enjoyable to write these posts/articles even though I’m not really a great writer. It has also proven to be a good way to connect with other bloggers who have similar interests.

16
Jul
15

Photos from Home

I’m about to leave my parents place to head back home and back to work. I always quite enjoy the trip here to Narrabri and find it a much needed break from the stresses of every day life. Today I thought I’d share some of that with you in the form of photos I’ve taken over the years along with a description of what makes this place special to me.

Continue reading ‘Photos from Home’

23
Jun
15

Still Unpacking and Cleaning

I’m still in the process of unpacking and cleaning my old place, so no detailed post this week either. I don’t have the internet on at home yet so I don’t know how long I’ll be until I’m ready to do much, but things are starting to settle down and I should get a lot done in the coming weekend.

Until then here’s a link to an interesting video by Gemini (Kris Asick) about whether Doom is technically a Raycaster or not. It’s an interesting view, although rendering an 3d image is a difficult process to follow. Gemini has a web-show called Ancient DOS Games which is pretty cool, and develops games. Check out his web-site.

16
Jun
15

Moving House – again

Just a quick heads up that I’m presently moving house. I’ve done much of my packing and moving this weekend just gone, but it will take me a little while before I have my computer lab set back up for photography, gaming and experimentation. I’ll try to make a few DOS game posts if I have time, but I can’t make any promises and my server hosting the download section will be off-line until I’m able to set up a mirror or internet connection.




Blogs I Follow

Enter your email address to follow this blog and receive notifications of new posts by email.


Mister G Kids

A daily comic about real stuff little kids say in school. By Matt Gajdoš

Random Battles: my life long level grind

completing every RPG, ever.

Gough's Tech Zone

Reversing the mindless enslavement of humans by technology.

Retrocosm's Vintage Computing, Tech & Scale RC Blog

Random mutterings on retro computing, old technology, some new, plus radio controlled scale modelling.

ancientelectronics

retro computing and gaming plus a little more

Retrocomputing with 90's SPARC

21st-Century computing, the hard way

lazygamereviews

MS-DOS game reviews, retro ramblings and more...