Thinkpad 701c: Reverse Engineering a Retro Processor Upgrade

thinkpad701

[Noq2] has given his butterfly new wings with a CPU upgrade. Few laptops are as iconic as the IBM Thinkpad 701 series and its “butterfly” TrackWrite keyboard. So iconic in fact, that a 701c is part of the permanent collection of the Museum of Modern Art in New York.

Being a 1995 vintage laptop, [Noq2's] 701c understandably was no speed demon by today’s standards. The fastest factory configuration was an Intel 486-DX4 running at 75 MHz. However, there have long been rumors and online auctions referring to a custom model modified to run an AMD AM-5×86 at 133 MHz. The mods were performed by shops like Hantz + Partner in Germany. With this in mind, [Noq2] set about reverse engineering the modification, and equipping his 701c with a new processor.

thinkpad-brainsurgeryThe first step was determining which AMD processor variant to use. It turns out that only a few models of AMD’s chips were pin compatible with the 208 pin Small Quad Flat Pack (SQFP) footprint on the 701c’s motherboard. [Noq2] was able to get one from an old Evergreen 486 upgrade module on everyone’s favorite auction site. He carefully de-soldered the AM-5×86 from the module, and the Intel DX4 from the 701c. A bit of soldering later, and the brain transplant was complete.

Some detailed datasheet research helped [noq2] find the how to increase the bus clock on his 5×86 chip, and enable the write-back cache. All he had to do was move a couple of passive components and short a couple pins on the processor.

The final result is a tricked out IBM 701c Thinkpad running an AMD 5×86 at 133 MHz. Still way too slow for today’s software – but absolutely the coolest retro mod we’ve seen in a long time.

Delving Into the Design and Manufacture of a Keyboard

home made keyboard

A while back [Dave] decided he wanted to build his own keyboard. [Dave] has no experience in design, or dealing with manufacturing companies, or even sourcing materials – he just wanted to see if he could do it.

That’s the beauty of the DIY world – most of the time, you can do it, you just don’t know it yet. The keyboard is made out of laser cut steel and acrylic sheets. The switches and key caps are Cherry MX Browns, supplied by GONSKeyboards Works. A Teensy 2.0 lies at the heart of the keyboard acting as an HID device, and the whole thing assembled looks pretty slick – but it wasn’t easy getting to that point.

[Read more...]

The Economics of Fuzz Testing with the Intel Edison

edison-cluster

The Intel Edison is an incredibly small and cheap x86 computing platform, and with that comes the obvious applications for robotics and wearable computing. [mz] had another idea: what if the Edison could do work that is usually done by workstations? Would it make economic sense to buy a handful of Edisons over a single quad-core Xeon system?

[mz] thought the Edison would be an ideal platform for fuzz testing, or sending random, automated data at a program or system to figure out if they’ll misbehave in interesting ways. After figuring out where to solder power and ground wires to boot an Edison without a breakout board, [mz] got to work benchmarking his fuzz testing setup.

Comparing the benchmarks of a fuzzing job running on the Edison and a few servers and workstations, calculations of cost-efficiency worked out well for this tiny x86 system on module. For parallelizable tasks, the Edison is about 8x less powerful than a reasonably modern server, but it’s also about 5-8x cheaper than a comparable desktop machine. Although renting a server is by far the more economic solution for getting a lot of computing power easily, there are a few use cases where a cluster of Edisons in your pocket would make sense.

A Clever Cardboard Computer

CARDIAC Cardboard Computer

Back in the 70’s when computers were fairly expensive and out of reach for most people, [David Hagelbarger] of Bell Laboratories designed CARDIAC: CARDboard Illustrative Aid to Computation. CARDIAC was designed as an educational tool to give people without access to computers the ability to learn how computers work.

The CARDIAC computer is a single-accumulator single-address machine, which means that instructions operate on the accumulator alone, or on the accumulator and a memory location. The machine implements 10 instructions, each of which is assigned a 3-digit decimal opcode. The instruction set architecture includes instructions common to simple Von Neumann processors, such as load, store, add/subtract, and conditional branch.

Operating the computer is fairly simple–the cardboard slides guide you through the operation of the ALU and instruction decoder, and the flow chart shows you which stage to go to next. The program counter is represented by a cardboard ladybug which is manually moved through the program memory after each instruction completes.

