Well, V7 UNIX is rather arbitrary as a reference point for comparison. There was what we now call as V1 UNIX, which would be circa 1971/72, so that's certainly 50+ years old. Compared to what's shown in the article, some of the data structure fields and constants would be different and/or missing in the still earlier versions. DIRSIZ would be 8, for example.
The fancy names and the layering makes it a little tricky to understand. The core of the imaging model is called Quartz. It provides support for rendering 2D shapes and text. Its graphics rendering functionality is exported through the Quartz 2D API, which is implemented in Core Graphics. Quartz is also used for window management: the Quartz Compositor, a lightweight window server, is implemented partly in the WindowServer application and partly in the Core Graphics framework. Quartz 2D uses PDF as the native format for its drawing model. In other words, it stores rendered content internally as PDF, which facilitates features such as automagic PDF screenshots, export/import of PDF data natively, and rasterizing PDF data. Quartz 2D also does device-independent and resolution-independent rendering of bitmap images, vector graphics, and anti-aliased text. NEXTSTEP's window server was based on Display PostScript, so was Sun's NeWS (~1986).
NeWS wasn't based on DPS. It's a full display server based on the PostScript Red Book with some extensions (canvases, lightweight processes and sync primitives, events, classes, garbage collection). This allows to write applications in this extended PostScript or in other programming languages, using a preprocessor, such as cps for C or lps for Scheme-48 and Allegro LISP, that generates PS snippets that get sent to the server.
As part of a project code-named "Jaguar", Apple did consider using a Motorola 88K variant as their future RISC-based hardware, but it was short-lived and they moved on to the POWER Architecture. In 1991, Apple, IBM, and Motorola formed the "AIM" alliance with the goal of creating a Common Hardware Reference Platform (CHRP). This led to the PowerPC architecture, which included most of the POWER instructions along with some additions and deletions.
No, not quite. The macOS/iOS kernel is extremely Frankenstein-y (not meant in a derogatory way), with the majority of codebase being extremely Apple-specific, and bits and pieces originally taken from Mach and BSD. In particular, there is no microkernel, and there never was. Mach itself was never used as a true microkernel in a commercial setting, with the first such implementation--Mach 3--showing significant real-life performance problems. As such, there is no "BSD on top of a Mach microkernel". It is and has always been a fully monolithic kernel with some subsystems originally derived from Mach (Open Group's Mk 7.3), some from BSD (FreeBSD 5), and the rest developed in-house over the years. Even the layerings aren't always clean, with "on top of" often morphing into "alongside" or "intertwined with".
What is interesting about Mach to me. Is that now 40 years later it's returning too it's roots of hosting multiple OS's on a single hardware architecture. Apple being able to design to M series chips to match Mach's paper over Mach's deficiencies and leverage it's strength I find very exciting.
Originally it was meant to be the foundation computing layer for a campus full of devices.
At the time of this writing (mid 2021), US tax breakdown for the highest income bracket in California is as follows.
# Federal
* Long Term Capital Gains Tax = 20%
* Short Term Capital Gains Tax = 37%
* Earned Income / Ordinary Income Tax = 37%
* Net Investment Income Tax = 3.8%
* Medicare Payroll Tax (W-2 Wages) = 1.45%
* Additional Medicare Tax (W-2 Wages) = 0.9%
# State (California has the highest rate)
* CA State Income Tax = 12.3%
* CA Mental Health Tax = 1%
In summary, if you make "a lot" of money in California, you'd be paying combined Federal/State taxes of at least 37.1% and as much as ~55%, depending on the type of income. Deductions and credits mostly phase out at said income levels. In particular, Trump's doing away with the State and Local Tax (SALT) deduction meant that now you also pay both Federal and State taxes on the same income as if the other tax (Federal or State) did not exist.
You left out FICA, but it's also worth noting that the W-2 taxes have a maximum for the year, so the income bracket of 37% does not overlap with W-2 taxes.
Sure, but that's why you'll see that my summary totals aren't just a summation of all the enumerated percentages. The point is to illustrate what the total tax range is at the highest income levels.
