Summary of ALTAIR 8800 AGAIN PROJECT
This article introduces Dirk's "Altair 8800 Again" project, a retro computer simulator featuring a laser-cut front panel. The design utilizes multiplexed switches and addressable LED strips instead of discrete LEDs for easier customization and installation. While the simultaneous LED updates differ slightly from the original hardware, the build offers a flexible middle ground between full PCB clones and Raspberry Pi setups, suitable for connecting to SIMH or simulating the CPU with a Teensy.
Parts used in the Altair 8800 Again:
- Laser cut front panel
- Multiplexed switches
- Addressable LED strip
- Teensy (for CPU simulation)
- Arduino (alternative small CPU)
- SIMH software (running on PC)
[Dirk] posted a video (you can see below) titled, “Mystery Retro Project Start.” That turned out to be the first of a multipart series on his Altair 8800 Again simulator. The front panel appears to be laser cut and in some future video episodes, we expect to see him simulate the CPU with a Teensy.
There have been plenty of 8800 clones ranging from projects that recreate the original PCBs, to those that just run a Raspberry Pi inside. The middle ground will use an Arduino or some other small CPU to simulate the 8080 CPU.
The switches are multiplexed which isn’t uncommon. However, the LEDs are actually an addressable LED strip. We’ve built a similar panel with discrete LEDs and we can attest that using the strip is going to be easier. Besides that, it allows you to change the LED color to suit your decor, something the old 8800 could not do without a soldering iron.
The downside, of course, is that you can update the LEDs at exactly the same time. For most things that’s probably not going to matter much, but it is still a little bit of a departure from the original computer.
Even without emulation, this would be a good start for a panel to connect to SIMH running on a PC. The use of the LED strips and the laser cutter make this a lot easier than most other builds we’ve seen.
We always think about the Altair around the end of the year since the original showed up in the January 1975 edition of Popular Electronics (which would be on newsstands in December).
If you don’t have the patience to build a full front panel, you can put it on a PCB instead. In fact, we’d be tempted to build a series of PCBs to mount behind the panel. We’ve seen that approach a few times before.
Source: ALTAIR 8800 AGAIN PROJECT
- How does this project simulate the CPU?
The creator expects to simulate the CPU using a Teensy in future video episodes. - What type of lighting is used for the indicators?
An addressable LED strip is used instead of discrete LEDs. - Can the LED colors be changed?
Yes, the addressable strip allows users to change the LED color to suit their decor without soldering. - Does the LED update timing match the original?
No, the LEDs update at exactly the same time, which is a departure from the original computer. - What is the benefit of using an addressable LED strip?
It is easier to use than discrete LEDs and allows for color customization. - Can this panel connect to existing software?
Yes, it serves as a good start for a panel to connect to SIMH running on a PC. - What alternative construction method is suggested if building a panel is too difficult?
You can put the components on a PCB instead. - When was the original Altair shown in Popular Electronics?
The original showed up in the January 1975 edition, which appeared on newsstands in December.
