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Build Instructions for the X3L Computer Case

This document describes how to assemble a X3L case for the Omega Home Computer.

Bill of Materials (BoM)

Acrylic parts

Computer case (4mm thickness)

The X3L Computer case for the Omega Home Computer is made up of seven panels:

  • Rear panel (where all the rear connectors are placed)
    • Dimensions: 360.00mm x 60.60mm x 4mm
  • Left panel (where the floppy disk drive front is located)
    • Dimensions: 303.95mm x 60.60mm
  • Right panel (where the audio/video knobs are attached)
    • Dimensions: 303.95mm x 60.60mm
  • Front panel (where the joystick ports are secured)
    • Dimensions: 360.00mm x 28.96mm
  • Bottom panel (where the motherboard sits)
    • Dimensions: 360.00mm x 312.00mm
  • Top panel (where the top slot is located)
    • Dimensions: 360.00mm x 165.76mm
  • Keyboard panel (where the keyboard is attached)
    • Dimensions: 360.00mm x 148.92mm

Laser cutting

The Omega Computer X3L case CAD design requires a 4mm thick acrylic sheet and has 20 layers that must be processed in this order:

Layer Name Color Operation Required Comment Processing Order
engraving-raster blue engrave recommended Rasterized fonts 1
engraving-raster-msxlogo blue engrave recommended MSX logo 2
engraving-vector cyan engrave recommended Vectorized fonts 3
case-top-keyb-int-1 red cut mandatory internal cuts for spacers 4
case-top-keyb-int-2 red cut mandatory external cuts for spacers 5
case-top-keyb-int-3 red cut mandatory internal cuts for keyboard plate 6
*-int (7 layers) red cut mandatory internal cuts 7
*-ext (7 layers) green cut mandatory external cuts 8

Tools

I used the following tools to build the Omega computer case:

  • torx screwdriver (8x60)
  • philips screwdriver
  • wire stripper & cutter (Stanley FatMax)
  • soldering station (Yihua 908D)
  • hot air gun
  • JST1.25 crimping tool (IWS-2820M)
  • XH2.54 crimping tool (SN-01BM)
  • Dupont crimping tool (SN-28B)
  • Ferrule crimping tool (HSC8 6-4)
  • portable drilling machine with countersink 20.5mm drill bit for acrylic

