Monday, June 09, 2014

More computer rescuing. A Macintosh SE

A bunch of various sparcs, more about them soon. But I got this old thing:

After some boot disk hunting I got to boot into System 7.1. Memory have been upgraded to a nice 2.5Mb.

Thursday, June 05, 2014

Computer rescue! SGI Indy, SS20, Ultra 1 and SunBlade 150

Hmm, don't know if I've ever blogged about my collecting hobby ? Well, I do. Computers. Surprise. Have about a 120 or so.

A couple if weeks ago I struck gold so to say. Åbo Akademi ICT deparment needs to move as the building they are located in needs to be renovated. They have stashed quite nicely a lot of old computers. I had a chance to loot trough the stuff before getting trashed.

There where quite a lot of stuff, mostly just old PC junk. But I did find something fun:

Oh, and I'm going tomorrow to take another look, there are a least 4 SunBlade 100 workstations waiting for me.

Tuesday, May 20, 2014

How to transfer things to a computer when the only connection you have is serial console ?

I was reading something and suddenly got a flashback to when I was playing with an old IBM RS6000/320 I got many years ago. Getting it up and running was a fun exercise in patience, installing AIX 3.2.5 (I think) from tapes. It took a couple of hours. And I had to do it twice if I remember correctly as the HD I had was too small.

Anyway, when AIX was up and running the next problem was getting a bit of basic software into it like gcc and ssh. That should be easy, right ? Just use scp.. oh wait, AIX 3.2.5, that is kinda old. Even at the time (2000), very, very old (AIX 3.2 was release in 1992). So no nice tools to use. And I didn't have suitable network cabling for it at home at the time either, so no use of any primitive networking tools. The only connection I had was the slow serial console.

The simple answer: uuencode and uudecode

And that reminds me, need to check if it still runs after all these years.

Monday, May 19, 2014

CAN bus, chips and usb adapter

I got my CAN bus chip, a couple of MCP2515 controllers and and MCP2551 transceivers and also the required boilerplate components or whatever you call them in the hardware world :)

MCP2515 and MCP2551
Also I'm waiting for a USB2CAN dongle by 8devices (ordered from EXP Tech), it should arrive today if DHL does its thing on time.

The MCP2515 and MCP2551 seem to be the most common chips used by DYI/Arduino/etc users, not that surprising as there aren't that many breadboard friendly CAN chips available. For example the is a new controller available by Microchip, the MCP25625 with integrated CAN bus tranceiver, but it is not trough hole friendly as it is only available in SSOP-28L and 6x6 QFN-28L. But I wouldn't be surprised if someone will offer breakoutboards soon.

But one new chip is quite nice for users of 3.3V systems, for example the Arduino Due that has 2 CAN busses included in the Atmel SAM3X8E ARM Cortex-M3 CPU but no transceiver. The MCP2562 transceiver, it has separate voltages for the IO and CAN bus part, so you can plug it directly into any low-voltage device without the need of any level converters. I need to get myself some of those for my Due as I would prefer as little extra components as possible.

Saturday, May 10, 2014

Y-Radio problems

Well, YLE did the stupidest thing ever around 1 of May. They removed their shoutcast streams and now offer only RTSP and HLS streams. Using AAC. And guess what Y-Radio uses? That is right, the shoutcast streams.

And the RTSP streams, that work perfectly fine on desktop, fail on Jolla as various gstreamer modules are missing won't play the streams properly.

And you are not allowed to add gstreamer modules for harbour releases.


I'm trying to figure out something, but for now Y-Radio is broken. Sorry about that.

Friday, April 25, 2014

Getting on the CAN bus

I co-worker from waaay back (199?) contacted me a while ago about helping out with some issues he had with a linux system that talks with a CAN bus. A very interesting system. But I won't go into specifics here on that point.

Anyway, CAN bus. Most will probably think OBD-II, cars and ELM327, understandable as that is what it was designed for. And that was just about all I did know about it myself too. Researching into it some more was very enlightening and I got some cool ideas on how to use CAN for one of my own little forever projects.

Now, CAN bus is quite simple, two wires, differential. All you need is a transceiver, a controller and something to tie that into your computer, USB, RS232, PCI, etc. Some Linux friendly and cheap boards even have CAN bus integrated in their SoC. And there are some easy to interface SPI controllers that you can use with your favourite microcontroller.

What makes it really interesting is that most of the low-level stuff is handled on-chip. Software does not need to care about timings, arbitration, bit-stuffing, CRC and all that. It is all on the chip. And you have a wide choice of bandwidth/length options. Need to connect that sensor a 100 meters away ? No problem. And thanks to being designed for hostile environments it should work over just about any two wires, or so I've heard.

There are some limits of course. Maximum data packet size is a whooping 8 bytes. And messages have only have a message ID, no sender or receiver ID. So the network is a 1:N broadcast network. But still, that is quite OK for a sensor network.

I ordered a couple of MCP2515 and MCP2551 chips and I hope I have some time do play with them soon.

Y-Radio updated, new icon and Facebook page!

I finally got Y-Radio update in harbour, already a couple of weeks ago (QA approved April 8th). New features include:
  • All available YLE Radio channels now available and nicely grouped
  • For channels that offer it, program information (Note: this uses the undocumented API still, so it might have issues from time to time)
  •  Channel information with quick links to various on-line service the radio channel offer (Twitter, YouTube, etc)
  • Preliminary translations to Finnish and Swedish
  • Major internal changes
  • And Y-Radio is now on Facebook
Channel list
Program details

Program information
Also a very helpfull Jolla community member offered to create a much nicer icon for the application. This version does not use it yet, but the next update will have it. But take a look at this, awesome isn't it ?!
New Y-Radio icon