iiinova — where your digital self keeps evolving

Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 01/10/2026

The Discrete Fourier Transform actually extracts phase information as well as pitch information, which I was just tossing away since it's not needed for pitch detection. But if I *don't* toss it away, and I apply the correct phase offset for each frequency I […] [Original post on teh.entar.net]

A screenshot of Decker running some pitch detection software. This time, the resynthesised waveform looks a *lot* like the original... but going from quiet to loud where the original went loud to quiet. It's also quieter overall.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 01/10/2026

Then it occurred to me to wonder, now that I can take a sound and pull it apart into its component frequencies, what happens if I generate sounds for all the frequencies and add them back together? It turns out, it makes a waveform that does look at least a […] [Original post on teh.entar.net]

A screenshot of Decker, running some software to do pitch detection. At the top left, a list of sounds, with "Sosumi" selected. To the right of that, the waveform of the selected sound. Below that is a frequency spectrogram and a list of the detected frequencies; the loudest is 880 Hz. Below that is another waveform of all the detected frequencies added back together - it visually resembles the original in frequency and texture, but the envelope is very different.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 27/06/2026

I have reorganised my Decker font importing tool to be a bit more approachable - rather than starting with a list of obscure font formats, it starts with some links to collections of high-quality fonts, with instructions (and screenshots!) describing how to […] [Original post on teh.entar.net]

A screenshot of a Decker card titled "Damien Guard's ZX Origins collection". It has a lot of text and hand-drawn pixel-art screenshots describing how to navigate the site, download a font, and find the specific importable files within.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 18/05/2026

I have begun writing a Decker deck that can import fonts from Rob Hagemans' Hoard of Bitfonts. It's been kind of painful because Decker's scripting language is a bit awkward at text manipulation, and the YAFF file format is geared for human consumption rather […] [Original post on teh.entar.net]

A textual representation of a table with five columns: "encoding", "strike", "left-bearing", "right-bearing", "codepoints". The "strike" column contains periods and at-signs, the others contain numbers.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 11/03/2026

I know Apple pushed the original Macintosh as "easy to use" but specifically calling out the familiarity of the *keyboard connector* seems a bit much. (from BYTE Magazine, June 1984: archive.org/details/byte-magazine-1… )

A close-up of a diagram of the original 1984 Macintosh. A callout line connects a socket with the label "Keyboard connector — a telephone-type jack you already know how to use."

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 03/03/2026

In the late 1990s, Pangea Software was a leading developer of Mac-exclusive games. Apple commissioned them to write demonstration code for the first release of the Quickdraw 3D graphics API, and their subsequent games Nanosaur, Bugdom, and Cro-Mag Rally were […] [Original post on teh.entar.net]

A screenshot of the game Nanoraptor, showing a dinosaur wearing a jetpack and running around a chunky late-90s 3D environment.

A screenshot from the game Bugdom, showing a blue-green cartoonish bug (six arms, two legs with cute sneakers) wandering on sandy ground, with a forest of giant grass blades in the background.

A screenshot of the game Cro-Mag Rally, showing a cave-man in a racing car made from a log and primitive stone wheels.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 12/09/2025

I have also added support for laying out items above one another, so I can finally have a row of annunciators, the display, and then the keypad making a proper, working calculator layout with all the required bits. So now I can finally test out the skins and […] [Original post on teh.entar.net]

A screenshot of the Plus42 and Free42 calculator apps on top of a mossy, rocky background image. They are each using the System 6-themed skin I've been working on, showing that the skin supports the extra buttons present on Plus42.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 12/09/2025

More interestingly, I can now also draw annunciators - those little status icons at the top of the display that tell you things like "the calculator is busy calculating" or "angles are measured in radians". I had fun coming up with appropriately Macintoshy […] [Original post on teh.entar.net]

The right-hand end of a MacOS Platinum pop-up list widget, showing up-and-down pointing triangles.

