Hawk 370 Slotket Breathes New Life Into Intel’s Legendary 440BX Chipset
If you're an enthusiast of a certain age, you may recall that there was a weird diversion between the Socket 7 platform used by the original Pentium and the Socket 370 platform used by the Pentium III. That diversion was Slot 1, an experiment by Intel done for both technical and business reasons. Interestingly, the Slot 1 platform and the Socket 370 platform are not fundamentally different, and in fact use the same chipsets and firmware. Because of this, you can use what is called a "slotket" to install a Socket 370 processor into a Slot 1 motherboard.
This has been done since these platforms were cutting-edge; it's nothing new. What's exciting is that German YouTuber Bits und Bolts, whose work we have featured on the site before, has created a fully custom design for a new type of slotket that supports not only standard Pentium III processors, but also late-era Tualatin chips and even VIA's C3 processors.
See, it was easily overlooked—partially because Intel wanted you to overlook it—but after the Pentium 4 came out, there was another CPU release for the venerable Socket 370 platform. That was, of course, the Pentium III-S, using a die-shrunk core known as Tualatin. These chips have been popular with enthusiasts since their inception because they run high clock speeds with low power, and some have a large 512KB integrated L2 cache. The problem is that Slot 1 motherboards are much more readily available than Socket 370 motherboards because you can simply drop a late-era processor into most Socket 370 motherboards, whereas, without tricks like a slotket, Slot 1 motherboards are limited to rare and expensive CPU cartridges.
It's long been possible to modify a slotket to support a PIII-S CPU, but this is a major hassle that requires significant physical modifications. Alternatively, you can modify the CPU itself, but that's even more dangerous and also ruins compatibility with standard Socket 370 motherboards. Bits und Bolts was tired of this mess, and he has the necessary skills to fabricate a new slotket design, so that's exactly what he's done. Enter the Hawk 370.
This is, according to the YouTuber, the first slotket design for Socket 370/Slot 1 that supports every Socket 370 processor, including Mendocino, Coppermine, and Tualatin designs from Intel, as well as VIA's C3 CPUs. It supports voltages from 2.05V all the way down to 1.3V, and a 133 MHz FSB, which was the fastest officially supported on any Socket 370 chip. It also supports dual-slot systems for Symmetric Multi-Processing (SMP), and best of all, it auto-detects the installed CPU.
Besides these killer features, the Hawk 370 also includes support for one of the coolest retro-mod projects I've seen in a while: the ThrottleBlaster. This is a Turbo circuit based on a Raspberry Pi Pico that includes a four-digit, seven-segment LCD as well as a potentiometer to let you smoothly control the frequency of your CPU. You can cycle through preset frequencies or select a frequency with 1 MHz granularity, allowing you to use the same machine for both late Windows XP/Windows 98 titles and classic DOS games that are notoriously speed-sensitive. This feature isn't integrated into the Hawk 370 directly, but there is a dedicated solder pad on the slotket for the ThrottleBlaster, allowing you to easily add this cool function yourself.
Bits und Bolts isn't quite ready to start selling the Hawk 370 yet, but he has what he considers a final prototype and plans to start having them manufactured by PCBWay soon. This project has been more than a year in the making, and it's exciting to see it finally come to fruition. If you're interested in snagging a Hawk 370 for your retro Pentium III PC, head over to the comments section of the video above and let him know—he needs to gauge demand to figure out how many he should have made. The YouTuber is also soliciting requests for things to test with the Hawk 370, so drop him a comment on YouTube if you have any ideas!
