Tim Mackinnon improved everybody’s #productivity by #pair-programming with them.
who’s hiring, September 02023
#GCC for i386 has function attributes including fastcall, no_caller_saved_registers, and interrupt
the #RISC-V calling-convention #PDF: x2 (sp), x8 (fp/s0), x9 (s1), and x18–27 (s2–11) are call-preserved; x3 is the global pointer gp, which you need to preserve even for callees; and x4 is the thread pointer tp, which likewise. But x1 (ra/lr), x5–7 (t0–2), x10–17 (a0–7), and x28–31 (t3–6) are call-clobbered. a0–1 are return-value registers, making the same mistake as in the ARM calling convention. The stack pointer is always kept 16-byte (!!) aligned. Note that most RVC instructions can only access x8–x15 because their register fields are 3 bits; those are the call-preserved fp/s0 and s1 and the call-clobbered x10–15 (a0–5).
A #one-bit (?) computer driven by a state machine in EEPROM #hardware; the I/O registers and next-state register are clocked on opposite phases of the clock, and the clock goes to the A0 address line on the EEPROM, so different 8-bit words from the EEPROM drive those two registers. He’s using 74(LS?)574s for the state registers, a 74LS151 for input multiplexing, a 74LS259 for output multiplexing, and a 74(LS?)04 for inverting the clock and reset.
Jeff Laughton’s original page on the #one-bit #hardware design with the clock line running into the ROM address line. In his case he used 74C374 registers for the state and CD4000 chips for the I/O, and wrapped two of the CD4099 output lines to the CD4051 input multiplexer to give it two bits of RAM. #electronics
Here’s how the #Linux kernel generates stack backtraces on #RISC-V by walking a chain of stack frames linked by frame pointers. With alloca() and variable-length arrays, the stack pointer alone isn’t enough to find your local variables.
In addition to the #one-bit computer, Laughton also built #hardware to add 24-bit bank-switching to a #6502, giving it a 16-megabyte memory space, with four 8-bit bank registers in a coprocessor. The K0 bank register is used for all code fetches and, by default, data fetches, but there are “segment prefix” instructions that activate K1 or K2 for a single instruction, and K3 is used for far jumps and far calls. #electronics
Rue Mohr asked ChatGPT to draw a dragon, and this is the SVG it generated. #neural-networks
#Faried asked Bard to ‘write a song like “temple of love” by “sisters of mercy” except about risc v’ #neural-networks
#satire “Why do all these homosexuals keep sucking my cock?”
distributed acyclic #garbage-collection in #CapTP for #capability-systems
“#Apple’s Decision to Kill Its CSAM Photo-Scanning Tool Sparks Fresh Controversy: Scanning every user’s privately stored iCloud data would create new threat vectors for data thieves to find and exploit. It would also inject the potential for a slippery slope of unintended consequences. Scanning for one type of content, for instance, opens the door for bulk surveillance and could create a desire to search other encrypted messaging systems across content types. (...) We decided to not proceed with the proposal for a hybrid client-server approach to CSAM detection for iCloud Photos from a few years ago. We concluded it was not practically possible to implement without ultimately imperiling the security and privacy of our users.” #USA #politics #censorship #privacy #security
discussion of #Apple’s #privacy decision to not scan people’s phones
holy shit, the Timex m851 watch came with an SDK, a 42×11 LCD, 48KiB of ROM, 2KiB of RAM, and a three-year battery life
notes on #performance optimization: most aren’t worth it, unlike in Shenzhen IO
Simon Tatham’s notes on #coroutines and #concurrency for state machines
apparently #VexRiscv and also #PicoRV32 supports the #iCE40 UP5K #hardware multipliers now (there are 8) because #Yosys can infer them as of last year
#fiction from Greg Egan about cosmology
Cliff Click’s #PDF dissertation #paper on optimizing #compilers from 01995, which #moon-child says is the basis for HotSpot.
the #documentation for #Scheme #performance in #Racket
wow, movie makeup prosthetics with foam latex and silicone are astoundingly good. Animatronic lip-sync‽ Also, pneumatically powered puppets.