A screenshot of the Chooser desk accessory from System 6. On the left are icons for the various printers supported as output devices, including the ImageWriter, a dot-matrix printer with tractor-feed paper emerging from the top, and a chunky paper-advance knob on the side.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 12/09/2025

My calculator construction kit (for designing skins for the Free42/Plus42 calculator app) has progressed to the point where it can construct an actual complete skin. First up, I can now describe how I want the display to be rendered. Free42 always renders a […] [Original post on teh.entar.net]

A screenshot of Decker. A table on the left has entries "small" (magnification factor 1x1), "medium" (factor 2x2), "default" (factor 2x3), and "large" (factor 3x3). "Medium" is currently selected.

On the right, under the heading "Display Size" we see the medium display is 266x36 pixels. Under the heading "Display Preview" we see the left-hand edge of a mock-up Free42 display; each source pixel is indeed rendered as 2x2 pixels.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 27/08/2025

Another change: just for the heck of it, I drew a title-screen graphic. I decided to call it the "calculator construction kit", partially just so I don't have to keep calling it "this thing I'm working on", but mostly as homage to the tool the Macintosh team […] [Original post on teh.entar.net]

A screenshot of Decker. Across the top of the card it says "Calculator Construction Kit" in a pixelly monospaced font.

At the left is a picture of a calculator, crudely drawn with Decker's line-drawing tool. The screen says "3.14" to make it clear it's a calculator and not a security keypad or something.

On the right are a set of buttons that link to the various cards in the deck: "Draw button shape", "Define available buttons", "Group buttons into grids", "Render a button grid".

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 27/08/2025

This is the bit I've actually been working towards. As I think I mentioned before, on the 42S some buttons have a shifted function with a shaded background. Those functions open a menu, rather than performing an action immediately (a bit like the "..." suffix […] [Original post on teh.entar.net]

A screenshot of Decker, showing a calculator keypad drawn in the style of Macintosh user interfaces from the 1980s. Each button has a label on it, describing the primary function, and another smaller label directly above it for the shifted function.

Some of the shifted function labels have a 50% grey region behind them.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 06/08/2025

Even less obvious than that, I changed the way the corners of the buttons are drawn. Although I originally copied them from a screenshot of System 6, I was recently playing with System 6 in an emulator, and noticed that the buttons looked a little bit different […] [Original post on teh.entar.net]

The System 6 "Save" dialog, with 18px buttons. The corners have a ~3px radius, looking a bit thick and angular.

The System 6 "Page Setup" dialog for ImageWriter printers. The buttons are 20px tall, so they have a ~4px corner radius. They're rounder than the 18px buttons, but have a somewhat awkward "pointy" bit in the middle.

A screenshot of Disc Copy 4.2 under System 6. It has 25px buttons, with ~5px corner radius.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 06/08/2025

A number of changes since the last post: - I added more room at the top of the grid, leaving room for annunciators and the display - we now draw the grid of "pressed" button images beside the unpressed ones, as Plus42 expects - Not shown here, but the "layout" […] [Original post on teh.entar.net]

Yet another screenshot of Decker showing an HP 42s style keypad, this time with some extra Export buttons at the bottom.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 21/07/2025

After a little confusion and a lot of yak shaving, I now think I've ironed out all the issues I had in text measurement and rendering. There's no invisible whitespace pushing things to the left, the "0.5px" rounding errors that come from centering text are no […] [Original post on teh.entar.net]

Yet another screenshot of Decker, showing an HP42s style calculator keypad drawn in the style of a 1980s black-and-white Macintosh UI. Some of the button labels are shifted over by a pixel, compared to the previous screenshot, making them very, very slightly more visually pleasing.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 16/07/2025

However, there's something that confuses me. The "Winners Don't Use Drugs" campaign, part of Reagan's War on Drugs, was introduced in 1989 by the American Amusement Machine Association, with the cooperation of the various arcade companies that were members of […] [Original post on teh.entar.net]

The official FBI seal, centred on a navy blue background, with yellow text below saying "Winners Don't Use Drugs".

