WHAT is the difference between TMCC and Legacy?

TMCC is 8 bit computer programming and control whereas Legacy is 9 bit. More data and communications happen such as infrared sensors and more speed steps. TMCC is usally 32 speed steps and Legacy is 200 speeds steps. Finer control and more features that can be accessed using typically the Leagacy remote. The Legacy remote is larger but also has a large LCD information screen and programmable buttons. 

I hope this helps to start.

The biggest difference for people new to the O gauge hobby is that TMCC is no longer being made.  Lionel is only making Legacy control systems and engines.  You can still buy TMCC control systems on the secondary market but there is no guarantee that it will work.

 A person who is considering going from conventional control should only buy Legacy to run Lionel command control engines.  Legacy will run both Legacy and the older TMCC engines without problems.  Some people say that Legacy runs older TMCC engines better than the old TMCC system did.  

I run both systems on my layout.  The only reason that I continue to run TMCC is that I have several TMCC controllers that I bought a long time ago.

NH Joe

Howdy John C.

IMO, Legacy is TMCC on Steroids.   I have Legacy and DCS and I love 'em both for different reasons.

Chief Bob (Retired)

New Haven Joe posted:

The biggest difference for people new to the O gauge hobby is that TMCC is no longer being made.  Lionel is only making Legacy control systems and engines.  You can still buy TMCC control systems on the secondary market but there is no guarantee that it will work.

 

NH Joe

I agree that if you are going to buy a control system then Legacy is the way to go but 3rd Rail and Atlas still produce only TMCC engines.

Pete

Norton posted:

I agree that if you are going to buy a control system then Legacy is the way to go but 3rd Rail and Atlas still produce only TMCC engines.

Lionel still makes a number of TMCC locomotives, especially small motorized units.  Also, many of the command accessories are still TMCC.

tmcc stand for trainmaster command control it is the bases of what cab1 and cab2 work off.

the proper way to call legacy is tmcc2

legacy runs off of a new and improved base compared to the cab1 base.

http://www.lionel.com/products...command-set-6-12969/

http://www.lionel.com/products...command-set-6-14295/

Its development was backed financially by rock and roller Neil Young as part of a partnership between Young and one-time Lionel owner Richard Kughn known as Liontech. Liontech, roughly headquartered on Young's northern California ranch, consisted of a loose confederation of technology developers whom Young had assembled to help develop individual components of the TrainMaster Command system.

Chief among these contributors was Applied Design Laboratories of Grass Valley, California, headed by Atari 2600 co-patent holder Ron Milner. Young had been referred to Milner by his neighbor and friend, Nolan Bushnell, co-founder of Atari. Milner's team (consisting of numerous members, including Robert Johnson and Bryan Scott) developed the main elements of the Command system, including the innovation of using the Lionel steel tubular track system as a broadcast antenna for digital signals overlaying the electrical power being delivered through the track to locomotives, rolling stock and connected accessories.

In their 2006 Volume 2 calalog, Lionel officially unveiled the new TMCCII "Legacy" system. TMCCII promises to revolutionize the way people control and play with their model trains, by adding more features that mimic prototypical operations of a real railroad, and subsequently, a real locomotive. TMCCII is backwards-compatible with existing TMCC modules, and can work simultaneously with CAB-1 controller.

Like TMCCI, the core of the "Legacy" system is the handheld remote. The CAB-2 remote features, among other new functions, a back-lit LCD screen, back-lit LCD touchscreen keypad (which can toggle between numbers and control icons), a Feedback mode (the controller rumbles reflecting the struggling engine), and rechargeable batteries.

copied from other sources.

Thank you bigdodgetrain, I'm a new guy at SD 3 Railers. See you around!

I have a question is tmcc and command control the same. I have a Lionel dash 8 that says command control on the box. 6-18291. This shows to be tmcc in the Lionel catalogue. I’m selling one and I have a buyer that says it’s not equipped. 

I like bigdodgetrain's explanation.  And I believe it's TMCC that is 7-bit and Legacy that is 8-bit.

Legacy will run TMCC locomotives.  And TMCC will run Legacy locomotives, although not with all the Legacy features.

As far as I'm concerned, TMCC is in the technological "sweet spot".  I like it.  I'm sticking with it.

