Charles U. Farley @freakazoid@retro.social

Another challenge with analog signals is that they're very difficult to multiplex, and once you've done the work to implement, say, time division or frequency division multiplexing, now your circuit draws a similar amount of power to a digital one. So something like this makes the most sense for a very local control loop where the control device is near both the sensors and the actuators.

And even though the world is analog, most off-the-shelf sensors output a digital signal, usually either serial (SPI or I2C) or PWM. And the servos used to control robots are usually also digitally controlled. The problem is that analog signals are subject to noise, require a reference voltage, and analog components are way fiddlier to deal with. This is why class D amplifiers are taking over the world even when the source signal is analog.

Memristors are super cool. These folks have implemented an entirely analog control loop using them. I think their results are being a bit over-hyped in the article, though.

"Specifically, cycle time is reduced from 3,034 microseconds to just 6 microseconds."

500x seems like a lot, but one could easily get the cycle down to 6us using a local, dedicated microcontroller. It would probably use more power, though.

https://spectrum.ieee.org/automaton/robotics/robotics-hardware/braininspired-robot-controller-uses-memristors-for-fast-efficient-movement

@xj9 Why does your profile say you're a bot?

Fortunately, there is a #CPM utility to re-flash the ROM, so I won't need to keep putting the z80ctrl board back in if I want to update it. Which is good, because it's really hard to get these boards out without bending the pins.

Aside from running old Coleco games, I also want to try out various BASICs. But before I do that I want to wean myself off of using the z80ctrl board to increase my level of retro purity. Or at least plausibility. I still need the dual clock board to even boot without the z80ctrl, and then I'll need to assemble the IDE controller to be able to read and write files.

2/

So far I've run some demos on the #rc2014 that use the TMS9918 video card, and I've played around with #CPM. I've managed to boot a couple #Coleco games (Donkey Kong, Galaxian) but I can't start them until I finish building the game controller board, which has buttons to emulate the keypad on the Coleco controller. And I accidentally left the game controller board out of my big parts order. I placed a separate order yesterday, so the parts should arrive later in the week.

1/

I will be running this on an #RC2014, not a RetroBrew. I have the 512k RAM/512k ROM board and the dual serial board built, so I just need the clock board. I can program the flash using the z80ctrl, but the z80ctrl doesn't support actually running RomWBW, so then I have to take it out and put in the dual serial and clock boards to actually run it.

"Typically, a computer will contain a small ROM that contains the BIOS (Basic Input/Output System) functions as well as code to start the system by booting an operating system from a disk. Since the #RetroBrew Computers Projects provide a large ROM space, #RomWBW provides a much more comprehensive software package. In fact, it is entirely possible to run a fully functioning RetroBrew Computers System with nothing but the ROM."

Just what I want in a computer.

https://github.com/wwarthen/RomWBW

Should have done more research before picking this #VFD up on eBay. It's just the display with no driver board, and there doesn't appear to be any way to get a driver board for it.

Anyone want a Noritake 4045A VFD? Yours for the cost of shipping. I'd hate to throw it out, but I don't see putting together my own driver for it unless someone can point me at an example project or something.

#retrohousewares

My big Digi-Key order arrived, so I started out with the #Z80 SIO/2 (dual serial) board for the #RC2014. And then when I was looking for the actual SIO/2 chip to put it in the socket, I remembered I had had to order it on eBay and it hasn't arrived yet :-/

Rule 34a: if it exists, there are ASMR videos of it.

I'm an idiot for having done so much soldering without making ASMR videos of it.

Really tempted to build this 8088 PC, because there's a lot more software for #DOS as well as off the shelf hardware, and unlike #CPM I actually used it as a kid. But since building a PC from scratch is way harder, the DOS community is a lot more about #retrocomputing than #homebrewcomputer .

https://www.smbaker.com/building-an-xi-8088-pc