A CH341 programmer dongle with a stack of adapters on top (one for 1.8V and one for clip connection), and a test clip to the right of it

BIOS Flashing Journey Writeup Puts Tutorials To Shame

December 26, 2021 by Arya Voronova 18 Comments

A couple of weeks ago, [Doug Brown] bought a Ryzen motherboard, advertised as “non-working” and discounted accordingly. He noticed that the seller didn’t test it with any CPUs old enough to be supported by the board’s stock BIOS revision, and decided to take a gamble with upgrading it.

Not having a supported CPU in hand either, he decided to go the “external programmer” route, which succeeded and gave this board a new life. This is not why we’re writing this up, however. The reason this article caught our eye is because [Doug]’s research leaves no stone unturned, and it’s all there to learn from. Whether through careful observation or thorough research, this article covers all the important points and more, serving as an example to follow for anyone looking to program their BIOS.

For instance, [Doug] correctly points out a design issue with these common programmers resulting in 5 V getting onto the 3.3 V data lines, and fixes it by rewiring the board. Going through all the letters in the ICs part number, something that many of us would dismiss, [Doug] notices that the flash chip is 1.8 V-only and procures a 1.8 V adapter to avoid the possibility of frying his motherboard. After finding out that the 1.8 V adapters don’t work for some people, he reverse-engineers the adapter’s schematics and confirms that it, indeed, ought to work with the specific parts on adapter he received.

Noting another letter in the part number implying the flash chip might be configured for quad-SPI operation, he adds series resistors to make sure there’s no chance of the programmer damaging the BIOS chip with its hardwired pinout. This is just an example of the insights in [Doug]’s article, there’s way more that we can’t mention for brevity, and we encourage you to check it out for yourself.

With this level of care put into the process, it’s no surprise that the modification was successful. The kind of inquisitiveness shared here is worth aspiring to, and writeups like this often surpass general-purpose tutorials in their insights and usefulness. What’s your “successfully making use of something sold as non-working” story?

If you’re looking for other insightful BIOS stories, we’ve covered someone reverse-engineering their BIOS to remove miniPCIe card whitelisting. We’ve typically covered BIOS modification stories in laptops, since there’s more incentives to modify these, but a lot of laptop BIOS articles will apply to desktop motherboards too, such as this supervisor password removal story or this LibreBoot installation journey by our own [Tom Nardi].

Thank you [Sidney] for sharing this with us!

An All In One Cube PC For A 1990s That Never Quite Happened

December 20, 2021 by Jenny List 12 Comments

When a particular device or appliance is evoked, there comes with it a set of expectations over what it might look like. A toaster, a camera, a washing machine, or a PC, will all have their own accepted form factors, and it’s rare that a manufacturer is adventurous enough to venture outside them. In the world of PCs there was a brief flowering of this type of creativity through the 1990s, and it’s that time which [ikeji]’s cube PC squarely fits in. It’s a 3D printed PC with a built-in display, keyboard, and printer, and while some might categorize it as a cyberdeck we’d say it goes further, we could easily imagine a slightly more polished version being an object of desire back when a powerful machine carried an 80486.

Inside it’s no slouch, packing an AMD Ryzen 7 Pro on a Mini-ITX motherboard, and while the display is a mere 7-incher it fits neatly behind the fold-down keyboard. The thermal printer is maybe more of a toy, but it’s good to find that even a bleeding-edge motherboard still has a serial port on it somewhere that it can talk to.

While the build undoubtedly has a few home-built rough edges we like the idea, echoing as it does those all-in-ones from the CRT era. Unless you have a handy Minitel terminal you won’t find much like it.

the SoM module used to power a Dell Mini 1210, in an extended SODIMM form-factor

When Dell Built A Netbook With An X86 System-on-Module

December 18, 2021 by Arya Voronova 33 Comments

Just like with pre-touchscreen cellphones having fancy innovative features that everyone’s forgotten about, there’s areas that laptop manufacturers used to venture in but no longer dare touch. On Twitter, [Kiwa] talks a fascinating attempt by Dell to make laptops with user-replaceable CPU+RAM modules. In 2008, Dell released the Inspiron Mini 1210, with its CPU, chipset and RAM soldered to a separate board in an “extended SODIMM” form-factor – not unlike the Raspberry Pi Compute Modules pre-CM4! Apparently, different versions of such “processor cards” existed for their Inspiron Mini lineup, with varying amounts of RAM and CPU horsepower. With replacement CPU+RAM modules still being sold online, that makes these Dell netbooks to be, to our knowledge, the only x86 netbooks with upgradable CPUs.

You could try and get yourself one of these laptops or replacement CPU modules nowadays, if you like tinkering with old tech – and don’t mind having a subpar experience on even Linux, thanks to the Poulsbo chipset’s notorious lack of openness. Sadly, Dell has thoroughly abandoned the concept of x86 system-on-module cards, and laptops have been getting less modular as we go – we haven’t been getting socketed CPUs since the third generation of mobile Intel boards, and even RAM is soldered to the motherboard more and more often. In theory, the “CPU daughterboard” approach could improve manufacturing yields and costs, making it possible to use a simpler large board for the motherboard and only have the CPU board be high-layer-count. However, we can only guess that this wasn’t profitable enough overall, even with all the theoretical upsides. Or, perhaps, Google-style, someone axed this project internally because of certain metrics unmet.