Even though the CARDIAC is dated and very simplistic, it is still a useful tool to teach how microprocessors work. Although modern processors include multi-stage pipelines, finely-tuned branch predictors, and numerous other improvements, the basic principles of operation remain the same.

Feeling adventurous? Print out your own CARDIAC clone and try writing your first cardboard computer program.

[via Reddit]

Hackaday 10th Anniversary: Quinn Dunki and Veronica

In case you haven’t been reading Hackaday for the last few weeks, we just had an amazing 10th anniversary party in Pasadena this weekend, full of workshops, talks, and a party that reportedly went until four in the morning. One of the amazing hackers we invited to give a talk was [Quinn Dunki], creator of Veronica, the modern 6502 computer stuffed inside an old radio.

We first saw Veronica a few years ago, but [Quinn] figures she’s been building her computer for about five years now. She’s a software developer by trade that decided one day to dip her toes into the murky seas of hardware development and build a computer from the ground up. She chose the 6502 as the brains of her contraption, laid out everything on single-sided boards etched in a kitchen, and connected everything with a backplane. Right now it has a USB keyboard, (technically a PS/2 keyboard with a USB plug), NES controllers, a VGA display, and a monitor and Pong in ROM. [Quinn]‘s goal was to build a computer that could program itself, and after five years, she’s accomplished that goal.

[Quinn] admits her software background was responsible for a few of her admittedly bad design choices; the VGA is generated by an ATMega microcontroller, working under the theory that if she could clock the micro fast enough, she could do VGA. She now believes an FPGA would have been a better choice for video output, but now that the video circuit is done, she probably won’t revisit that problem.

There is one thing missing from Veronica, and something that [Quinn] will be working on in the future: mass storage. Right now every program Veronica can run is either stored in ROM or entered via the keyboard. A hard drive is the next problem to solve, either with an SD card, or a Compact Flash or IDE hard drive.

Building a Retro Computer that Never Existed

VNC ViewerScreenSnapz009

Sometimes you come across a build so far along you wish you could go back and enjoy it just a bit at a time. This C65 build is so far along, it’s like binge watching a retro computer build. One that never actually existed.

Okay, that’s admittedly a bit rash. But technically the C65 (successor to the Commodore C64) never saw its way through development. A good place to start looking in on the build is from the second post way back in March. The FPGA-based project is already looking promising with proof-of-concept display tests. Are we the only ones surprised by the 1920 native display resolution?

Checking back in June we see that there is some software working but a bounty of bugs will definitely keep [Paul] busy for a while. Fast forward to the beginning of September and he’s come full through to getting a network connection up and running.

The Wikipedia page on the C65 gives a good idea of how awesome this would have been back in the day had it actually made it to market. We suppose it joins the Commodore lists of would-haves and should-haves with the likes of the C128.

30 Years later TED finds his voice: A Commodore Story Part II

Commodore v364, a speech powered computer from the 1980s.

[Continued from 30 Years later TED finds his voice: A Commodore Story Part I]

Like parents standing on the porch waiting to see their children off to their first day of school we waited for what comes next in a release to production. Among our children: The C116 ($49 Sinclair killer), the C264 ($79 office computer), and the V364 – The computer with an interactive desktop that could speak (courtesy of [John Fegans] who gave us the lion’s share of what made the C64 software great).

Something happened then, and by something I mean nothing. Nothing happened. We waited to assist in production builds and stood ready to make engineering change notices, and yet nothing happened. It was around this time that [Mr. Jack Tramiel] had left the company, I know why he left but I can’t tell due to a promise I made. Sadly, without [Tramiel's] vision and direction the new product releases pretty much stopped.

What happens when Marketing tries to design a computer: a TED in a C64 case known as a C16

What happens when Marketing tries to design a computer: a TED in a C64 case known as a C16.

Meanwhile in Marketing, someone came up with the idea to make the C264 more expensive so that they could then sell it for a prohibitively high price in. They changed the name, they told us to add chips, and they added software that (at best) wasn’t of interest to the users at that price. They wanted another C64, after all it had previously been the source of some success. Meanwhile the C116 and the V364 prototypes slowly melded into the random storage of a busy R&D lab. We literally didn’t notice what had happened; we were too busy arguing against abominations such as the C16 — a “creation” brought about by a shoving a TED board into a C64 case (the term inbred came to mind at the time).

[Read more...]

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