Except the first "U" has been left out of "Bureau". There's no gap, no sign of editing or Photoshop; somebody was creating the official artwork for the Seal, typo'd the name, and the result got past every single reviewer and QA person until it wound up burned into a ROM.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 04/07/2025

I spent some time messing around with Snow, a new low-level emulator for classic 68k Macintoshes. It doesn't support hard-drive images from Basilisk II (the most widely-used 68k Macintosh emulator), so I had to make a fresh, blank hard-drive image, grab some […] [Original post on teh.entar.net]

A black-and-white screenshot of System Software 7.5 being installed on an emulated Macintosh SE FDHD. We're up to disk 2 of... many, so clearly the floppy disk images are working.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 21/06/2025

I have now finished Taiyaki Fabulous Museum of Fish, and even after finishing the game and the post-game content and the post-post-game content it *still* found a way to surprise and delight me.

A screenshot of the final screen of the game, a pixel-art character afloat in a starry night sky. At the bottom of the screen, a text-box says "Your completion rate: 208%"

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 19/06/2025

Tonight I finally got around to investigating the button-spacing issue. Turns out that in #Decker a font has a "space" value that controls how many pixels are left between each character. If you ask Decker to measure the dimensions of the string "zzz", you'll […] [Original post on teh.entar.net]

A screenshot of a Decker deck, showing a scientific calculator keypad rendered to look like a classic 1984 Macintosh user interface. The labels are centred on the buttons, but not quite - some of them are a little to the left, making it a bit uncomfortable.

A screenshot of a Decker deck, showing a scientific calculator keypad rendered to look like a classic 1984 Macintosh user interface. This time, most of the labels are perfectly centred on the buttons, making it a little more pleasant.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 18/06/2025

OK, let's type it in, and see what it does... You know what, I don't need to type it in, I think I can guess.

A scanned-in printout of a a BASIC program. It contains only print statements, which contain a crude ASCII-art depiction of a conical flask.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 02/06/2025

From the Olean Herald, New York, on the 13th of September, 1884 (page 7, column 4), presumably quoted from a newspaper called the London Graphic.

Bill Stickers Frightened
[London Graphic]
A countryman named William Stickers, flying to London to escape from rural justice, was appalled at reading on a wall: "Bill Stickers Beware!" He went a little further, but reading again, "Bill Stickers will be punished with the utmost rigor of the law," gave himself up for lost and surrendered.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 20/05/2025

I finally wrote the code that combines the "button definitions" and "button grids" and "button shape" data to draw the actual Plus42 keys graphic. My first attempt is not pictured; some of the table rows that put a button in a grid used a numeric button ID […] [Original post on teh.entar.net]

A screenshot of Decker, with a list on the left ("p42keys" is highlighted) and on the right, a canvas displaying an approximation of the Plus42 default keypad layout, although it's currently a bit wonky.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 01/05/2025

You might also notice a "Back" button below the grid item list. Although Decker has a "Card" menu that lets you flip between cards manually, and even a "Card List" dialog that gives you a list of cards with thumbnails, it seemed more in the spirit of Decker and […] [Original post on teh.entar.net]

A screenshot of a Decker deck. The current card has three buttons: "Draw button shape", "Define available buttons", and "Group buttons into grids".

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 01/05/2025

You might wonder what that big 5 by 4 "button" is at the bottom right of the grid. The HP 42s uses slightly larger buttons for the numeric keys than for all the other function buttons, and so they live on a slightly different grid. Plus42's default layout […] [Original post on teh.entar.net]

A screenshot of the Plus42 calculator app, pretending to be an HP 42s style calculator with more rows of buttons. The numeric keypad portion of the interface uses wider buttons than all the rest, so they don't really align neatly, and there's a gap between the right-edge of the left-most column of buttons, and the left-edge of the right-most numeric buttons.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 01/05/2025

Another step on the journey: I now have a table that defines the size and position of each button in a grid, so I can lay out the buttons as necessary. As a visualisation, I also made a canvas that draws each button in its relative size and shape, and highlights the currently-selected button.

