General Development Archive

Visible Lisp Computer

The Visible Lisp Computer is a Lisp interpreter that displays the contents of the Lisp workspace on an OLED display, so you can see program execution and garbage collection in real time. It’s a special version of my uLisp interpreter for ARM boards, designed to run on an Adafruit ItsyBitsy M0, or an ATSAMD21E on a prototyping board, interfaced to an I2C OLED display. If I knew what any of this meant, you’d find a few words about this here. Sadly, I don’t know what any of this means.

Flutter looks good, but is painful. Here are my frustrations with it.

From the community to the 3rd party libraries, it looks Flutter is lot closer to Javascript than Android. Javascript, however, isn’t shy of moving faster while Flutter is still deciding what they want to be. Keep compatibility even if it creates confusion? Check. A lot of libraries with dubious quality that are just created and dropped? Check. I want to like it, but Flutter currently doesn’t want to like me. Maybe they are are short in personnel and needs to double their team? Maybe they need to just re-organize and prioritise better? Only they know. Not being a programmer in any way, shape, or form, articles such as these are always difficult to gauge – are they truthful? Factual? Emotional? My-way-or-the-highway? I’m posting it anyway since I’m sure many of you have a far better grasp on this than I do.

Jupiter: a RISC-V assembler and runtime simulator

Jupiter is an open source and education-oriented RISC-V assembler and runtime simulator. It is written in Java 11 and capable of simulate all the instructions of the base integer ISA (I extension) plus the M and F extensions (RV32IMF), including all the pseudo-instructions described in the user-level instruction set manual. It was developed taking into account that it could be used in various courses such as: Computer Architecture, Compilers and Assembly Programming.

Fast software, the best software

I love fast software. That is, software speedy both in function and interface. Software with minimal to no lag between wanting to activate or manipulate something and the thing happening. Lightness. Software that’s speedy usually means it’s focused. Like a good tool, it often means that it’s simple, but that’s not necessarily true. Speed in software is probably the most valuable, least valued asset. To me, speedy software is the difference between an application smoothly integrating into your life, and one called upon with great reluctance. Fastness in software is like great margins in a book — makes you smile without necessarily knowing why. Nothing to add.

Files are fraught with peril

In this talk, we’re going to look at how file systems differ from each other and other issues we might encounter when writing to files. We’re going to look at the file “stack” starting at the top with the file API, which we’ll see is nearly impossible to use correctly and that supporting multiple filesystems without corrupting data is much harder than supporting a single filesystem; move down to the filesystem, which we’ll see has serious bugs that cause data loss and data corruption; and then we’ll look at disks and see that disks can easily corrupt data at a rate five million times greater than claimed in vendor datasheets. Deeply technical, but well-written and pleasant to read.

Pete’s QBasic site

QBasic lives! QBasic is an old-school, vintage programming language that was designed for beginners. QBasic ran on MS-DOS, and was a more advanced version of BASIC. QB was a lot of people’s first foray into programming (particularly those of us who grew up in the ‘80s and ‘90s). Therefore, a lot of people look back at QBasic with nostalgia. QBasic is one of the very few programming languages I actually ever even used – back when i was a very young kid – so I do have some faint nostalgia for it. Great to see such a dedicated community keeping it alive.

GCC 9.1 released

GCC 9.1 is a major release containing substantial new functionality not available in GCC 9.x or previous GCC releases. In this release C++17 support is no longer marked experimental. The C++ front-end implements the full C++17 language (already previous GCC major version implemented that) and the C++ standard library support is almost complete. The C++ front-end and library also have numerous further C++2a draft features. GCC has a new front-end for the D language. GCC 9.1 has newly partial OpenMP 5.0 support and almost complete OpenACC 2.5 support.

Game Boy CPU manual

This document was designed to help you programming the Game Boy Classic, Game Boy Pocket, Super Game Boy and Game Boy Color (basics – you will need additionaldocuments for GBC specific programming). It was ment to be a complete handbook to start right off coding forthe hardware. The documents consists of three major parts. The first is the ‘GBSpec.txt’ (also known as the Pan Document) by Pan of Anthrox, Marat Fayzullin, Pascal Felber, Paul Robson, Martin Korth, kOOPa. This will be found in paragraph 1. The second is a mixture of several documents from ‘Game Boy Assembly Language Primer (GALP) V1.0’ by GABY (GAmeBoY). It contains opcodes, time duration and the affected flags per ASM command and the. This can befound in paragraph 2. The third is a summary of specifications and commands for Nintendo Super Game Boy speciffic programming bykOOPa and Bowser. See paragraph 3. Some light reading to kick off the week.

