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MicroMac, a Macintosh for under £5

axio.ms

171–180 of 180 posts

Re: MicroMac, a Macintosh for under £5

#171

How are these people finding VGA cables in the street :S I needed like 10 or so VGA cables recently for an art installation and asked everyone I could and nobody had any lying around... I ended up having to buy new ones which seems a shame considering how many are thrown away!

I usually source mine from thrift stores.

Re: MicroMac, a Macintosh for under £5

#172
post #78
post #68

Earlier quoted context omitted.

A hill I will die on is that tech products should just stop bundling cables, for anything, with the possible exception of unit-specific power adapters. A while back I purchased a KVM switch - it came with 3 DP cables, which went straight into my e-waste box. I've also seen office fit-outs where mountains of cables that came with monitors went straight from factory to landfill because they were the wrong length. I und…

> possible exception of unit-specific power adapters No. Unit-specific power adapters should not exist. Either put a USB-C or a 120v/240v AC connector on the device, depending on power requirements. It's really not that hard. Note: it must be connector, not a fixed cable. I.e. an IEC C8 or C14.

I'd add 8P8C for PoE to that list, but otherwise agreed.

Re: MicroMac, a Macintosh for under £5

#173
post #88
post #78

Earlier quoted context omitted.

> possible exception of unit-specific power adapters No. Unit-specific power adapters should not exist. Either put a USB-C or a 120v/240v AC connector on the device, depending on power requirements. It's really not that hard. Note: it must be connector, not a fixed cable. I.e. an IEC C8 or C14.

This might apply to (most) IT devices. But there are devices that require 24 V, or 48 V, or any other voltage that USB-C can't supply, and that for various reasons (space, EMI, possibly even compliance with some safety regulation) can't contain an integrated power supply unit from 120/230 V mains. Of course this should be an exception and most consumer devices can definitely work with the regular voltages and current…

> But there are devices that require 24 V, or 48 V, or any other voltage that USB-C can't supply, and that for various reasons (space, EMI, possibly even compliance with some safety regulation) can't contain an integrated power supply unit from 120/230 V mains.

Sounds like a job for Power-over-Ethernet :)

Re: MicroMac, a Macintosh for under £5

#174
post #125

Earlier quoted context omitted.

Nyet, comrade. She was at the front like some sort of living maidenhead while I leisurely rowed at the back with the entrenching tool that I kept in the car, one evening at an outdoor music festival somewhere in the Midwest. It was all very beautiful; the girl was beautiful, the sky was beautiful, the music was beautiful, and the place itself was beautiful; everything was approximately perfect. There was such a profo…

* figurehead (A maidenhead is quite a different thing.)

Yeah, copy that. Things like that happen when writing stories using a pocket supercomputer while standing in the shower.

Re: MicroMac, a Macintosh for under £5

#175
post #143

Earlier quoted context omitted.

Mine was pretty easy to fix - I was surprised how simple it was. IIRC, there's an inlet valve, a circulating/heater pump, and an exhaust pump.

Dishwashers, washing machines, dryers, threadmills, all have common issues and fairly simple fixes, if spare parts are available. I'm actually surprised there aren't general purpose boards, electric motors, heaters pumps etc out there that could be just swapped in. As long as the enclosure is in presentable state, that is

I found a place* that repairs appliance control boards. They replace the caps and relays and then reflow the whole thing. They give a 2-year warranty, which is 24 times what you get buying a new board. FedEx the board to them, they turn it around in a day and FedEx it back. We no longer dread the oven throwing errors at Thanksgiving, etc.

* Circuit Board Medics, but I understand there are others.

Re: MicroMac, a Macintosh for under £5

#176
post #26

I had a Saturday job at a computer shop when the Mac came out, and we got one as a demo. I remember just staring at the genius of those rounded corners in the corners of the screen, and thinking how beautiful it was that they'd thought of that.

In case you haven't read it - https://folklore.org/Round_Rects_Are_Everywhere.html

Desktop browser might be smoothing things over here, but I tried to load this on my android tablet and had to add www to get the domain to resolve.

Re: MicroMac, a Macintosh for under £5

#177
post #143

Earlier quoted context omitted.