A screenshot of a Decker deck. On the left is a grid with a list of buttons, including their x and y coordinates, and their width and height. On the right is a 6 by 9 grid of boxes representing the buttons, one box is filled in.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 22/04/2025

Here's a view of my "Chicago Math" font which adds the mathematical symbols I need. In particular, I'm proud of the script "x", script "y", and script "e" glyphs replacing "{", "}" and "~". It wasn't easy to make a thing that looked like a classic mathematical […] [Original post on teh.entar.net]

A screenshot of Decker's font-editing deck, showing a variant of the classic Macintosh "Chicago" font, with various ASCII punctuation symbols replaced with mathematical ones.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 22/04/2025

I've made a table with all the button IDs that Plus42 supports, the label of each button, the shifted label, and whether the shifted function is a submenu. Unfortunately, Decker's default character set does not include all the symbols that appear on Plus42's […] [Original post on teh.entar.net]

A screenshot of a Decker card. On the left is a big table with columns "id", "label", "shifted", and "ismenu". The highlighted row has label "1/{" and shifted label "}'". On the right is a legend describing what mathematical symbol is represented by each punctuation mark, including "Script x: {" "Script y: }", and "Superscript x: '". In the bottom right is a Test area, depicting a button labeled "1/x", with shifted label "y to the power of x".

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 19/04/2025

Another day's work, and now I have a function that renders a custom button. Now there's four button templates at the top-left, for every combination of "normal vs. pressed" and "the shifted function executes a command vs. the shifted function opens a submenu" […] [Original post on teh.entar.net]

Another screenshot of the Decker app, struggling to fit all the required widgets into the available space.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 15/04/2025

Here's how far I got after a few hours' messing about. Although Decker has a "canvas" widget, it's really for code to draw on, rather than the user. However, the user is allowed to draw directly on the background of each card, so on the left I have little boxes […] [Original post on teh.entar.net]

A screenshot of Decker displaying a card. On the left are some button-shaped squares, on the right are a bunch of fields describing the size and position of the rectangles, and formatting details (font, text colour) of the resulting button. At the bottom-right is a rendered image of the button, with the text "Hello".

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 31/03/2025

Free42, the Free Software re-implementation of the classic HP 42s RPN calculator, supports using custom skins, a bit like WinAmp skins but more complex - instead of just a bunch of bitmaps, you get to define the size and location of each button and graphical […] [Original post on teh.entar.net]

A screenshot of a web-browser. On the left-hand side of the page, a textarea contains long lists of coordinates, one corresponding to "Key 8" is highlighted. On the right hand side, a photo-realistic image of a calculator resembling the HP 42s, along with a "pressed" version of all the calculator keys. Highlights on the image cover the pressed and unpressed images of the RCL key, and below the image, a caption says "Key: 8 name: RCL".

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 05/02/2025

`variable.bdf` is a pretty standard, unobjectionable sans-serif user-interface font that doesn't really stand out in any way. In a directory full of graphic weirdness like pictures of the Enterprise and Cyrillic fonts scanned from paper, that simplicity makes […] [Original post on teh.entar.net]

Crisp, clean letter forms, even spacing, it's lovely.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 05/02/2025

`lat-s30.bdf` is another one from the Lisp Machine. It's a reasonably standard thin, monospaced typeface, except that A, E, I, and U (but not O) have macrons permanently above them; C, G, S, and Z permanently have carons; and K, L, N, and R permanently have […] [Original post on teh.entar.net]

A standard-looking monospaced typeface, except that many alphabetic characters have unnecessary accents.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 05/02/2025

`dancer.bdf` has crisp, clean monospaced numbers and letters, but also a bunch of lines and shaded boxes. Perhaps these were used for choreography notation? Who knows what those MIT folk got up to in the 1980s.

