Dave got the Samson StudioDock 4i USB speakers for editing the blog. What's inside?

The Dulmont Magnum "Kookaburra" from 1983 is the only laptop to have even been design and made in Australia, as well as being one of the world's first "clamshell" laptop designs. Dave tears down this obscure retro classic based on the equally rare 80186. Brochure: http://www.eevblog.com/files/Kookaburra.pdf UPDATE: John Blair has responded about this video: Dave Thanks so much for sending this along; I got a huge kick out of it. I can answer some of the questions you raised in the video: (*) You're right there was no removable R/W storage in 'laptop' mode; the 'disks' that MSDOS saw were implemented in RAM. You added removable storage by connecting the dual floppy drives via the parallel connector that you noted on the back. (*) I wasn’t the original designer; I was brought in to run the software team (once Barry had the prototype hardware up), which I did throughout. Chris T was brought on later to run the hardware team; he and I worked together. Terry Crews was originally hired before me as engineering manager before me but it was immediately clear that he had no clue what he was doing in that role; they made him marketing manager, where he was responsible for those remarkable ads that you cited. (*) The parallel port wasn’t really custom – was a standard configuration for that era. (*) The 15 way ports were serial ports for printers et al, as you note later (*) The RCA connector was a video port, as you note later. (*) You're right that the ROMs contained MS-DOS – we actually had to modify MSDOS so that it ran from ROM, which was hard to do; lots of Gatesian self modifying code. I don’t believe anyone else got that to work, but it had a major benefit, in freeing up all the SRAM for stack and RAM disk (*) 6:46 is classic, but in Barry's defence the model you have there is some weird prototype; hence all the kludges and the handwritten labels. (*) The 80186 was NMOS, as you note. That was kind of the miracle here. Barry and I didn’t want CMOS because they were so so slow. But NMOS consumed a lot of power. The solution was to mod MSDOS so that the CPU and all of its support could be powered off between keystrokes; each time you hit a key, the 186 would come up from cold, and transparently reenter the OS. As you note. Gave us all of the performance of a PC and great battery life. We were much faster than 8088 desktops of the time. (*) You Got It Working!!!! That’s so great! Congratulations. (*) Drive B wasn’t ready because it was the plug in ROM (*) The SRAM kept alive all the time – that’s where the RAM Disks were (*) The tirade at the end isn’t really fair – this was a prototype between the Magnum and the Kookaburra . None of the points you make about removable store, video etc are correct – remember that when you plugged in a video monitor and disks, this was the fastest desktop PC of the time, that you could also take on the road. Forum: http://www.eevblog.com/forum/blog/eevblog-949-vintage-australian-made-laptop-teardown/msg1080508/#msg1080508 EEVblog Main Web Site: http://www.eevblog.com The 2nd EEVblog Channel: http://www.youtube.com/EEVblog2 Support the EEVblog through Patreon! http://www.patreon.com/eevblog EEVblog Amazon Store (Dave gets a cut): http://astore.amazon.com/eevblogstore-20 T-Shirts: http://teespring.com/stores/eevblog

http://www.onsemi.com/pub/Collateral/MC34262-D.PDF http://www.youtube.com/watch?v=bX8IIjf15qY This was supposed to be a small side piece in the Manson PSU Teardown, but it was almost 10 minutes, so I decided to separate it out to keep the teardown as short as possible. You should watch the PSU teardown to get the context of this where the chip is used.

In this tutorial Dave explains how to precisely measure and calculate the remaining (or wasted) energy capacity in a battery using the graphical analysis technique using a spreadsheet. The differences between constant power and constant current loads and when to use them is discussed. Also, the importance of ESR and measuring the battery voltage under load is demonstrated. This is a particularly relevant to the Batteriser product and proof is provided that shows that even over the entire current range, the wasted energy in a battery can be no better than a few 10's of percent for a 1.1V cutout voltage. Blowing the batteriser claim of 80% wasted energy out of the water. Forum: http://www.eevblog.com/forum/blog/eevblog-772-how-to-calculate-wasted-battery-capacity/ All of my battery related videos are here: https://www.youtube.com/playlist?list=PLvOlSehNtuHtj5Ubhx7govoBfNkyUO4Pp DIY Constant current load: https://www.youtube.com/watch?v=8xX2SVcItOA Battery Capacity Tutorial: https://www.youtube.com/watch?v=R8hTQXqURB4 AA Battery Capacity Measurement: https://www.youtube.com/watch?v=uT4hKd66UY4 Batteriser Debunking Video: https://www.youtube.com/watch?v=4iEshd6izgk LiPo Battery Discharging: https://www.youtube.com/watch?v=ln8Mlz4NsW8 EEVblog Main Web Site: http://www.eevblog.com The 2nd EEVblog Channel: http://www.youtube.com/EEVblog2 Support the EEVblog through Patreon! http://www.patreon.com/eevblog EEVblog Amazon Store (Dave gets a cut): http://astore.amazon.com/eevblogstore-20 T-Shirts: http://teespring.com/stores/eevblog Donations: http://www.eevblog.com/donations/ Projects: http://www.eevblog.com/projects/ Electronics Info Wiki: http://www.eevblog.com/wiki/