I got a reasonably priced copy of the book "Z-80 and 8080 Assembly Language Programming" by Kathe Spracklen, 1979. It provides a clear and concise reference and comparison of the Z80 and Intel 8080 instruction sets.

I posted some notes on why I like the book:


DALL·E, what part of "The Moon seen from the window of a spacecraft in lunar orbit" don't you understand?

This is pretty cool: the Serial USB Terminal Android app on chromeOS on my ASUS Chromebox 3. The terminal is running a CP/M 3.0 session on a Z80-MBC2 Z80 homebrew computer connected to the Chromebox via serial USB.

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I got my hands on these gems, books 1 and 2 of "8080-8085 Software Design" by Larsen and Titus, 1981.

Focus on iterative design, countless examples clearly and fully explained in detail, coverage of programming all sorts of peripherals and devices, extensive discussion of data structures and algorithms. The only downside is a weird Assembly notation.

I'm playing with UCSD p-System, one of the operating systems that come with the Z80-MBC2 Z80 homebrew computer. Here's a demo program that plots a sine wave.

The menu system is easy, but I'm not sure I understand how to go back one level. Pressing Q works most of the times but not all. I tried ESC, Backspace and a few more keystrokes without success.

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The so called productivity app launched rolled out to my ASUS Chromebox, here's what it looks like on the desktop.

I'm okay with it. But I wish it had buttons for the most recently used apps, like the old launcher.

An interesting item I saw on display at the American Space Museum in Titusville, FL, is this WWII era slide rule with the label "SUN - HEMMI MADE IN OCCUPIED JAPAN".

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Rummaging through GitHub I discovered an inconspicuous repo that's actually a gem. z80-tools is a Z80 development environment with an editor, assembler, debugger, terminal emulator, and other tools.

The screenshot shows z80-tools running under Crostini Linux on my Chromebox.


It looks like I caught on camera the early construction work at the site of Starship's service tower inside launch complex 39A, at Kennedy Space Center. This is a crop of a photo I took on April 21, 2022 at the Crew-4 "wave across the ditch" event I mentioned here, where you can see the full frame:


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I still have a copy of the book "Project Oberon: The Design of an Operating System and Compiler" by Niklaus Wirth and Jürg Gutknecht, published in 1992.

I was fascinated by the coherent operating system, development tools, and GUI stack, the elegance of Wirth's design, and graphics workstations.

An example of what it's like to use Google products outside of the US is the main screen of the Screenshot app, a new chromeOS screen recording app.

On my Chromebox set to Italian, the new screencast button "Nuovo screencast" is grayed out as audio transcription, the key feature available only in English, is not localized. Many such AI-based products or features never make it oustide of the US, or work only in part.


These Space Shuttle launch control center consoles, used at Kennedy Space Center in the 1980s or 1990s, had a mix of digital computers and analog controls such as switches, buttons, dials, and indicator lights.

I took these photos at the American Space Museum in Titusville, FL.

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My night view from Kennedy Space Center's Banana Creek viewing site half an hour before the Crew-4 launch.

At the horizon, the lit area at left is the 39A pad with the Falcon 9 rocket. The iconic VAB is at right. The bleachers are mostly empty because many crew guests had left over the previous days, as their travel arrangements didn't accommodate the multiple launch delays.

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chromeOS 103.0.5060.64 landed on my Chromebox.

Now clicking the Crostini Terminal icon brings up a dialog instead of the Linux container shell as before. There are options for starting and managing Linux containers, creating SSH connections, and accessing the terminal and the developer settings.

Mars Rover Photos is a good Android app for viewing images from the surface of Mars, as it combines the feeds of the images taken by NASA's current and past rovers and landers.

But it presents a confusing ordering of the images and isn't being updated with the latest ones. Also, the developer still hasn't released the paid, ad-free version of the app he told me about over a year ago.

Here's the app on my Pixel 4 XL.


This is pretty much the best lunar detail I can catch with my Pixel 4 XL at 2X optical zoom. I shot the photo in RAW on 25 Mar 2021 at 17:12 UTC, then processed the DNG file with Photopea to adjust the levels, crop, and rotate.

In a few months I'll hopefully get a Pixel 7 Pro. I look forward to shooting the Moon with its camera at the maximum optical zoom level.

Playing with the Z80-MBC2 is a fun retrocomputing project. So here are the obligatory vintage cool-retro-term screenshots of this Z80 homebrew computer running CP/M 3.0 and a couple of games.

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In this Minicom terminal emulation session, an Intel 8080 Assembly hello world demo runs under CP/M on a Z80 homebrew computer.

Nothing fancy, but for me it's an incredible personal achievement. I assembled the demo's 8080 source with an assembler I wrote myself. I posted a bit more about the project here:


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The American Space Museum in Titusville, FL, is among the few such venues where you're encouraged to touch stuff. And there's a lot to touch in this roomful of early Atlas rocket launch control center consoles.

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It works!

I made chromeOS detect the Z80-MBC2 Z80 computer connected via USB by... re-plugging the board. In the screenshot, see the Z80-MBC2 booting up CP/M 3.0 in a Minicom session under Crostini Linux. More details here:


Time to play with this awesome little gadget. The "Z80 inside" logo alone is worth the product.

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