Thinkpad 701c: Reverse Engineering a Retro Processor Upgrade


[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.

A PC Engine to TurboGrafx-16 Converter


The PC Engine was pretty popular in Japan, but only the coolest kids in America had the US edition, the TurboGrafx16. These two systems weren’t exactly the same; the TurboGrafx-16’s data bus was flipped so the games were made to be incompatible, and the US games have a region lockout. [Kaz] looked at the existing hacks for running Japanese games on US systems, and every single one of them required modding a console. Thinking he could do better, he came up with the PC-Henshin, an adapter and CPLD that allows Japanese game to run on US consoles.

To take care of the mixed up lines on the PC card connector between the US and Japanese variants, a few adapter cards are available. That’s great, but they only solve one part of the compatibility problem. The region lockout routine found on nearly every American title mean PC Engine consoles can’t run TurboGrafx-16 games. [Kaz] used a small, cheap CPLD to read the data bus, patch everything as it is read out, and turns a Japanese console into something that can play American games.

Video below.

[Read more...]

Build Your Own Retrocomputer with Modern Chips


If you’ve ever wanted to get started in retrocomputing, or maybe the Commodore 64 you’ve been using since the 80s just gave up the ghost, [Rick] aka [Mindrobots] has just the thing for you: a retrocomputer based on a PIC microcontroller and a Parallax Propeller.

The two chips at the heart of the computer are both open source. The Propeller is the perfect board to take care of the I/O, video, and audio outputs because it was purpose-built to be a multitasking machine. The microcontroller is either a PIC32MX150 or a PIC32MX170 and is loaded with a BASIC interpreter, 19 I/O pins, a full-screen editor, and a number of communications protocols. In short, everything you would ever want out of a retro-style minicomputer.

The whole computer can be assembled on a PCB with all the outputs you can imagine (VGA, PS/2, etc) and, once complete, can be programmed to run any program imaginable including games. And, of course, it can act as a link to any physical devices with all of its I/O because its heart is a microcontroller.

Retrocomputing is quite an active arena for hackers, with some being made from FPGAs and other barebones computers being made on only three chips. It’s good to see another great computer in the lineup, especially one that uses open chips like the Propeller and the PIC.

Hackaday Retro Edition: 386 Compaqs

compaq [Antoine] recently learned of a little challenge we have in the hinterlands of the Hackaday webosphere – what’s the oldest, or lowest spec hardware you have that can load this our retro edition? He has a pile of old PCs at his work, and with a lot of idle time at work because of summer, he decided to dig into that pile and get a really old computer up on the Internet.

While the pile of PCs didn’t have anything as old as he was expecting, [Antoine] did find an old Compaq from 1992. It has a 386DX running at 25MHz, 4MB of RAM, a 300 MB hard drive, VGA, and an Ethernet NIC. Gathering the requisite CRT monitor, PS/2 keyboard, and an AUI to a more modern Ethernet connector.

When getting these ancient computer on the Internet, the secret sauce is in the software configuration. [Antoine]‘s box is running DOS 6.2, but was previously configured to connect to a Microsoft filesystem server on boot. This server was probably somewhere at the bottom of the same pile the Compaq was salvaged from, so rolling his own modern networking stack was the way to go. A driver for the NIC was downloaded on another computer and transferred via floppy, as was mTCP, the key to getting a lot of old PCs on the Internet. The browser is Arachne, and with the right configurations, everything worked perfectly.

[Antoine]‘s efforts resulted in a computer that can easily handle the stripped down Hackaday retro edition, and can handle light browsing on Wikipedia. The effective download rate is something like a 33k modem; even with a fast (10M!) Ethernet connection, processing all the packets is taxing for this old machine.

Hackaday Links: August 30, 2014


Adafruit did another Circuit Playground, this time concerning frequency. If you’re reading this, no, it’s probably not for you, which is great because it’s not meant to be. If you have some kids, though, it’s great. Not-muppet robots and oscilloscopes. Just great.

The Hack42 space in Arnhem, Neterhlands recently got an offer: clean out a basement filled with old computer equipment, and it’s yours. Everything in the haul had to fit through an 80cm square door, and there are some very heavy, very rare pieces of equipment here. It’ll be a great (and massive) addition to their museum. There’s a few pics from the cleanout here and here.

[Mike] has been working on a project to convert gerber files into SVGs and it’s great.

[Carl] did a roundup of all the currently available software defined radios available. It’s more than just the RTL-SDR, HackRF, and BladeRF, and there’s also a list of modifications and ones targeted explicitly to the ham crowd.

This is a Facebook video, but it is pretty cool. It’s a DIY well pump made in Mexico. A few rubber disks made out of an old inner tube, a bit of PVC pipe, and a string is all you need to bring water to ground level.

What can you do with a cellphone equipped with a thermal imaging camera? Steal PIN codes, of course. Cue the rest of the blogosphere sensationalizing this to kingdom come. Oh, what’s that? Only Gizmodo took the bait?

About a year ago, we saw a pretty cool board made by [Derek] to listen in on the CAN bus in his Mazda 3. Now it’s a Kickstarter, and a pretty good one at that.

Your connectors will never be this cool. This is a teardown of a mind bogglingly expensive cable assembly, and this thing is amazing. Modular connectors, machined copper shields, machined plastic stress relief, and entire PCBs dedicated to two caps. Does anyone know what this mated to and what the list price was?


iPad Finds New Home in Mac Classic

Who of us out there don’t have a spare iPad and Mac Classic kicking around? If you are one of those lucky folks then this project is for you. [site hirac] has made a pretty neat stand for an iPad made out of a Mac Classic case (translated). It just happens that the screens of the Mac Classic and iPad are pretty darn close in size. Although the screen size is similar, the resolution is not. The original Macintosh Classic had a black and white screen with a resolution of 512 × 342 pixels. The iPad’s resolution of 1024 x 768 pixels has 450% more pixels than the original Mac.

To get the iPad to fit correctly, the case had to be significantly modified. First, all of the internals of the Mac were removed, leaving just an empty case. The front panel of the case was removed and a slot on the left side is made. This slot helps to allow the iPad to slide into the Mac. On the inside of the front panel quite a few of injection molded supports were trimmed away for clearance. A slot was also cut in the left side of the rear case half. When the case is re-assembled, the slots in the front and rear halves provide a large enough hole for the iPad to fit through. Oddly, there are some plastic features on the front panel that are at just the right height to hold the iPad in the ideal location to line up with the screen cutout in the case.

[Read more...]

The Entire Commodore 64 Library In Your Pocket


[sweetlilmre] is just beginning his adventures in retrocomputing, and after realizing there were places besides eBay to buy old computers, quickly snagged a few of the Amigas he lusted after in his youth. One of the machines that didn’t make it into his collection until recently was a Commodore 64 with Datasette and 1541 drive. With no tapes and a 1541 disk drive that required significant restoration, he looked at other devices to load programs onto his C64.

These devices, clever cartridge implementations of SD cards and Flash memory, cost more than anyone should spend on a C64. Realizing there’s still a cassette port on the C64, [sweetlilmre] created Tapuino, the $20 Commodore tape emulator

The hardware used to load games through the Datasette connector included an Arduino Nano, a microSD breakout board, a 16×2 LCD, some resistors, buttons, and a little bit of wire. The firmware part of the build – available here on the Git – reads the .TAP files off the SD card and loads them into the C64.

[sweetlilmre] posted a very complete build post of the entire device constructed on a piece of protoboard, Pop that thing in a 3D printed case, and he can have the entire C64 library in his pocket.


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