Two pictures of the mobo side by side, both with kapton tape covering everything other than the flash chip. On the left, the flash chip is populated, whereas on the right it's not

Enabling Intel AMT For BIOS-over-WiFi

Intel ME, AMT, SMT, V-Pro… All of these acronyms are kind of intimidating, all we know about them is that they are tied to remote control technologies rooted deep in Intel CPUs, way deeper than even operating systems go. Sometimes though, you want remote control for your own purposes, and that’s what [ABy] achieved. He’s got a HP ProDesk 600 G3 Mini, decided to put it into a hard to reach spot in his flat, somewhere you couldn’t easily fetch a monitor and a keyboard for any debugging needs. So, he started looking into some sort of remote access option in case he’d need to access the BIOS remotely, and went as far as it took to make it work. (Google Translate)

The features he needed are covered by Intel AMT — specifically, BIOS access over a WiFi connection. However, his mini PC only had SMT enabled from the factory, the cut-down version of AMT without features like wireless support. He figured out that BIOS dumping was the way, promptly did just that, found a suitable set of tools for his ME region version, and enabled AMT using Intel’s FIT (Flash Image Tool) software.

Now, dumping the image could be done from a running system fully through software, but apparently, flashing back requires an external programmer. He went with the classic CH341, did the 3.3 V voltmod that’s required to make it safe for flash chip use, and proceeded to spend a good amount of time making it work. Something about the process was screwy, likely the proprietary CH341 software. Comments under the article highlight that you should use flashrom for these tasks, and indeed, you should.

This article goes into a ton of detail when it comes to working with Intel BIOS images — whichever kind of setting you want to change, be it AMT support or some entirely different but just as tasty setting, you will be well served by this write-up. Comments do point out that you might want to upgrade the Intel ME version while at it, and for what it’s worth, you can look into disabling it too; we’ve shown you a multitude of reasons why you should, and a good few ways you could.

Antique Motherboard Speaks

[Bits und Bolts] has been restoring an old PC motherboard with the infamous bad electrolytic capacitors. The video of his exploits was interesting enough, but pretty standard stuff. What we found interesting though, was an odd feature of the ASUS Bios called “Post Reporter” that let the motherboard speak error codes and status through the external speaker. (Video, embedded below.) We aren’t sure who wanted that, and since we haven’t seen it around lately, we are guessing the answer was nobody wanted it.

We enjoyed watching the PCB rework. Those large internal ground plane layers do make it hard to unsolder and then solder the caps. That makes the job seem deceptively easy. However, if you want to skip to the exotic BIOS, jump to the 8:20 mark.

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Finally, An Open-Source 8088 BIOS

The Intel 8088 is an interesting chip, being a variant of the more well-known 8086. Given the latter went on to lend its designation to one of the world’s favorite architectures, you can tell which of the two was higher status. Regardless, it was the 8088 that lived in the first IBM PC, and now, it even has its own open-source BIOS.

As with any BIOS, or Basic Input Output System, it’s charged with handling core low-level features for computers like the Micro 8088, Xi 8088, and NuXT. It handles chipset identification, keyboard and mouse communication, real-time clock, and display initialization, among other things.

Of course, BIOSes for 8088-based machines already exist. However, in many cases, they are considered to be proprietary code that cannot be freely shared over the internet. For retrocomputing enthusiasts, it’s of great value to have a open-source BIOS that can be shared, modified, and tweaked as needed to suit a wide variety of end uses.

If you want to learn more about the 8088 CPU, we’ve looked in depth at that topic before. Feel free to drop us a line with your own retro Intel hacks if you’ve got them kicking around!

BIOS POST Card Built Using Raspberry Pi Pico

A computer’s BIOS includes basic diagnostic tools for troubleshooting issues. Often, we rely on the familiar beeps from the POST system for this reason. However, error codes are also available via hardware “POST Cards” that were particularly popular in the 1990s. [Mr. Green] has now built a POST card using readily-available modern hardware.

[Mr. Green] built the device to help troubleshoot an x86 based firewall appliance that was having trouble. Like many x86 systems, it featured a Low Pin Count (LPC) bus which can be used to capture POST troubleshooting codes. By hooking up a Raspberry Pi Pico to the LPC bus on the firewall’s motherboard, it was possible to get it to display the POST error codes on some LEDs. This is of great use in the absence of a conventional PC speaker to sound the error out with beeps.

The build can be used for POST-based troubleshooting on any x86 system with an LPC bus. Files are on Github for those eager to replicate the build. We’ve seen similar work before, too. Video after the break.

