“Fully operational mini version of the IBM PS/2 Model 25 from 1987, recreated using a Raspberry Pi 4B as the computer.
The original has an all-in-one design, which mimicked the popular original Macintosh. There are several variants, but the one our family owned was an Intel 8086 8MHz CPU, 12” MCGA display, 720KB 3.5” disk drive, and 512KB RAM. I no longer own this, but after seeing this project of a mini Commodore 64 monitor, it seemed possible that the PS/2 25 could be likewise crafted.
This version is built around a 10.4” 1024x768 LCD Panel, the Raspberry Pi, and a 10A power supply. It also features mounting for a power-switch that is very similar to the original, working LED power and disk activity lights, a spring loaded eject button (otherwise non operational), audio amplifier with control knob and speaker mounting, and mounting for a switching headphone jack. See all the parts listed below.
Here is the printables page with all the STL for the pieces.
There are more than a few pieces to fit together. Many of them don’t require much (or any) printing support. All the components are mounted using threaded inserts and bolts, but the case itself is mostly attached using super glue. The pieces have small lips and groves at their adjoining edges to help guide a good fit. Clamps are highly recommended for securing them together tightly. Included are STEP files for the display bezel and the electronics mounting board. It should be possible to modify the bezel to accommodate a similarly sized display panel, and another single board computer could be fit.
The printing was all done on an Ender 3. A few of the pieces (the case bottom and rear panel) take up most of the bed - mine required some fine tuning to get good first layers.
Supplies
3D Files: STL on printables
3D Printer Filament
This used all PLA2/plus. If finishing with paint, any neutral color will be fine. Here are some that are pretty close to the desired colors:
- Inland PLA Plus - Bone White
- FilaCube PLA2 - Greyish Brown
- SUNLU Neatly Wound PLA Filament - Black
Electronics and Hardware
- ItemSource 10.4 inch 1024x768 Brightness 500nits IPS LCD Screen
- Ask seller for 50cm keyboard cable, the standard 30cm won’t quite reach the rear panel_
_- Raspberry Pi 4b
- …and storage card
- Micro HDMI to HDMI
- Switch Power Rocker DPST 10A 125V
- the red looks very similar to switch on original IBM PS/2_
- 5.5mm DC Pigtail
- used to power the monitor at 12v
- USB C Type-C Male Plug Cable
- used to power the Raspberry Pi at 5v
- 60mm Fan
_- 12V 10A 120W DC Switching Power supply
- Buck Converter DIY Power Supply Step-Down Module
- Power Cord Inlet Socket
- Power Cable - 14 AWG_
- Hook up wire
- Spade Terminals, Fork Terminals, Dupont Connectors
- Heat Shrink Tubing
- Micro SD to SD Card Extension Cable Adapter
- This product was meant to be used in the diskette slot as an SD card reader. They seem to work when testing outside the computer, but after assembly, there’s a variety of errors when reading a card through this device. Aluminum foil was tried to minimize EM noise, wrapping it around the cable, but with no luck. Three different devices with two different sizes of cables were tried. It’d be a great feature to have an external slot for the drive - if you have any suggestions, please leave a comment.
- 3MM LED - Two Green
- Two 150+ ohm Resistors for the LEDs
- Spring, 8mm diameter, 18 length
_- Speakers (2)
- 64.3mm diameter speaker mounts - Dayton Audio DMA58-4 2” Driver
- 73.5mm diameter speaker mounts - Dayton Audio PC68-4 2-½” Driver
- Stereo Audio Amplifier Icstation TPA3116D2 *
- Headphone Jack STEREO 3.5MM R/A (backup datasheet, if original gives 404)
- 3.5mm Headphone Pigtail
- Micro HDMI to HDMI
- Prototype circuit board
- JST-XHP Connectors
Threaded Inserts and Bolts
- Threaded Inserts - M2 x 6mm
- Bolts, Washers - M2
- Threaded Inserts - M3 x 6mm
- Bolts, Washers - M3
- M2 riser
Finishing Supplies
- Super Glue
- Glazing & Spot Putty
- Sand Paper - 100, 400, 1000
- Case Spray Paint “Heirloom”
- Bezel Spray Paint “London Grey”
- Electronic Board Paint “Onion Grey”
- Acrylic Paint for Details
- Spray Lacquer
Tools
- 3D Printer
- Clamps for gluing, a bunch of them in various sizes
- Precision screw drivers and Hex screw drivers
- Precision tweezers
- Wire Stripper
- Cable crimper
- Terminal Crimper
- Soldering iron and solder
- Soldering stand/clamp
- Heat gun”