- I would strongly suggest comparing the parts you received with the list below. Let me know if you’re missing anything and I will send a replacement.
- 1 x PC Board
- 36 x 5mm Red LED
- 36 x 12mm LED Standoff
- 36 x NPN Transistor
- 36 x 150Ω Resistor
- 36 x 10kΩ Resistor
- 17 x Mini Toggle on-off
- 8 x Mini Toggle (on)-off-(on)
- 1 x 470Ω Resistor
- 1 x 47µF Capacitor
- 2 x 1kΩ Resistor
- 2 x 0.1µF Capacitor
- 1 x Pre-programmed Arduino Due
- 1 x Front Panel
- 1 x “Altair 8800” Metalic Sticker
- 1 x HC-05 Bluetooth Module or MAX3232 DB9 Serial Module
- 1 x Micro SD Module
- 1 x DC-022 Power jack
- 1 x 12v Power Supply
- 1 x 6 Pin Cable
- 4 x 14mm Standoff
- 4 x 20mm Standoff
- 4 x 3mm Screws
- 4 x 3mm Nuts
- 1 x Dual Pin Header
- 2 x Single Pin Header
- 1 x 6 Pin Female Header
- 1 x 3.5mm Audio Jack
- 1 x USB Cable
- Project Box (optional)
Other Parts You May Need
- Soldering Iron with a nice fine tip
- Good Solder (I recommend Alpha Fry Rosin Core 0.032” Solder)
- Flat Screwdriver
- Phillips Screwdriver
- Needle-nose Pliers
- Side Cutters (Nippers)
- Drill with 3mm or 1/8″ and 12mm or 1/2″ bits
- Micro SD Card (1GB is sufficient)
Your Arduino will arrive pre-programmed, but you may have to upload the software at some point. You can do that by following the instructions on this page.
- Add the 36 150Ω resistors to the top rows under the LED/Transistor pairs in locations R1-R36. Resistors are non-polarized, meaning they can go in either direction, you do not need to worry about orientation.
- The orientation of the transistor is crucial, but relatively simple. Just make sure the flat end of the resistor is facing up, just like the image printed on the circuit board.
- In that bag you will find one electrolytic capacitor and one 470Ω resistor (Yellow, Violet, Brown, Gold color code). If you don’t want to decipher the color code, just know you will find three resistors in the bag, two that match, and one that does not. This is the one that does not match another.
These two components mount in the back (underside) of the PC board in R73 and C1. The orientation of the resistor does not matter, but make sure the short lead of the capacitor (marked with a “-” on the side) goes in the hole also marked with a “-“.
- In the same bag, you will find two 0.1 µF capacitors (marked with “104”) and two 1kΩ resistors (Brown, Black, Red, Gold).
- Those can be mounted on the front of the PC board in R74, R75, C2, and C3 on the lower right side of the board. The orientation of the components does not matter.
- Use your side cutters to clip the single pin headers into 5 segments of 8 pins, and 1 segment of 10 pins to mount the Arduino board. Also clip the double header to a 36-pin (2×18 pin) header.
- Add the male headers to the underside of the PC board. You can also add the six-pin female header for the SPI connector on the Arduino. Make sure you add these to the correct side of the board because desoldering 92 connections would not be fun!
- Solder the headers carefully. Make sure they are as close to vertical as possible, and make sure the solder flows completely over the connection. Most problems happen here with cold solder joints, or solder bridges.
- After you’re done soldering the headers, try putting the Arduino in place and check for a secure fit. Remove it when you’re done.
- Put all the switches in place without soldering them. Blue (two position) on the top row and the power switch location, Red (three position momentary) on the bottom row.
- Put the front panel in place to hold the switches in the correct position (having all two-way switches in the down position makes this easier.)
- Just like the switches, put the LEDs and spacers in place and do not solder them You do ot have to do them all at once, it may be easier to do them in two or three groups.
The orientation if the LEDs is crucial. Make sure the long lead of the LED is toward the bottom of the PC board and the flat side of the LED is toward the top.
- While you are soldering the LEDs, you can verify that the long lead is toward the bottom of the board.
