Category Archives: Tech

Technology in general

Resurrecting the past

Posted on by

Lately I’ve been digging into more of my retro collection to repair and preserve some of these systems and components. One of the systems I’ve put a fair amount of time into was the first motherboard I bought. It was a humble system, even by the standards of the day, barely exceeding the performance of the previous generation, but it was really the beginning… the first system I assembled from (mostly) new parts. My first 2 computers were an 8088 (XT) I cobbled together from spare parts and an 80286 that I got from a friend and some additional used parts from the 8088 and elsewhere. The system board I chose to create this new computer from was an Eteq 486SLC at 33Mhz. It was powered by a Texas Instruments TX486SLC/E-33MAB CPU, a licensed copy of the Cyrix 486SLC. This was a low power variant of the Cyrix 486 CPU intended for use in mobile or embedded applications. (like Intel’s SX compared with the DX 486 CPUs, or DLC in the case of Cyrix) In a desktop the 486SLC was competent, but was not fast by any means, only performing slightly faster than a i386DX CPU at 40Mhz. (mostly due to the fact that the Cyrix/TI design had a small amount of onboard cache memory, but also close because the SLC/SX CPUs only have a 16-bit external bus which slows down I/O)

Eteq 486SLC board with corrosion, before cleaning
corrosion visible on the board before cleaning

Like many systems of the era, this board was equipped with a Varta NiMH rechargeable battery soldered permanently to the board. Also like many of these systems, over time the battery leaked and began corroding the conductive metals near the area. I had previously removed the battery and scrubbed some of these parts

with IPA and a toothbrush, but it hadn’t gotten a lot of the corrosion off. I decided to see if a bath in white vinegar would stop the corrosion and sure enough, it neutralized and broke it up. I repeated this several times until there were few if any remains of the corrosion visible. I had also removed the power and keyboard connectors from the board and given them a vinegar bath as well. (I had also removed all of the socketed chips and checked them for corrosion ahead of time) With the corrosion eliminated, I washed the board with tap water in the sink and set it up to dry for several days. (I also helped it along by turning it upside down and spraying it with compressed air)

Once I was sure the board was completely dry, I placed all of the chips back in their sockets and soldered the keyboard and power connectors back onto the board. While I had to fiddle with the hardware, I was able to get the system to POST after a few tries. The next problem I ran into was

corrosion removed from the board

the BIOS and it’s lack of support for large drives. I had purchased some IDE to CF adapters to allow me to boot from a Compact Flash card, but the 8GB cards I selected were too large. I’d recently seen a video about another retro enthusiast who had been able to use a network card with a custom boot ROM that might be able to solve this issue. While restoring my old 286, I built a complete 8-bit ISA controller using this same software (XTIDE) and thought I’d give this a try. I also happened to have the original EPROM for the Eteq 486SLC (which I’d replaced because it got corrupted… that’s a story for another time) and was able to successfully erase and re-write the chip with the XTIDE firmware. This got me further, but the system still seems to have some translation issues with the Winbond multi-io card I’m using. Eventually, I imaged the card with one I’d taken of an identical card from another system and that got it booting.

Eteq 486SLC with ALU and RAM populated

So, time to run some benchmarks and see what the system can do! As I suspected though, the system was pretty modest. As I mentioned earlier, the system only performed a little better than a i386-DX40. This isn’t so bad considering the design. You have to remember, at the time small jumps in processor frequency provided measurable performance increases. While the Cyrix-designed chip was a little slower and had an I/O bus half the size of 386, it had a more efficient design and onboard cache that helped it perform much better.

Also helping this system is a math co-processor made by IIT, the XC87SLC-33. This chip was effectively a recycled 80387 compatible design IIT had been pumping out since the 386 days. It’s performance is modest, but it was cheap and that made it attractive as a poor college

speedsys results

student. The Norton SpeedSys benchmark shown above demonstrates just how modest this system was. Looking at some similar reports for i486-DX266 CPUs, this is a little less than half the speed in just about every area. Because I’m curious, I’ll probably drop my Cyrix 486DX2-66 into a compatible motherboard and see how they compare. This system isn’t fast and it’s not all that exciting, but I’m glad I saved it from rotting away for good. Perhaps one of these days I’ll find a baby AT case and build it up into a complete system again.