Mechanical parts

item count style material color length (mm) link
12mm mini push button switch, momentary, 2 pin 1 momentary metal red 12 aliexpress
18AWG silicone wire black 1 flexible silicone,copper black 300 aliexpress
18AWG silicone wire red 2 flexible silicone,copper red 300 aliexpress
20AWG silicone wire black 1 flexible silicone,copper black 100 aliexpress
20AWG silicone wire red 1 flexible silicone,copper red 100 aliexpress
22AWG silicone wire black 3 flexible silicone,copper black 400 aliexpress
22AWG silicone wire blue 3 flexible silicone,copper blue 400 aliexpress
22AWG silicone wire red 3 flexible silicone,copper red 400 aliexpress
22AWG silicone wire yellow 1 flexible silicone,copper yellow 400 aliexpress
24AWG silicone black wire 1 flexible silicone,copper black 180 aliexpress
24AWG silicone blue wire 1 flexible silicone,copper blue 350 aliexpress
24AWG silicone green wire 1 flexible silicone,copper green 250 aliexpress
24AWG silicone red wire 1 flexible silicone,copper red 180 aliexpress
24AWG silicone white wire 1 flexible silicone,copper white 600 aliexpress
26AWG silicone wire black 1 flexible silicone,copper black 400 aliexpress
26AWG silicone wire red 1 flexible silicone,copper red 450 aliexpress
28AWG silicone wire black 1 flexible silicone,copper black 250 aliexpress
28AWG silicone wire black 1 flexible silicone,copper black 120 aliexpress
28AWG silicone wire red 1 flexible silicone,copper red 370 aliexpress
28cm Male jack cable adapter plug 5.5 * 2.1mm 18 AWG 1 cable plastic,copper red,black 280 aliexpress
4 Ohm 3W mini speakers 2 mini plastic black 20 aliexpress
4-pin floppy power cable 30cm 1 4-pin plastic,copper red,black,yellow 300 aliexpress
5.5mm x 2.1mm DC power jack socket female panel mount barrel connector 11mm 1 5.5x2.1 metal metal 16 aliexpress
Blu Tack reusable adhesive putty 1 adhesive putty blue 0 aliexpress
Dupont female pin 6 female copper metal 12 aliexpress
Dupont female sleeve 2-pin 3 sleeve plastic black 14 aliexpress
E0508 bootlace ferrules 0.5mm2 white 3 bootlace plastic,copper white 14 aliexpress
Heat shrink tube black 1 tube plastic black 80 aliexpress
Heat shrink tube blue 1 tube plastic blue 20 aliexpress
Heat shrink tube green 1 tube plastic blue 20 aliexpress
Heat shrink tube red 1 tube plastic red 70 aliexpress
JST 1.25 Male 2-pin plug with wire 15cm 28awg 2 male,cable plastic,copper red,black 150 aliexpress
JST1.25 2-pin male plug 2 male plastic white 0 aliexpress
JST1.25 male pins 4 male copper metal 0 aliexpress
KF2510 8-pin female connector 1 8p,female plastic white 0 aliexpress
KF2510 female pins 8 female copper metal 0 aliexpress
M3 4-40 UNC 5/16 inch ~8mm 8 pan head, philips stainless steel metal 7.9 aliexpress
M3 4mm spacers 11 round nylon white 4 aliexpress
M3 countersunk washer 34 countersunk aluminium light blue 2 aliexpress
M3 female-female post 10mm 6 round aluminium light blue 10 aliexpress
M3 female-female post 16mm 2 hex nylon black 16 aliexpress
M3 female-female post 22mm 1 hex nylon black 22 aliexpress
M3 female-female post 25mm 4 round aluminium light blue 25 aliexpress
M3 female-female post 45mm 5 round aluminium light blue 45 aliexpress
M3 female-female post 50mm 3 round aluminium light blue 50 aliexpress
M3 female-female post 6mm 5 hex nylon black 6 aliexpress
M3 male-female post 20mm+6mm 1 hex nylon black 20 aliexpress
M3 screw 14mm countersunk 4 countersunk, torx stainless steel metal 14 aliexpress
M3 screw 16mm countersunk 11 countersunk, torx stainless steel metal 16 aliexpress
M3 screw 8mm countersunk 19 countersunk, torx stainless steel metal 8 aliexpress
M3 screw 8mm flat 6 flat, torx stainless steel metal 8 aliexpress
M3 silicone washers 4 round silicone white 2 aliexpress
Machined metal aluminium potentiometer volume knob 20x15mm 1 round aluminium light blue 20 aliexpress
Mini PAM8403 DC 5V power audio amplifier board 1 pcb n/a green 29.5 aliexpress
Miniature toggle switch red MTS-102 on-on SPST 3-pin 1 mini metal red 0 aliexpress
Rocker switch KCD1-101 ON-OFF 3-pin SPDT 1 3-pin SPDT plastic black 23.2 aliexpress
XH2.54 2-pin female straight connector 2 female-straight plastic white 0 aliexpress
XH2.54 2-pin male right angle connector 1 right-angle plastic white 0 aliexpress
XH2.54 3-pin female straight connector 1 female-straight plastic white 0 aliexpress
XH2.54 3-pin male right angle connector 1 right-angle plastic white 0 aliexpress
XH2.54 4-pin female straight connector 1 female-straight plastic white 0 aliexpress
XH2.54 4-pin male right angle connector 1 right-angle plastic white 0 aliexpress
XH2.54 female pins 11 female copper metal 0 aliexpress
XT30 female connector 1 female plastic yellow 20.2 aliexpress
XT30 male connector 1 male plastic yellow 20.2 aliexpress

Step by step instructions

Keyboard

  1. Prepare to attach the keyboard board to the keyboard panel using six posts/spacers

The six posts sit on the keyboard board top side and are fastened via screws on the bottom side. The keyboard panel then sits on top of the posts.

