NAND madnes

[hanndoddi]

I was looking at this link from last show #137.

This guy must really like NAND gates lol.

http://www.adafruit.com/blog/2013/03/15/nandputer-functionally-complete-and-absolutely-necessary/

Any one know more crasy wire projects like this?

[justanothercanuck]

http://www.bigmessowires.com/bmow1/

Big Mess o’ Wires 1 is an original CPU design. It does not use any commercial CPU, but instead has a custom CPU constructed from dozens of simple logic chips. Around this foundation is built a full computer with support for a keyboard, sound, video, and external peripherals.

[amyk]

Here's another:
http://www.homebrewcpu.com/

But the difference between OP's and all the other TTL CPUs is in its exclusive use of NAND gates; it's BOM diversity reduction taken to an extreme. The Johnson counter sequencer and the general slowness is reminiscent of the CDP1802.

[jcook1979]

Wow, that's cool!  Is a schematic available?

[Rerouter]

its taking De Morgans theorem to its expected outcome, you can make and, or, nor, xor, xnor, not + buffers out of only nand gates, so realistically he is just adding a few additional steps into the loop,

[digsys]

I'd HATE to be working out the sync for propagation delays !! My FIRST computer model I made was in '70-71
There were rows of toggle switches and Leds - 16 Address, 8 Data, Load/Clr/Run/Stop etc.  I loaded the program one line at a time.
There was NO "oops", if you did a wrong load, you started again. The novelty wore off QUICK !! :-)
I've wire-wrapped some pretty big systems, but none that big or messy !!

[Slothie]

In the 80s I built a 6809 based computer using TTL support logic and static RAMS. That was done using  perf board with copper "lands" and the Verowire wiring system. It was mounted in an old PDP8 case/PSU (wish I still had that!!). had a front panel with toggle switches & LEDs, took up 3 eurocards and the front panel stripboard, and I thought there was more wire than feasible. I obviously now see I was hardly trying compared to the efforts of these guys!!

I chucked my system in the mid 90s not realising how much I'd wish I didnt now 

However, I do have a box with 6502's, Z80's and 6809's, RAM chips, 3o pin SIMMS, and about 50 2716 EPROMS.... I think there may be an 8bit micro or 2 in my future.... 

[digsys]

The 6809 was my most favourite CPU for a long time, it was awesome. Tandy released a TRS80 (I think) based on it.
Then just as it was gaining popularity, 16 bits came into production, and it was lost in time. Sure miss it :-)

[Slothie]

The 6809 was my most favourite CPU for a long time, it was awesome. Tandy released a TRS80 (I think) based on it.
Then just as it was gaining popularity, 16 bits came into production, and it was lost in time. Sure miss it :-)

That was the TRS80 "Color Computer". Great machine, very advanced for its time, too expensive to compete with the Commodore 64 and Atari 800 when it came out in 1980 and by 1986 the Atari ST and Amiga blew it out the water despite many upgrades!

[Moshly]

NAND is not that mad   

Back one level ->
http://makezine.com/2006/09/22/homemade-mt15-computer/
Doh: The original page is gone 

And back another ->
http://www.nablaman.com/relay/progress.php

until ->

[digsys]

COOOL, I'd love to see one using watermelons though .. that would be unique

[Markybhoy]

http://youtu.be/n3wPBcmSb2U

[amyk]

http://klabs.org/history/ech/agc_schematics/
All NOR gates.