To preface, I'll say that my Binary to BCD Decoder came together quite quickly compared with the display mechanism, which I intended as an afterthought. The display soon grew to a monstrosity, and the engineering of it was rife with difficulties associated with the 240 generation shift caused by the nibble-based positioning of the result from the BCD Decoder. I'll try to cover each of the modules in enough detail to make the whole understandable. There are a number of JPEGs in the zip to serve as visual aids.

See holding.jpg.

In BLUE, PM2ring's Collatz Sequence Generator is amply described by the creator. Above it, in RED is a mechanism to place the output of the Collatz generator in stasis. Collatz term generation is at p7680, whereas BCD conversion is 7680 per nibble. Fortunately, the Collatz generator regards a zero argument with no result and remains stable.
At right, a latch is set by a p1920 gun once data is output from the Collatz generator. This creates a diverting stream that will place the next collatz term in a holding pattern until the BCD mechanism calls for the next term. Up left then right to LWSS up, 90 degrees to LWSS left, 90 degrees down to LWSS Sniper at p3840, the next term cycles through the loop. When the end process signal is received from the BCD converter (shown at upper right), a p3840 one shot latch is set. Its LWSS output sends a glider down to reset the latch, allowing the next collatz term through to both the collatz generator and the BCD converter.

See lowerright.jpg

Lot going on here, though fairly simple until the top. From the BCD converter, data as LWSSs, right in GREEN at bottom, is heisenburped up right into an eight digit nibbler, in ORANGE. This one uses the same basic parts as the one in the BCD decoder, but uses MWSSs and heisenburps to provide the gauntlet. End result is a LWSS up proportional @p240 to the length, in digits of the BCD decoder's output.
The data LWSSs continue right into a p60 to p30 converter, yielding digits as 4 bit LWSS bursts of unpacked BCD up @p240.
At center, the BCD converter outputs a master marker up right, in VIOLET. This marker does a number of things:
1) fans down right to pulse a p240 to p960 converter, in VIOLET at right. This pulse triggers a gap 4 which sends MWSSs down to stretch the now p30 digit data from p240 bursts to p960 for entry into the ordinal converter, in BLUE at top.
2) fans again, and continuing up right to reflect around and down left to trigger another p240 to p960 converter, this the one in GREEN next to the 8 digit nibbler, which stretches that output to p960.
3) up left fans again, up right and reflected down left to fire a set/reset p960 gun, in RED, which provides triggers to the ordinal converter in sync with the p960 data from that converter. The output of the 8 digit nibbler converted to p960, up as LWSS in VIOLET, resets the p960 gun. This arrangement has the value added feature of suppressing trailing zeroes in the display modules.
and 4) countinues up left to LWSS left above the ordinal converter to initialize the seven-segment digit display modules.

See 
binary2ordinal.jpg
and
ordinal.txt
for a detailed description of this

See encode.jpg

The output of the ordinal converter perforates the blocking stream of a p30 MWSS gun up (both in BLUE at bottom right). In YELLOW, is the Segment Encoder. Passing below in VIOLET is the master marker from the BCD decoder. It travels up and then left as MWSS to set diverting latches into each of eight segment modules.
The Encoder receives as data, up in GREEN, a MWSS, the output from the ordinal converter. The MWSS deletes gliders from seven blocking streams of the outputs of seven 16 glider memory loops (Paul Rendell's) containing the patterns for the segmenting modules. The seven loops are for center segment at bottom to lower right segment at top. The MWSS reflects 90 degrees to LWSS leftward at top to provide the Ordinal marker, which travels with segment markers leftward to each digit module. The gliders released for each segment move through stacked advancer guns and are collected by a leftward moving p30 LWSS stream @ p60. A little jog down at the tail end aligns everything for the digit diverting mechanisms. Data out shown in GREEN.

See decode.jpg

At bottom left, the master marker, in VIOLET from the BCD decoder, is fanned up right and sets the diverting latch into the decoder, and down left is reflected up left to set a one shot for the current segment mechanism. Seven possible segment data markers, leftward in GREEN from the encoder, divert off a p30 stream from a latch down right and morph up as LWSSs, reflect 180 degrees down, and enter a gauntlet of diverting gliders from the ordinal marker itself. The ordinal marker, left in VIOLET at bottom, is also diverted, is fanned up right to provide the decoding gauntlet, and also down left to reset the diverting latch, allowing the next burst of digit data and ordinal to continue leftward.
The diverted ordinal converts to MWSS up, and seven MW Heisenburps generate gliders to pick off the seven segments in the order 2,4,6, and then 1,3,5 and 7. The resulting markers provide set pulses to the current segment gun.

See segment.jpg

In PINK, the segmenting mechanism is fairly straightforeward. Standing p30 LWSS guns provide the segments, with blocking streams inverted by latches.
Near bottom center, in VIOLET, the master marker sets a p7680 one shot gun, which upon firing, sets four each thin p7680 one shots firing up. These signals are variously fanned out, and provide for both erasure and enabling of new segments, timed so as to have all segments of a given digit generate simultaneously. If a segment enable pulse is received, a boat is created using a mechanism from David Bell's UNIT LIFE CELL. The fanned signal that resets a segments latch will reflect off a present boat and set the latch again for that segment. Eight of these and done!

Whew!
Mark