Place the keyboard board upside down and prepare the following parts:

  • 6x M3 8mm flat torx screws
  • 6x M3 10mm female-female posts

Keyboard: Prepare spacers

  1. Fasten the six screws on the keyboard board bottom side to the six posts/spacers on the keyboard board top side

Keyboard: Attach spacers

  1. Turn the keyboard and check that the posts/spacers are correctly fastened

Keyboard: Verify spacers

  1. Place the keyboard panel on top of the keyboard board and prepare to secure it with six screws in the previously installed spacers

Prepare the following parts:

  • 6x M3 8mm countersunk torx screws
  • 6x M3 countersunk washers

Keyboard: Add panel and prepare screws

  1. Fasten the six screws to attach the keyboard panel to the keyboard board posts/spacers and prepare to install the vertical posts that will secure the keyboard panel to the computer case

Prepare the following parts:

  • 4x M3 8mm countersunk torx screws
  • 4x M3 countersunk washers
  • 2x M3 25mm female-female posts (low half pair, on holes 2 and 3)
  • 2x M3 45mm female-female posts (high half pair, on holes 1 and 4)

Keyboard: Attach panel and prepare posts

  1. Fasten the four screws on the keyboard panel top side to the spacers/posts on the keyboard panel bottom side

The 45mm posts on the high half and the 25mm posts on the bottom half provide a comfortable/ergonomic angled position for the keyboard.

Keyboard: Attach posts

  1. Turn the keyboard panel upside down and check that the spacers/posts are correctly fastened

Keyboard: Bottom view

  1. Turn the keyboard again and prepare to attach the reset switch to the keyboard panel

The reset switch is a panel mount momentary push switch that attaches via a Dupont two pin female connector to the RST header on the Omega computer motherboard.
The cable length for the reset switch should be long enough (about 35cm) to allow the keyboard panel to be placed aside the computer without having to disconnect it.

Prepare the following parts:

  • 1x panel mount reset switch
  • about 35 cm of 24 AWG silicone blue wire
  • about 35 cm of 24 AWG silicone white wire
  • 2x Dupont female pin
  • 1x Dupont female sleeve 2p
  • heat shrink tube blue
  • heat shrink tube black

Keyboard: Prepare reset switch

  1. Attach the reset switch to the keyboard panel reset switch hole

Keyboard: Attach reset switch

Rest of Computer

  1. Place the bottom panel on a work surface and locate the eleven holes needed to secure the motherboard

  1. Prepare the spacers, washers and screws needed to secure the motherboard to the bottom panel

Prepare the following parts:

  • 11x M3 16mm countersunk torx screws
  • 11x M3 countersunk washers
  • 11x M3 4mm spacers

After laser cutting the keyboard panel you will get 12x 4mm spacers that can be used here, or alternatively you can use 12x 4mm nylon spacers.

  1. Turn the bottom panel and insert (from the bottom side) the screws that will secure the motherboard to the bottom panel

  1. Temporarily add Blu-tack on top of the screws to prevent them from falling down when turning again the bottom panel

  1. Turn now the bottom panel in preparation for inserting the spacers between the panel and motherboard

  1. Insert the spacers between the bottom panel and motherboard

  1. Carefully align the motherboard and slide it down so that it sits on top of the spacers

  1. Add small female-female posts to secure the slot screws and the screw to the right of the motherboard power connector

You will need the following parts:

  • 5x M3 6mm female-female nylon posts

Alternatively, you can use 5x M3 nuts.

  1. Add female-female posts to secure the first two screws related to the floppy tray

You will need the following parts:

  • 2x M3 16mm female-female nylon posts

  1. Add the other female-female post related to the floppy tray and the remaining posts on the right side of the motherboard

You will need the following parts:

  • 1x M3 22mm female-female nylon post
  • 3x M3 45mm female-female aluminium posts

  1. Now that the motherboard is completely secured to the bottom panel, turn the bottom panel and prepare to remove the Blu-Tack

  1. Remove the Blu-Tack from the screws on the bottom side of the bottom panel

  1. Turn the bottom panel and prepare to add the posts required to secure the top panel

You will need the following parts:

  • 3x M3 50mm female-female aluminium posts
  • 3x M3 8mm countersunk torx screw
  • 3x M3 countersunk washer

  1. Add now the posts that will join the top panel to the bottom panel

  1. Install the left, right and rear panels in preparation for the floppy tray insertion

  1. Slide the floppy tray into the left panel and align the floppy tray arms to the previously installed posts

  1. Attach the rear arm of the floppy tray to the matching post using a screw

You will need the following parts:

