Recent Posts

Site Info

Authors
  • H.Koenig
  • Dave Greene

« New Period 2 and 4 Wicks | Main | Life Digits »

2007 March 03

Logic Elements
New Herschel Conduit Discoveries

2007-03-03-H-to-Boat.rle
Herschel-controlled glider demultiplexer
Brice Due, 23 August 2006
Last August, Brice Due ran some interesting searches with Paul Callahan's catalyst search program, ptbsearch. His first discovery was a compact 'demultiplexer' -- a Herschel-to-boat converter where the boat can be used to reflect a glider. Unlike previously known Herschel-to-boat converters, the glider has a clear path through the circuit if the boat is not present:

2007-03-03-Herschel-F171.rle
F171 Herschel conduit discovered by Brice Due on 31 Aug 2006
The next discovery was a previously unknown F171 Herschel conduit -- the first new addition to the elemental Herschel conduit list in almost eight years:

2007-03-03-HtoG22NWpath18.rle
glider #22: Brice Due, 2 September 2006
Another unrelated ptbsearch discovery was a Herschel-to-glider converter, #22, with a new output lane:

2007-03-03-Herschel-F171osc.rle
oscillator-supported versions of Brice Due's F171 conduit --
sparks in several possible locations suppress an extra blinker
The base F171 conduit consists of just three eaters, and in this form is unusually slow to recover (it takes 227 ticks before a second Herschel can follow the first.) It is possible to improve the recovery time to 120 ticks with any of a number of oscillators to suppress the transient blinker -- plus an extra eater to suppress the glider that ordinarily removes the blinker. Here are p2, p3, p5, p7, and p15 variants of the F171:

The F171 also produces an extra glider, making it H-to-G converter #23.

2007-03-03-HtoG24SEpath15.rle
glider #24: boojum cleanup of converter by Paul Callahan, 1996
A few more miscellaneous H-to-Gs have also been added to the revised H-to-G collection (not related to recent ptbsearch searches). H-to-G #24, like #21, is a foray into composite technology; a "dirty" H-to-G converter discovered by Paul Callahan leaves an extra block which can be cleaned up by a boojum reflector:

2007-03-03-HtoG25SEpath18.rle
glider #25: boojum cleanup of alternate dirty converter
Like #24, H-to-G #25 is a "dirty" conduit that requires an extra cleanup step, and it uses the identical boojum reflector to do it -- but its output glider and block appear in different places:

A glider following on the same path as #24's output glider would not hit the extra block; in fact, if the first block-suppressing eater is removed, the glider misses both blocks. In #25, by contrast, the following glider cleanly annihilates both blocks. This converter, without the boojum reflector, provides the timing adjustment in the p103079214841 oscillator from Golly 1.1's pattern collection.

Posted by Dave Greene on 2007 March 03 02:43 |