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Can You Use A POST Card With A Modern BIOS?

[Alessandro Carminati] spends the day hacking Linux kernels, and to such an end needed a decent compilation machine to chew through the builds. One day, this machine refused to boot leaving some head-scratching to do, and remembering the motherboard diagnostics procedures of old, realized that wasn’t going to work for this modern board. You see, older ISA-based systems were much simpler, with diagnostic POST codes accessible by sniffing the bus with an appropriate card inserted, but the modern motherboard doesn’t even export the same bus anymore.

See “out 0x80, al” in there? That’s a POST code being written

Do modern machines even run a POST test at all, or are there other standards? After firing up a Linux machine and dumping the first meg of memory address space, it clearly contained some of the BIOS code. [Alessandro] looked at a disassembly of the BIOS update image and saw a similar structure, with POST code data sent to port 0x80 just like machines of old.

But instead of an ISA CPU bus, we have the Low Pin Count (LPC) bus which is used to hook up the ‘super IO’ functions, controlling things such as fans, temp sensors, and other system management functions. It also serves as the connection for the TPM feature, which usually appears as one of the motherboard connectors intended to be user-accessible. It turns out that POST codes can be accessed from this point with an appropriate POST card that can talk LPC.

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Bringing Up An Old Motherboard Is A Delicate Process

If you were around for the early days of the personal computer revolution, you’ll no doubt recall the excitement every time IBM announced a new version of its beige boxes. For a lot of us, the excitement was purely vicarious, for despite the “personal” moniker, mere mortals could rarely afford a branded IBM machine. But it was still cool to keep track of the latest releases, and dream of the days when cheap clones would make it possible to play.

[Anders Nielsen]’s recent find of an original IBM Model 5160 motherboard sort of echoes that long-ago excitement, but in a different way. This board, from a PC XT built in 1984, was in unknown condition upon arrival, so [Anders] set about a careful process to try to bring the board back to life. A quick visual inspection leaves one with a sense of both how much things have changed, and how much they’ve stayed the same. Aside from the big 40-pin DIP 8088 CPU and the BIOS ROMs, the board is almost completely populated with discrete logic chips, but at the same time, the basic footprint of a motherboard has changed very little.

The bring-up process in the video below includes checks of all the power rails for shorts, which ended up being a good call — drat those tantalums. After fixing that issue, [Anders] had a bit of trouble getting the board to POST, and eventually resorted to dumping the BIOS ROMs and inspecting the contents. One of the chips had picked up a case of the scramblies at some point, which was easy enough to fix thanks to images of the 5160 ROMs available online. We thought the trick of using a 64k ROM and just writing the BIOS image twice was pretty clever.

In the end, the board came up, although without video or keyboard — that’s for another day. Can’t find your own PC XT motherboard to play with? Then maybe you can just build one.

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Screenshot of the EFI shell, showing doom.wad and doom.efi in 'ls' command output, and then doom.efi being loaded

DOOM? In Your BIOS? More Likely Than You Think!

We’ve seen hackers run DOOM on a variety of appliances, from desk phones to pregnancy tests. Now, the final frontier has been conquered – we got DOOM to run on an x86 machine. Of course, making sure we utilize your PC hardware to its fullest, we have to forego an OS. Here are two ways you can run the classic shooter without the burden of gigabytes of bloated code in the background.

[nic3-14159] implemented this first version as a payload for coreboot, which is an open-source BIOS/UEFI replacement for x86 machines. Some might say it’s imperfect — it has no sound support, only works with PS/2 keyboards, and exiting the game makes your computer freeze. However, it’s playable, and it fits into your BIOS flash chip.

But what if your computer hasn’t yet been blessed with a free BIOS replacement? You might like this UEFI module DOOM port instead, originally made by [Warfish] and then built upon by [Cacodemon345]. To play this, you only need to compile the binary and an UEFI shell, then use the “Load EFI Shell” option in your UEFI menu – something that’s widely encountered nowadays. This version also lacks sound, but is a bit more fully featured due to all the facilities that UEFI provides for its payloads.

Of course there’s far more efficient ways to slay demons on your computer, but even if they aren’t necessarily practical from a gaming standpoint, these two projects serve as decent examples of Coreboot and UEFI payloads. BIOS replacements like coreboot take up so little space, we’ve even seen Windows 3.1 fit alongside coreboot in the BIOS chip. Wondering what UEFI is, even? Here’s a primer for you. And, if you don’t mind the exceptional bloat of a stripped-down Linux install, here’s a Linux image built from the ground up to run DOOM specifically.

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