  • 1x M3 8mm countersunk torx screw
  • 1x M3 countersunk washer

  1. Attach the floppy tray wing to the underlying post using a male-female post

You will need the following parts:

  • 1x M3 20mm male-female nylon post

  1. Hook the optional audio amplifier board to the right panel

The audio amplifier board is a pre-built DC 5V 3W+3W PAM8403-based board with a potentiometer.
You will need to solder XH2.54 male right angle connectors to the board connector footprints (rout+lout, power and L+R input) on the bottom side of the board.

The audio amplifier board is attached to the right panel with the bottom side facing up.
As the right panel is 4mm thick and the audio amplifier board seems to be prepared for smaller panel thickness, you will need to use a countersunk drill to reduce the thickness of the panel in the speaker volume hole to facilitate the attachment of the audio amplifier.

You will need the following parts:

  • 1x Mini PAM8403 DC 5V power audio amplifier board 2 channel 3W+3W with volume potentiometer
  • 1x XH2.54 4p male right angle connector (rout+lout)
  • 1x XH2.54 2p male right angle connector (power)
  • 1x XH2.54 3p male right angle connector (L+R input)

  1. Add a knob to the audio amplifier board potentiometer

You will need the following parts:

  • 1x Machined metal aluminium potentiometer volume knob 20x15mm

  1. Install the front panel and connect the speakers to the audio amplifier board

You will need to build a special cable to connect the speakers to the audio amplifier board.
The audio amplifier board has been fitted with XH2.5 male connectors and the speakers come with JST1.25 female connectors.

You will need the following parts:

  • 1x XH2.54 4p female straight connector
  • 4x XH2.54 female pins
  • about 25cm of 28 AWG wire red (left speaker)
  • about 25cm of 28 AWG wire black (left speaker)
  • about 12cm of 28 AWG wire red (right speaker)
  • about 12cm of 28 AWG wire black (right speaker)
  • 2x JST1.25 2p male plug
  • 4x JST1.25 male pins

Crimping JST1.25 connectors may prove difficult so an alternate option is to buy pre-crimped JST1.25 cables and just crimp the XH2.54 connectors.

  1. Prepare to attach the joystick ports extensions to the front panel

You will need the following parts:

  • 4x 4-40 UNC 5/16 inch (~8mm) screws

  1. Attach the joystick ports extensions to the front panel

  1. Build a DC 5V panel mount barrel connector with cable (if using the dc-adapter in a "panel-mount barrel connector" configuration)

You will need the following parts:

  • 1x 5.5mm x 2.1mm DC power jack socket female panel mount barrel connector 11mm diameter
  • 1x XT30 female connector
  • about 10cm of 20 AWG wire red
  • about 10cm of 20 AWG wire black
  • heat shrink tube red
  • heat shrink tube black

Instead of the XT30 connector you can use any other properly sized and rated connector to decouple the "panel-mount barrel connector" installation from the dc-adapter.
The size of the connector used must allow the insertion of the washer and nut for the female panel mount barrel connector.
Another option is to not decouple the installation and to attach directly the female panel mount barrel connector to the dc-adapter, but that makes it difficult to replace the dc-adapter in case of failure or upgrade.

  1. Temporarily dismount the rear panel and install the DC 5V panel mount barrel connector in the rear panel

  1. Build the BIOS selector panel switch cable

You will need the following parts:

  • 1x miniature toggle switch red MTS-102 on-on SPST 3-pin
  • about 25cm of 24 AWG silicone wire green
  • about 25cm of 24 AWG silicone wire white
  • 1x Dupont female sleeve 2p
  • 2x Dupont female pin
  • heat shrink tube green
  • heat shrink tube black

  1. Install the BIOS selector panel switch in the rear panel

  1. Mount again the rear panel and connect the BIOS selector cable to the motherboard

  1. Prepare the power switch and dc-adapter

Steps 29 to 39 describe how to install the dc-adapter for a "panel-mount barrel connector" configuration.

Please see the MSXmakers! dc-adapter page for further information about the dc-adapter.

