The Turbo Entabulator is alive!

admin — Sun, 09 Jun 2013 16:55:07 +0000

I finally got my 3D-printed, fully-mechanical computer running! Go check out the Turbo Entabulator - and then go build your own!

Cray-zy progress! We have a booting system!

admin — Fri, 03 May 2013 02:53:04 +0000

I had gotten bogged down with the data recovery effort from my COS disk pack in the last year (and my day job building slightly more modern supercomputers got a bit busier), but an awesome programmer named Andras has picked up the torch and carried it ridiculously far!

He not only re-wrote all of my disk recovery software to overcome most of the disk corruption, he also reverse engineered the file system and wrote a simulator for an entire data center’s worth of equipment (4 CPU Cray X-MP, with 4 IO Processors, a peripheral expander, printer, wyse 50 terminals, a farm of disk drives and a real-time clock module that apparently uses the AT command set), and actually got the OS to boot! His write-up about his work is pretty awesome: http://modularcircuits.tantosonline.com/blog/articles/the-cray-files/, including code for his simulator.

If anyone has any software for a Cray-1 or Cray X-MP, now is the time to speak up! We’ve got a working system that can run it! Now, to just find the time to get my FPGA version up to speed so I can run this!

A 3D-printable, mechanical stepper

admin — Mon, 15 Apr 2013 23:02:11 +0000

My efforts have slowly been converging on a workable design for a 3D-printable, all-mechanical computer (with an emphasis on the word *slowly*). Inspired by this recent post I saw floating around the ‘net, I thought I would post my most recent attempt at building a fully-mechanical stepping mechanism (to replace the stepper motors used in my FIBIAC project). Eventually I will get around to integrating this with my electromechanical counter so that I have a fully mechanical counting mechanism.

And video!

Loom!

admin — Sat, 03 Nov 2012 21:56:31 +0000

I’ve been reading an awesome textbook on power-loom engineering, and it’s inspired me to try to build my own all-mechanical, jacquard-style punch card reader. I have a small 3-bit version more-or-less working, and up on thingiverse in case anyone wants to build their own. I doubt it will ever happen, but it would be cool to build a super-simplified all-mechanical computer that actually used punch cards. Maybe I could call it “Plan 2.8″ instead? Anyway, eat your heart out steampunk fans!

To the sea!

admin — Sat, 28 Jul 2012 15:46:59 +0000

A project that’s been on my ‘to-do’ list for years now is some kind of autonomous, robotic boat platform. Although I have dreams of crossing the atlantic someday, for now my sights are set on something more local. To that end, I’ve started construction on a small nautical rover. I unfortunately don’t actually know much about boats or robotics in general, and my primary tools are the laser cutter at NYCResistor and my trusty Thing-o-matic 3D printer, so my boat is kind of funny looking. Some preliminary tests have been promising so far though!

The 3D-printed propellers work much better than I expected!

It runs!

admin — Sun, 06 May 2012 03:32:18 +0000

I really wanted to get this thing up and running for the upcoming interactive art show at NYCR.

Behold – the FIBIAC!

I’ll do a full write-up for it soon with some more details.

More progress!

admin — Mon, 30 Apr 2012 00:29:33 +0000

After a tedious afternoon of soldering, I have the three counters needed for this prototype mounted along with corresponding stepper motors and driver circuits. I still need to add a circuit board to the middle layer to connect the upper and lower layers (to connect the counters to both the card reader and the microcontroller used for sequencing). Anyway, a pic of the (rather awkwardly sized) machine so far:

The sound of progress…

admin — Thu, 26 Apr 2012 00:56:51 +0000

I finally feel like I’m starting to make some progress on this electromechanical computer project. Behold! My prototype electromechanical punch card reader!

Progress update on my Cray-1

admin — Mon, 12 Mar 2012 00:48:19 +0000

Despite my lack of website updates, I actually have continued work on my Cray-1 project. In addition to some progress in recovering an operating system for it, I’ll (hopefully) be releasing another hardware update pretty soon. Major new features that seem to be mostly working:

- I/O channels! I actually implemented the I/O channel hardware for the Cray-1. Initially I had just been using memory-mapped hardware for everything, but I’d like to actually use that space for memory in the near future, so I took some time to add real DMA hardware. 12 Input and 12 Output channels (I think they were typically used in pairs as 12 full-duplex I/O channels for connecting devices). As currently implemented, they’re 64-bit I/O ports that can have anything hung off of them. The 64-bit UART the Cray currently uses for I/O, for instance, would be straightforward to connect to a pair of channels.

-New memory controller / arbiter! This goes along with the I/O channels, as I now have 24 I/O channels competing for memory access, in addition to the main memory controller and the Instruction Buffer. For now it’s just a simple priority arbiter, although I intend to make it a round-robin type to make it more useful. I also had to completely mangle the timing of the main CPU memory ‘functional unit’ to support the new arbiter. The performance impact will probably be minimal. Hopefully I can get around to adding a full 4-megaword (32 megabyte) complement of memory to the Cray soon via on-board DRAM.

-New hardware! I retired the Spartan-3E 1600 I had been using (which was too small to support the I/O channel hardware, unfortunately), and moved to a new Spartan-6 LX45t board that Xilinx sent me. This gave me a lot more breathing room for implementing extra features (hopefully including the aforementioned DRAM controller soon), as well as 128MB of on-board DDR3 memory.

-More speed! I’m fortunately much better at RTL design now than when I started this project, so I took some time to look at what the actual critical path was that was holding me back to 33 MHz or so. With a bit of tweaking I’m actually able to get my design to compile for the Spartan-6 at the Cray-1′s original 80 MHz! This is something that had really been nagging me, so I was pretty happy to get that working.

-A new UART! I moved to a new UART from opencores.org that supports RTS/CTS handshaking, so I can get faster data transfers from my main PC to the Cray-1 (115200 kbps for now – I haven’t tried it any faster).

I probably introduced a whole pile of new bugs with my timing fixes (any DV engineers out there looking for a new hobby?), but I was able to write a simple test program that listens on the serial port and echoes whatever I type back to me (running at 80MHz!!).

Let there be blogging!

admin — Sun, 11 Mar 2012 23:34:09 +0000

For the last couple of years I’ve just been using my website to host pages about my finished projects (which typically means 2-3 updates a year, at the most). I do a fair amount of work that either 1) never goes anywhere, or 2) is kind of ‘follow-up’ work on some of my projects that might be interesting to some people (as it turns out people actually read this site occasionally – thanks all you people who have e-mailed me!). I have no idea if I’ll do this with any more regularity than I normally update my site, but we’ll see. On that note, let there be blogging!