A font with numbers and letters, but also squares with a blob on one side, outlined squares, shaded squares, and various horizontal and vertical lines.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 05/02/2025

`crturz.bdf` has the internal name "cartoon". I have no idea what it's supposed to represent, but those diagonal patterns suggest that whatever tool converted it to BDF got the stride length wrong.

A font with one character repeated twice, which is a noisy mess resembling an analogue television with the horizontal sync messed up.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 05/02/2025

`apl-s25.bdf` contains APL symbols, which is handy if you're into that. A comment says 'the Lisp Machine name for this font was "s25apl.ast"'.

A nice italic, serif typeface with a bunch of weird symbols used for programming in APL.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 18/01/2025

Are you nostalgic for using a CRT terminal in the 90s? Or maybe curious about what things looked like before high-DPI displays and true-colour graphics? I've extracted the fonts from the firmware of the DEC VT320, a CRT terminal first produced in 1987, and […] [Original post on teh.entar.net]

A screenshot of the app "Cool Retro Term" trying to simulate the text rendering of a VT320 with an amber screen. The text is a warm, rich orange; the background is dark with some ambient glare, and curves away towards the corners of the screen.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 16/01/2025

If we take the left-most column of pixels and stick it on the right, we get a much cleaner pattern - all the pixel blocks are 2×2, and although some of the gaps are still 3×2, at least they're evenly distributed. Since the glyph is 9px wide, it's not really […] [Original post on teh.entar.net]

White ones and zeros in a checker-board pattern on a 9×12 grid, on a blue background in a terminal.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 16/01/2025

Here's another example. This is the 132-column glyph for "U+2592 MEDIUM SHADE", all on its own. It looks like a glitchy, uneven mess - some blocks are 2×2 pixels, some are 1×2, some of the spaces between blocks are 2×2, some are 3×2.

Wouldn't you know it, even more white-on-blue terminal text.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 16/01/2025

But I don't think it's actually that simple. Here's another character, this time it's "U+25A1 WHITE SQUARE". The wide version is a nice neat normal 9×12 pixel rectangle with a 1px outline, while the narrow version has a 1px outline top and bottom, a 2px […] [Original post on teh.entar.net]

Another screenshot of white text on a blue terminal background.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 16/01/2025

Here's the raw data for another character, which Unicode poetically names "U+251C BOX DRAWINGS LIGHT VERTICAL AND RIGHT". Again, you can see a wide version on the left and a narrow version on the right, with the "=" markers above the wide version and the "-" […] [Original post on teh.entar.net]

Another screenshot of white text on a blue background in a terminal.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 16/01/2025

However, within each table of glyphs, the 80-column and 132-column glyphs are stored next to each other. I mean, *right* next to each other. In the "symbol" table, each scanline is stored as three bytes, where the most significant 15 bits are for the 80-column […] [Original post on teh.entar.net]

A screenshot of blue-on-white text in a terminal.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 16/01/2025

Except, it's not *quite* perfect. Look at those box-drawing characters... what's with those extra stray pixels? And why do those rectangle characters near the end have one side open?

A close up of the box-drawing characters at the end of the font. Stray pixels are visible at the left of characters that connect to the right side of the box.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 16/01/2025

I've also extracted the glyphs for the 132-column mode, and they're looking pretty good too.

A screenshot of the ftview program showing another font with all the same glyphs, but horizontally condensed.

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Screwtapello @screwtapello.teh.entar.net.ap.brid.gy · 16/01/2025

To help out @vga256 I'm writing a program to extract the font from the DEC VT320 firmware. It's going pretty well, I've got all the glyphs for the 80-column mode, and I figured out how to correct for the VT320's extremely non-square pixels, so it looks quite readable.

A screenshot of the ftview tool displaying all the glyphs in the 80-column font in the DEC VT320 firmware - all the ASCII characters, a bunch of accented characters, and some box-drawing characters.

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