You will need the following parts:

  • dc-adapter 1.5-1.6b populated for your configuration
    • For the "inverted-power-barrel" configuration:
      • (1x DC Power Jack, 2.1mm on J1 bottom side)
      • (1x 8p 2.54 female header on J10 bottom side near the amp meter)
      • 3x 6.3mm spade terminals
      • 1x 20cm of 18 AWG silicone wire black
      • 2x 20cm of 18 AWG silicone wire red
      • 3x E0508 bootlace ferrules 0.5mm2
    • For the "panel-mount barrel connector" configuration
      • 1x KF2510 8-pin female connector
      • 3x 40cm of 22 AWG silicone wire black
      • 3x 40cm of 22 AWG silicone wire red
      • 1x 40cm of 22 AWG silicone wire yellow
      • 1x 40cm of 22 AWG silicone wire blue
      • 3x 6.3mm spade terminals
      • 1x 30cm of 18 AWG silicone wire black
      • 2x 30cm of 18 AWG silicone wire red
      • 3x E0508 bootlace ferrules 0.5mm2
    • For the mixed "inverted-power-barrel" and ""panel-mount barrel connector" configuration:
      • (1x DC Power Jack, 2.1mm on J1 bottom side)
      • (1x 8p 2.54 female header on J10 bottom side near the amp meter)
      • 1x KF2510 8-pin female connector
      • 3x 40cm of 22 AWG silicone wire black
      • 3x 40cm of 22 AWG silicone wire red
      • 1x 40cm of 22 AWG silicone wire yellow
      • 1x 40cm of 22 AWG silicone wire blue
      • 3x 6.3mm spade terminals
      • 1x 30cm of 18 AWG silicone wire black
      • 2x 30cm of 18 AWG silicone wire red
      • 3x E0508 bootlace ferrules 0.5mm2

The mixed "inverted-power-barrel" and ""panel-mount barrel connector" configuration supports any of those configurations.
When enabling the "panel-mount barrel connector" configuration of the dc-adapter, solder the 8 power cables (on the top side) to the J10 connector which is closer to the XH2.54 power connectors.

This article describes for now only the "panel-mount barrel connector" configuration, but uses a mixed "inverted-power-barrel" and ""panel-mount barrel connector" dc-adapter build.

  1. Connect the step up board to the dc-adapter

The block terminal has 3 terminals:

  • "+5V" (red wire with a "1" marking): connects to the +5V signal from the power supply in the dc-adapter
  • "VCC" (red wire): connects to the VCC signal in the dc-adapter (when the switch is in the ON position the "+5V" and "VCC" terminals are connected together powering the dc-adapter)
  • "DIS" (black wire): connects to the discharge circuit in the dc-adapter (when the switch is in the OFF position the "VCC" and "DIS" terminals are connected together allowing the controlled discharge of the circuit)

  1. Prepare the dc-adapter tray

Please, follow the dc-adapter tray build instructions to prepare the dc-adapter tray.

  1. If not already done, replace the 45mm post near the coin cell battery with a 25mm post to attach the dc-adapter tray

You will need the following parts:

  • 1x M3 25mm female-female aluminium post

  1. Install and secure the dc-adapter tray to the Omega computer motherboard via a single post

You will need the following parts:

  • 1x M3 8mm countersunk torx screw
  • 1x M3 countersunk washer

  1. Detail of the attachemnt point for the dc-adapter tray

  1. Install the power switch in the rear panel, attach the spade terminals to it, and connect the KF2510 connector to the motherboard

  1. Detail of the power switch and KF2510 connector

There are 3 spade terminals on the power switch:

  • "+5V" (red with a "1" marking): connects to the +5V signal from the power supply in the dc-adapter
  • "VCC" (red): connects to the VCC signal in the dc-adapter (when the switch is in the ON position the "+5V" and "VCC" terminals are connected together powering the dc-adapter)
  • "DIS" (black): connects to the discharge circuit in the dc-adapter (when the switch is in the OFF position the "VCC" and "DIS" terminals are connected together allowing the controlled discharge of the circuit)

  1. Build the cable between the panel mount connector and the dc-adapter

In this case, the cable uses a XT30 male connector to connect to the XT30 female connector on the panel mount barrel connector cable, and a male barrel connector to connect to the dc-adapter female barrel connector in inverse position.