If you think about it, a laptop motherboard is a single-board computer; however, that’s clearly not enough for our goals of upgradability and repairability. If you’re looking to have your own way and upgrade your laptop regardless of manufacturer’s intentions, here’s an old yet impressive story about replacing the soldered-in CPU on the original Asus EEE, and a more recent story about upgrading soldered-in RAM in a Dell XPS ultrabook. And if you’re looking for retrocomputing goodness, following [Kiwa] on Twitter is a must – last seen liveblogging restoration and renovation of a Kaypro someone threw out on the curb.

A Well Documented BreadBoard Computer Shows Dedication

December 18, 2021 by Dave Rowntree 11 Comments

These pages have not been exactly devoid of home-built computers, with those constructed on solderless breadboard less frequent, but still not rarities. But what is more of a rarity is this ground-up 8-bit 74xx logic-based computer (video, embedded below) with full source, an emulator, assembler and test suite. [JDH] spent a solid couple of weeks working late into the night to build this, and the results show for themselves.

The new JDH-8 is now a figment of reality.

The architecture is a traditional 8-bit load/store microcoded processor with the microcode stored in easily programmable AT28C64 EEPROMs for ease of tweaking. The address bus is 16-bits, which is quite ample for this, and puts it in line with (admittedly more sophisticated) 8-bit micros of old such as the 6502. There is also a hardware stack, and a discrete-logic ALU as well! Finally, since that wasn’t enough work already, he added in his own discrete logic video controller.

Wise people simulate before prototyping something like this

There are sixteen instructions covering memory access, ALU operations and I/O operations. One of the great things about this project is that [JDH] readily admits the mistakes made along the way, and how the architecture didn’t need to be this complex. One example is that hardware stack wasn’t really necessary as it could just have been implemented in software. Also, due to the implementation, memory accesses were so fast compared with the achievable cycle time, that there really was no point to using load/store architecture at all! Still, [JDH] had fun building and programming it!

It was interesting to see the use of LogiSim-Evolution to debug first a high level model of the architecture and then the translation into TTL chips. This scribe wasn’t aware of that tool (the shame!) but is going to try this out real soon.

All code for the software side of things can be found on the project GitHub. Perhaps the hardware design will appear there as well, be at the time of writing we couldn’t seem to find it.

Can’t get enough breadboard computers? (We can’t) check this out from last year. Stuck for a suitable enclosure for your latest bread breadboard computer? How about a bread bin.

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Implementing A CPU Using 555 Timers And Logic Synthesis

December 17, 2021 by Dave Rowntree 26 Comments

There is many a comment on these here pages along the lines of “Why did you use a microcontroller, when you could just have easily used a 555 timer!” And, yes, we sometimes agree with the sentiment, but when a chance comment seen by Hackaday.io user [Tim Böscke] suggested turning it around and building a microcontroller out of 555 timers, the gauntlet was well and truly thrown down. Now let’s be clear, this is not the first time we’ve come across this idea, there was a breadboard 555 based build ten years ago, but this is the first time we’ve seen it done by leveraging open source synthesis targeting a PCB!

The first logic element was a simple inverter, constructed by tying the TRIGger and THReShold pins together.

LTSpice model of a NAND gate implemented with 555 and diodes

From there it was a simple matter of adding a few diode-resistor networks to the input, to effect a NAND2 gate and a NOR2 gate. Development was speeded up a bit by modeling the logic circuits in LTSpice, to find the best combination of part values. From these simple elements, all further logic functions could be implemented. Next a memory element was needed. As luck would have it, the 555 has a RS flip flop as part of its circuit, fed by dual comparator inputs. All that was needed was to bias the THRS input at Vdd/2 and then feed the data in via a pass transistor, and hey presto! a serviceable, albeit slow latch.

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Homebrew 16 Bit Computer Reinvents All The Wheels

December 3, 2021 by Ryan Flowers 23 Comments

Building your own computer has many possible paths. One can fabricate their own Z80 or MOS 6502 computers and then run a period correct OS. Or a person could start from scratch as [James Stanley] did. [James] has invented a completely unique computer and CPU he calls SCAMP. SCAMP runs a custom OS called SCAMP/os which you can check out in the video below the break.

[James] describes the CPU and computer as purposefully primitive. Built out of discrete 74xx series logic chips, it runs at a fast-enough-for-homebrew 1 MHz. Plus, it has a lot of blinking lights that can’t help but remind us of the original Imsai 8080. But instead of a panel of switches for programming, the SCAMP/os boots to a shell, which is presented through a serial terminal. Programs are written in a bespoke language with its own compiler. The OS is described as a having a Unix-like feel with CP/M-like functionality. That’s quite a combination!

What we love most about the build, other than its clean looks and blinkenlights, is the amount of work that [James] has put into documenting the build both on his blog and on Github, where the source code and design is available. There’s also an open invitation for contributors to help advance the project. We’re sure he’ll get there, one bit at a time.

While [James] is using a Compact Flash card for storage currently we can’t help but wonder if a Cassette Tape storage system might be a worthwhile future upgrade.

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What’s The Deal With UEFI?

November 30, 2021 by Matthew Carlson 98 Comments

It seems like there are two camps, the small group of people who care about UEFI and everyone else who doesn’t really notice or care as long as their computer works. So let’s talk about what UEFI is, how it came to be, what it’s suitable for, and why you should (or shouldn’t) care.

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