Liquid metal robot is anything but

Posted on by

Recently the online magazine NewScientist published an article about a “Metal robot [that] can melt its way out of tight spaces to escape.” This sounds pretty amazing, but when you start to read into the article and watch the included video it becomes clear that the story is little more than clickbait.

The “robot” depicted is nothing more than combination of metals, mostly gallium that the scientists manipulate with a magnetic field. It’s an inert blob of material molded into the shape of a lego minifig, and that’s as close to a robot as it’s ever going to get. The article is clearly trying to relate to a certain movie about murderous cyborgs from the future. Don’t worry though, we’re not in any danger.

Calling this object a robot would be about the same as calling a ball bearing moved through a maze with a magnet, a maze-solving robot. The worst part of the video comes at the end when there’s a jump cut. We see it jump from the melted remains of the “robot” outside the cage and some bits still sticking to the bars of it’s cage where it passed through, to a fully re-formed figure standing in front of the cage.

They weren’t able to manipulate it into doing this, rather someone cleaned up the melted bits, shoved them back into the mold and reset the scene. If the material were to somehow be able to automatically return to it’s previous form that might be fairly innovative, but that’s not the case here. It’s simply a lump of metal with a low melting point that can be warmed up by current induced via magnetic fields penetrating it. (ie: inductive heating)

The definition of a robot is essentially an automated machine that can execute specific tasks with little or no human intervention. As much as the creators and writer want this to be a robot, it’s not.

Is Tesla potentially putting the public at risk with it’s cost-cutting strategy?

Posted on by

I’ve made no attempt to hide the fact that I’m not a fan of Tesla. It was never about the technology, but rather their business practices and the way they treat their customers. However, that may be about to change with what I would consider to be a penny wise, but pound foolish decision to remove radar and ultrasonic sensors from it’s vehicles.

In a report from Electrek, Tesla is basically saying that they’re going all-in on computer vision and dropping other sensors with the laughable justification that it’s how humans navigate. Considering the potential consequences, perhaps laughable isn’t the right word.

One of the features that impressed me the most about Tesla’s early self-driving feature was the integration of radar data. A perfect example of this can be found in this 2016 video of a Tesla detecting a vehicle several cars ahead that was moving slowly/braking and was able to avoid an accident. You can’t see the vehicle ahead as it’s completely obscured, but the Tesla radar could. Can a Tesla camera system do the same? Maybe, but I’m not sure I’d want to trust an autopilot system without radar. (or some other form of beyond visual spectrum object detection)

Tesla’s track record with self-driving cars hasn’t exactly been fool-proof either. (even with the additional sensors) I’ve been in Teslas that have had difficulty in daylight with the painted lines of the road. There have also been numerous incidents reported where autopilot didn’t see a crossing/oncoming vehicle resulting in fatalities. Beta testing software features is fine for the consumer smartphone and computer industries, but it shouldn’t be something that happens in cars on public roads with safety-critical systems.

Tesla does state in their announcement that “at this time, [they] do not plan to remove the functionality of ultrasonic sensors in [their] existing fleet.” Hopefully the same is true for the radar sensors as well. This appears to be targeted at new production models only with models 3 and Y, and later the S and X.

This Reuters article from early June explains some of the details of why a camera-only system could be less safe than one with additional radar sensors. Tesla may think they’re saving (making) money removing the sensors and making development easier for themselves, but not tackling the more difficult problem of integrating different sensors leaves gaps that may put people’s lives at risk.

Update 12/2022: Drivers of new vision only Tesla models already running into problems, some features not yet available

Update 12/16/2022: Tesla appears to be reversing course and bringing radar back based on FCC filing. Elektrek quoted the same tesla filing indicating Tesla would be marketing a new HD radar in mid-January of 2023. This is good news for potential new buyers and potentially for improvements in FSD, but what about those who bought the stripped down versions? If I were one of those customers, I wouldn’t be too happy.