Notices by Studio 8502 :verified: (mos_8502@oldbytes.space)

I have just read the Georgia indictment of Donald Trump and nearly 20 other people.

Holy fuck. It’s a RICO case.

@thomasfuchs Most of it, yeah. The XNU kernel is kind of a hybrid of Mach and some BSD stuff and a bunch of Apple original code.

@deutrino Put them both in a steel cage with a lump hammer each. Last man alive wins all the other’s wealth, minus 45% tax.

These were actually very popular for use as cocaine spoons. That's not an urban legend, it's historical fact. They're actually kind of collectible now.

#trivia #americana #drugs

Neurotypicals stop letting the goblins in your head decide what I mean and make you argue with that instead of what the fuck I said challenge: Impossible

Firmware updates for the Turaco SBC will not be complicated. You will simply put an updated firmware.bin file on your SD card, and boot it. The machine will do the rest -- writing the firmware.bin to the internal ROM of the EZ80F91 CPU, which includes the bitstream for the FPGA, which in this implementation is an SPI slave, programmed at boot time by the CPU over SPI.

The maximum bitstream size for the iCE40UP5K, according to the documentation, is 104,161 bytes, or ~102KB; that is how much of the on-chip 256KB of flash ROM on the EZ80F91 must be devoted to holding the VERA bitstream. That leaves 154KB for a system ROM. The code that lives in there has to know how to do several things:

• Load a file from SD to RAM
• Run a program from RAM
• Contain system-specific ROM functions for talking to the various bits of hardware, including programming the FPGA over SPI
• Check the SD card for an auto-boot program, and boot it if found
• Boot to a serial monitor if all else fails

At boot time, the CPU will do what the ROM says to do, which is first check for a firmware.bin file, which is a binary program which runs in RAM and re-programs the ROM; if that is found, then load and run it. Otherwise, check for a bootable OS, and boot it if found. Otherwise, boot to the ROM monitor talking over the serial port.

I'm thinking the most neutral way to handle operating systems is to do it the way old school Z80 systems did it, and write the "boot sector" for the OS to the first sectors of the SD card. A FAT32/ExFAT SD card still has an MBR partition table; the MBR can as easily contain Z80 boot code as 8086 boot code.

Getting 2.5GB/sec sequential writes on the M.2 RAID0, which seems somewhere near correct, given that the motherboard is old and there's software RAID and LVM involved. Sequential reads come in at 3.0GB/sec, which also makes sense.

Me: "I'm hungry."

Fast Food: "Here's sugar and grease, only $60!"

My Brain: "Sounds fair."

Also me: "I want this retrocomputing toy."

Seller: "Here you go, only $60!"

Also My Brain: "Wait, we better talk to our accountant about this."

Why?

COMING NEXT WEEK: The J-CIA is finally shipping to regular folks!

https://retro8bitshop.com/product/j-cia64/?fbclid=IwAR3BCqSBv_AlSPH5-XD3LZJKsYDvOSD7ZFownOlYLlS49fSlpWO1zU-WQnE

@thomasfuchs @gsuberland I mean, that's what, 72.6 watts?

Which do you think is smarter when using an ATX power supply to power a 3.3V system: Using the 3.3V rail off the PSU directly, or using the 5V rail and a regulator to power it?

@gsuberland I always fuse my power supply systems, yeah. Going from 12V to 3.3V and 1.2V, that's going to drop a lot of heat with a linear regulator. Switching is better here, yeah?

@gsuberland So what do you think for the switching DC-DC converter, 12V nominal input, 3.3V output, rated for what, 10A?

@gsuberland Currently it's set at 500mA peak per expansion card -- do you think it should be a full 1000mA?

@gsuberland So, something like this https://www.mouser.ca/datasheet/2/1458/DS6228ABC_03-3104914.pdf for the 12V->3.3V, and then a small ~100mA LDO running off of that switching reg's output for the 1.2V line?

@gsuberland Looking at an El Cheapo $30 power supply off Amazon and it claims to have 22A on the 3.3V rail.

Today's #retrocomputing whatthefuckery is brought to you by Facebook, the letters 𒉘, 𑪵, and 𓃂, the number ꧓, and viewers like you.

I legitimately felt betrayed when QNX for the desktop was abandoned. It was so cool.