You will need the following parts:

  • 1x 28cm male jack cable adapter plug 5.5 * 2.1mm 18 AWG (pre-built cable with one end loose)
  • 1x XT30 male connector

  1. Install the cable between the panel mount barrel connector cable and the dc-adapter

Connect the cable XT30 male connector to the XT30 female connector on the panel mount barrel connector cable, and the male barrel connector to the dc-adapter female barrel connector.

  1. Detail of the cable installation

  1. Build the cable to bring the audio signal from the Omega multimedia hat to the audio amplifier board

The cable should be about 40cm long to connect the Omega multimedia hat sound pins to the audio amplifier board audio input connector.
The end that connects to the Omega multimedia hat is a Dupont 2-pin female connector ("Gnd" and "Sound" signals), and the end that connects to the audio amplifier board input is a XH2.54 3-pin female connector ("L", "G" and "R" signals). The "Sound" signal is duplicated into the "L" and "R" signals to convert the MSX monoaural audio to stereo.

You will need the following parts:

  • 1x Dupont female sleeve 2p
  • 2x Dupont female pin
  • about 40cm of 26 AWG black wire
  • about 40cm of 26 AWG red wire
  • about 5cm extra of 26 AWG red wire (duplicate audio signal)
  • 1x XH2.54 3p female connector
  • 3x XH2.54 female pins
  • heat shrink tube red

  1. Connect the audio signal cable between the Omega multimedia hat and the audio amplifier board

Make sure that you align the Dupont connector signals correctly: the black wire needs to connect to the "Gnd" pin on the multimedia hat and the red wire to the "Sound" pin.

  1. Detail of the audio signal cable connection on the multimedia HAT

  1. Build the audio power cable for the audio amplifier board

The cable should be long enough (in this case about 18cm) to connect the audio amplifier board power connector to the dc-adapter audio power connector.
Both ends of the cable are XH2.54 2-pin female connectors, but the polarity of the cables is reversed in each end 1.

Looking at the connector from the side without pins visible:

  • the dc-adapter side connector (with a "psu" label on the picture) has the GND signal on the left and the +5V signal on the right
  • the audio amplifier board side connector (with a "amp" label on the picture) has the GND signal on the right and the +5V signal on the left

You will need the following parts:

  • 2x XH2.54 2p female connector
  • 4x XH2.54 female pins
  • about 18cm of 24 AWG silicone black wire
  • about 18cm of 24 AWG silicone red wire

  1. Connect the power cable to the audio amplifier board

Connect the dc-adapter end of the audio power cable to the dc-adapter audio power connector and the audio amplifier board end to the audio amplifier board power connector.
Try to not misconnect the audio power cable ends.

  1. Add cable sleeves to help routing the cables nicely

  1. Connect the keyboard ribbon cable and reset header

If you used a polarized connector for the ribbon cable just align it properly, otherwise make sure that the red stripe of the ribbon cable goes to the left of the connectors looking at the boards from the top.
The reset header is not polarized so it can be installed either way.

  1. Detail of the keyboard connections

  1. Align and place the keyboard panel on top of the computer case

  1. Connect the floppy power cable

You will need the following parts:

  • 1x 4-pin floppy power cable

Attention must be paid to the orientation of the cable on the dc-adapter side as the pin header is not polarized.
If you look at the dc-adapter from the top, the floppy power cable should be inserted into the dc-adapter floppy power connector with the connector pins visible on the top.

  1. Detail of the floppy power cable connection

  1. Place the top panel on top of the computer case and secure it with screws

You will need the following parts:

  • 4x M3 14mm countersunk torx screw
  • 4x M3 countersunk washer

Note that there's a missing screw in the picture ;)

  1. Secure the keyboard panel to the bottom panel with screws

Silicone washers are added to account for the inclination of the screws in relation to the bottom panel.

You will need the following parts:

  • 4x M3 8mm countersunk torx screw
  • 4x M3 countersunk washer
  • 4x M3 silicone washers

  1. And... enjoy!

Footnotes

  1. As the connectors are polarized and the signals are crossed between the ends, there's no risk of damaging the audio amplifier board even if the wrong end is connected to the wrong board, but the wire colors will not match the expected signals. ↩