LLVM 8.0 released

LLVM 8.0 has been released. This release contains the work on trunk up to Subversion revision r351319, plus work on the release branch. It’s the result of the LLVM community’s work over the past six months, including: speculative load hardening, concurrent compilation in the ORC JIT API, no longer experimental WebAssembly target, a Clang option to initialize automatic variables, improved pre-compiled header support in clang-cl, the /Zc:dllexportInlines- flag, RISC-V support in lld. And as usual, many bug fixes, optimization and diagnostics improvements, etc.

Swift 5 released

Swift 5 is a major milestone in the evolution of the language. Thanks to ABI stability, the Swift runtime is now included in current and future versions of Apple’s platform operating systems: macOS, iOS, tvOS and watchOS. Swift 5 also introduces new capabilities that are building blocks for future versions, including a reimplementation of String, enforcement of exclusive access to memory during runtime, new data types, and support for dynamically callable types. You can test the new features and changes in an Xcode playground.

Is computer code a foreign language?

Maryland’s legislature is considering a bill to allow computer coding courses to fulfill the foreign language graduation requirement for high school. A similar bill passed the Florida State Senate in 2017 (but was ultimately rejected by the full Legislature), and a federal version proposed by Senators Bill Cassidy, Republican of Louisiana, and Maria Cantwell, Democrat of Washington, is being considered in Congress. The animating idea behind these bills is that computer coding has become a valuable skill. This is certainly true. But the proposal that foreign language learning can be replaced by computer coding knowledge is misguided: It stems from a widely held but mistaken belief that science and technology education should take precedence over subjects like English, history and foreign languages. This is silly. Programming is certainly not a replacement for foreign language skills. That being said, it’s somewhat defensible considering this is an American story, and since they speak English as their first or second language anyway, they can get by in the world pretty well as it is.

Wine 4.0 released

This release represents a year of development effort and over 6,000 individual changes. It contains a large number of improvements that are listed in the release notes below. The main new features in Wine 4.0 are Vulkan support, Direct3D 12 support, game controllers support, and high-DPI support on Android.

The Virtual Apollo Guidance Computer

This repository is associated with the website of the Virtual AGC project, which provides a virtual machine which simulates the AGC, the DSKY, and some other portions of the guidance system. In other words, if the virtual machine—which we call yaAGC—is given the same software which was originally run by the real AGCs, and is fed the same input signals encountered by the real AGCs during Apollo missions, then it will respond in the same way as the real AGCs did. The Virtual AGC software is open source code so that it can be studied or modified. The repository contains the actual assembly-language source code for the AGC, for as many missions as we’ve been able to acquire, along with software for processing that AGC code. Principal tools are an assembler (to create executable code from the source code) and a CPU simulator (to run the executable code), as well as simulated peripherals (such as the DSKY). Similar source code and tools are provided for the very-different abort computer that resided in the Lunar Module. Finally, any supplemental software material we have been able to find or create for the Saturn rocket’s LVDC computer or for the Gemini on-board computer (OBC) are provided, though these materials are minimal at present. The Apollo moonlanding project is probably one of the greatest – if not the greatest – technological achievement of mankind. Making sure we have all the tools and code necessary to study the code used is a vital project.

Go 2, here we come!

A major difference between Go 1 and Go 2 is who is going to influence the design and how decisions are made. Go 1 was a small team effort with modest outside influence; Go 2 will be much more community-driven. After almost 10 years of exposure, we have learned a lot about the language and libraries that we didn't know in the beginning, and that was only possible through feedback from the Go community.

The Go team s revealing some things about the future of the programming language.

Fortran is still a thing

In 2017 NASA announced a code optimization competition only to cancel it shortly after. The rules were simple. There is a Navier-Stokes equations solver used to model aerodynamics, and basically, the one who makes it run the fastest on the Pleiades supercomputer wins the first prize.

There were a few caveats though. The applicant had to be a US citizen at least 18 years of age, and the code to optimize had to be in Fortran.