With my recent retro mac classic inspired enclosure project for the Fruit Jam, I got the crazy idea to display my own images on the mac emulator. Sure, you can run MacPaint, but wouldn't it be cool to display custom graphics like the Fruit Jam logo? Well, it turns out there's a bit of a process to get images to display on System 7.5, specifically on 68K architecture (which is what the pico-mac emulator is based on).

Mini vMac Workflow

My first problem to solve was, how do I even get files onto my pico-mac image? Thankfully, there's documentation on setting up Mini vMac via their website. Walking through the various "recipes" tutorials, I spent time learning how to load various disk images onto the Mini vMac emulator. Once I got the initial baby steps, I was able to load the premade macImage.img from the pico-mac fruit jam learn guide. To import files from my modern iMac M1 to the Mini vMac emulator, drag-n-drop the importfl-1.2.2.dsk onto to the Mini vMac emulator and copy ImportFl app onto your hard drive. This allows you to drag and drop files from my iMac M1 to the System 7 emulator on Mini vMac. With that figured out, the next step was to find a classic mac os app that can display image files (pictures, not to be confused with disk images).

Image File Formats

JPEG, PNG and GIF images are the norm with modem day computers. But, in 1984, these image formats were not yet a thing. I thought, surely displaying a bitmap image on Mac OS System 7 shouldn't be too hard, right?

After searching google, easiest approach seemed to be: Use the Graphic Converter mac app to convert a JPEG into a MacPaint document. This however, didn't quite seem to work. When I import the converted macpaint image file into Mini vMac, it wouldn't open in MacPaint. Weird, Ok, lets try a native image file format. Again, that's not really a thing. Enter the world of the .PICT (QuickDraw picture).

PICTViewer

After trying out various apps, I stumbled upon the PICTViewer app that is apart of the Apple Color Disk software from the macintosh garden website. This disk image has a copy of PICTViewer that can run on the System 7, 68K architecture, and bonus, it has sample PICT images that actually can be opened and displayed. The app is found in the 32BQD Demos.img inside the demos folder.

Convert JPEG to PICT

Now that I have working image view app and some sample images that are confirmed working, I can move to converting modern JPEG images to the PICT file format. Unfortunately, the native the Preview app for macOS (and even Photoshop 2026) do not have an export option for PICT images. Oddly, these app CAN open PICT images. There are online image converters that offer PICT output but I settled on the GraphicConverter app for macOS. A free trail allows you to quickly convert any JPEG to PICT. Just be aware of image size and file size. These images should be with the 800 x 480 resolution I had set for my pico-mac build. So, once I had my own image converted to PICT. It's just a one step away from using the ImportFl app to get it onto the Mini vMac emulator right? Ugh, nope.

ResEdit to the Rescue 

For some strange reason, when I imported my PICT images, they would show up as a binary file. Even stranger, they would automatically open in the StuffIt Expander app (used for extracting .sit archives). Opening them directly from the PICTViewer app was a no go, as they just were not recognized. If only there was a way to directly change the file format. ResEdit does exactly just that. Downloaded from the macintosh garden website ResEdit 2.1.3 allows manipulation of file types. Just open the broken PICT file, and change the type from BINA to PICT and creator from SITx to MDTS, save and close. This essentially applies the correct file type to the pict images. Once closed, bingo, the pict files show the correct file icon and open automatically in the PICTViewer app.  

And finally, I was able to display the Adafruit logo on pico-mac emulator, running System 7, 68K architecture. From what I understand, the PICTViewer app does the image decoding automatically. I was able to grab the sample "Pyramid" PICT from the demo disk image using the ExportFl app and actually display it on my modern iMac M1. To my surprise, it's actually a colored RGB image. It even opened in the native Preview.app (after applying the .pict file extension). So i'm guessing the PICTViewer app does the dithering for converting RGB into grayscale black and white images.

AfterDark Slide Show

So what's next? Naturally, I converted a few PICT images, organized them in a pictures folder and now displaying as a screen savor using the Slide Show screen savor that's apart of the After Dark screen savor collection. This provides a nice black background and centers the PICT images nicely. There's option to set a custom display time so they can be shown for a desired amount of time before it advanced to the next image. So there you have it, that's how I was able to display modern day images on pico-mac System 7.