Dishwashers, washing machines, dryers, threadmills, all have common issues and fairly simple fixes, if spare parts are available. I'm actually surprised there aren't general purpose boards, electric motors, heaters pumps etc out there that could be just swapped in. As long as the enclosure is in presentable state, that is

I recently came across a slew of replacement boards that basically completely take over your washing machine and runs it. Some Chinese generic stuff that is meant to install in any machine missing its original control board.

The Chinese seem to be pumping a lot of those type of things out lately. I have recently found a driver for quite niche of CRT.

Re: MicroMac, a Macintosh for under £5

#178
post #38

Earlier quoted context omitted.

You would be surprised how much trash there is in the city around us, that you suddenly start noticing when you have a diy project. Let me share you some moments of my own with you. I was leaving university campus with my buddies, talking about building magnetic card reader to check contents of my campus library card. Just as I was explaining magnetic heads to one of the guys I see a random cassette player few meters…

> Mid sentence I stop, grab and smash the radio open on the curb, pull out the magnetic head and continue talking about the said magnetic head. Guys were bewildered. In what world is this acceptable to take some trash and make the trash situation worse by bashing it apart in the street?

Wasn't much worse though, I cracked it open in two main parts (front face fell off, exposing cassette decks), and put it back on pile. You couldn't tell a difference. I would not make a bigger mess than it already is.

Re: MicroMac, a Macintosh for under £5

#179
post #157
post #38

Earlier quoted context omitted.

You would be surprised how much trash there is in the city around us, that you suddenly start noticing when you have a diy project. Let me share you some moments of my own with you. I was leaving university campus with my buddies, talking about building magnetic card reader to check contents of my campus library card. Just as I was explaining magnetic heads to one of the guys I see a random cassette player few meters…

This is becoming less common among electro-trash as SMD rules the day instead of larger, more discrete, more easy-to-separate components. For example, try pulling anything useful - camera lens, buttons, memory, ICs, anything - from any mobile phone tossed away.

Yea, most of tech is not human size anymore. Still, some things can be repurposed in high tech workshop with a lot of skill. For example Optical Pickup Unit from Blu ray for laser scanning microscope.

Re: MicroMac, a Macintosh for under £5

#180
post #25

This is a really impressive project! It was a fun read. Thanks for sharing! I like this writing style. > As an aside, I try to create a dual-target build for all my embedded projects, with a native host build for rapid prototyping/debugging I find myself doing the same thing on my embedded projects, including at my job. I actually find myself using the PC build much more frequently than the hardware for my day-to-day…

How would you go about setting this up? Do you mock out low level calls or are you running some sort of emulator?

Sorry, I somehow missed your comment until now. Didn't get any notifications. I tend to do it more like what you first said, mocking low-level calls.

I typically put all hardware-specific code for one platform into its own directory. Then I can have multiple directories for different hardware implementations, like MCU #1, MCU #2, and PC. I just implement the same API in all three. It's basically just a HAL. Each build only compiles one of those directories -- the one that matches the architecture I'm building for.

For example I might have a function that does an SPI transaction. On the two hardware builds it will actually communicate with the SPI peripheral in the MCU, but on the PC build it will talk to something I've written to pretend to be the SPI device. So it does take a little bit of up-front work writing code that pretends to be the various devices. In some ways you could call that an emulator, but not in the way you were asking I think.

You can make it as simple or complex as you want to. You could do a full-fledged object-oriented SPI class in C++ (or "class" in C), with different class implementations for different hardware builds. Or you could just make a single function that does SPI stuff and reimplement it for each hardware build.

In one case I have a Qt GUI that pretends to be the UI for the device so the PC hardware-specific code ends up providing its own main() and runs the actual shared codebase in a separate thread. So that particular codebase has a provision to rename the shared main() to not actually be main() on the PC build so it plays nicely with Qt needing to actually provide main().

One downside is you won't catch certain bugs on the PC. There have been a few bugs that slipped past because the hardware build was 32-bit but my PC build was 64-bit for example. But those errors are fairly rare. I probably should be doing the PC build as 32-bit to make it more similar anyway. Still, it wouldn't catch every little problem that might pop up on hardware. It definitely accelerates my productivity though!

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