- Make sure you trim the leads after you solder the components. Next we are installing a ribbon cable that could get punctured if you leave the LED or transistor leads untrimmed.
- We’re going to install the six-pin ribbon cable on the underside of the PC board. On the upper side of the board, you can see the labels pictured here.
- This is a good time to test your kit so far. Take the USB cable and plug it into the Programming port on the Arduino. Turn the board over (so you’re looking at the face) and plug the other end of the USB cable into a computer or USB power supply. When the kit is powered, all LEDs will briefly flash, then go dark, and a second or two later, a random pattern of LEDs will light. My favorite quick-and-easy test is to set SW1 on and lower the AUX1 switch. This will run “Kill The Bit” and you will see LED15 to LED8 light in sequence.
- Here’s a good second test: set all address switches (blue switches) to ON and raise the EXAMINE toggle. All address LEDs (0-15) should light. If not, there is either a problem with that addresses LED or toggle switch.
- Next we’re going to add the Bluetooth module (if you ordered a kit with Bluetooth.) The angled pins on the module are not quite what we want.
- You can now solder the Bluetooth module to the underside of the PC board.
Installing the Bluetooth module is certainly simpler than installing the DB9 serial module, because the Bluetooth module fits completely inside the project box.
- If you have chosen the MAX3232 DB9 serial module, solder a four-pin male header to the circuit board, in the middle of the Bluetooth connector (the Bluetooth module uses six pins, solder the header in the middle four pins.) Note: after constructing a few of these, I’d recommend soldering the header on the underside of the PC board (opposite side of what is pictured.) This is to avoid clearance problems with the cable connectors and the front panel.
- Connect to the MAX3232 module to the four pins with the supplied four-pin cable. Note: it is not a “straight-through” connection. The pins are labeled on the PC board and one the MAX3232 module.
- You are basically on your own to find a suitable location to mount the DB9 serial connector. I’ve had the best luck cutting a square hole in the back of the project box on the far right (left if looking at the back) and mounting the DB9 connector vertically. One drawback to this method is you will need a longer four-pin cable to connect the module to the PC board.
- Attach the 14mm standoff to the topside of the circuit board (with male end down) and screw it into the 20mm standoff on the underside of the circuit board.
- Place the front panel in the project case and mark the location of the four holes (I like to use a small drill bit to mark where the holes need to be.)
Drill those holes with a 1/8″ (3mm) drill bit.
- While you’re drilling holes in the project case, drill a 1/2″ (12mm) hole in the lower left area for the DC jack.
Also drill a 1/2″ (12mm) hole a bit left of center for the USB cable.
- Solder a short length of parallel stranded wire from the circuit board (lower left) to the power jack. The square solder pad is for the positive (center pin) wire. The other hole is for ground.
- Plug the Arduino into the circuit board, pass the USB cable through the project box and plug it into the “Programming Port”
When the Arduino is connected to a computer’s USB port, it will draw power from the port and will not need to be connected to a DC power supply.
- Attach the front panel to the topside of the circuit board. Make sure the standoff holes line up, and the LEDs line up with the appropriate holes. You will probably have to apply some force, especially around the threaded switch posts. Add the 3mm nylon screws to keep the front panel in place.
Copy the Altair disk files to an SD card (1MB is sufficient) and install the SD card in the Micro SD card module. The disk images are available here. Put the files in the root of the SD card, do not leave them in the “disks” folder. From your vantage point, the card will appear upside-down.
HINT: If you have loaded the disk images on the card and see nothing but a non-stop sequence of “c” when you access the card, you need to completely reformat the card (FAT32, be sure to select FULL format, not a quick format.) I have run into a couple circumstances where the micro SD card I was trying to use *absolutely* would not work. I don’t know why, but apparently it can happen. Then your only choice is to try a different card.
- Place the front panel/circuit board assembly into the project box. The male ends of the 20mm standoffs should protrude through the holes on the bottom of the project box. Secure it in place with 3mm nuts.
If your case seems a little tight (it’s wood so it tends to expand/contract with temperature and humidity) you can easily trim it a bit with an X-Acto knife.
CONGRATULATIONS! YOUR ALTAIR 8800 IS COMPLETE!