George

@ldodge64 posted:

I have a question is tmcc and command control the same. I have a Lionel dash 8 that says command control on the box. 6-18291. This shows to be tmcc in the Lionel catalogue. I’m selling one and I have a buyer that says it’s not equipped. 

It has TMCC. Send your buyer this link.

https://www.lionelsupport.com/...ents/71-8290-250.pdf

Pete

The TMCC protocol and the Legacy TMCC2 protocols and neither 7-bit, 8-bit, or 9-bit. 

Both protocols use a 24-bit word (three bytes).   The TMCC2 protocol has two formats - single-word commands, and three-word commands.  The TMCC2 three-word commands allow the protocol to be extended for additional Legacy features.

TMCC1 includes engine, train, accessory, and switch commands. 

TMCC2 has engine, train, and Legacy sound, lighting, and effects commands only. 

For single-word commands to engines and trains, TMCC2 mirrors the TMCC1 commands.  The mapping of bits within the 24-bit word is different between the two protocols.  Address bits remain at 7 (1 to 99).  Data bit mapping allows expansion of some data values to 8 bits.  Most importantly, absolute speed control increases from 5 bits (32 steps) in TMCC1 to 8 bits (200 steps) in TMCC2 which allows precise speed control of Legacy engines. 

The TMCC2 three-word commands are used to command Legacy sound cars, station announcements, lighting, and special effects and features available on engines and cars.

When you are controlling your Legacy layout with the Cab2, you are using both protocols.  You have more precise speed control, quilling whistles, special sounds and lighting, and control of unique features like pantographs.

I just purchased a Legacy #990 command set along with an MTH 40-1000 Z-1000 Transformer. Will I need anything else to run my old post war Lionel locomotives? I also plan to run a new Polar Express Lionchief 2.0+ with the same setup. Thank you in advance for any advice as I am sort of new to this. I've had Lionel trains before but older basic sets. Not up to speed with any of the newer tech.

For the Lionchief 2.0+, you'll be fine with your set up.

However, in order to run postwar, you'll need to add a Legacy Powermaster. It allows you to remotely control the level of power that the xformer is feeding to the track.

It connects to a set of the xformer outputs and then connects to the track.

Something that I don't believe has been mentioned yet is a simple clarification.

Many years ago you turned the handle of the transformer, which increased the electricity going to the track, and then the engine began to move accordingly.  However, with the introduction of Lionel's Train Master Command Control (TMCC) system in the mid-nineties (and continued on with the later Legacy system) you now have a remote control that you use to send 'juice' to an engine on the track that has its own unique ID which YOU have assigned to it.  Consequently if your layout is large enough theoretically you could run several engines on the same track by simply keying in the IDs of each engine and running them at the same speed or, while multiple engines are running (whether on the same track or various loops) you can turn 'off' the smoke of one while turning it 'on' for another, merely by punching in the 2 or 3 digit ID number.  Other TMCC or LEGACY features work the same way - you give individual commands to individual engines.

Hope that simplifies the basic concept to you.

To me, legacy is just a complicated TMCC. I'm happy running my two legacy locomotives in TMCC via DCS.

Guide to the original TMCC Command Control set, which was the command base and handheld remote.   Advanced operating techniques,   page 22.   Legacy uses the same commands and command base, supposedly simplified.   

IMO, few operate multiple units, as detailed in the documents, most simply assign each engine, in a consist, (lash-up), the same number, and operate as one engine. 

Atlas SW9 models, with early TMCC, programmed as a consist.  Note: only the front engine, front coupler, and rear engine, rear coupler, function in the pictured consist.  Same applies to head light front and head light back, all other lights are off.

Mike CT. 

The Legacy system is basically a newer and improved version of TMCC with additional features and is backwards compatible with TMCC.

"Command Control" is basically any system by which the operation of the train (speed, horn, bell, whistle, etc.) is controlled remotely as opposed to by the handles/controls of a transformer and would include Lionchief remotes, universal remotes, wi-fi, bluetooth, Cab 1and Cab 2, DCS remotes and app, etc.

Thanks to all for the explanations. I have wondered about the same thing, as I am thinking about upgrading from the old conventional control I currently use. I am not electronically inclined at all, and can barely put a new plug on a lamp cord.

Jeff

One thing that I don't think has been mentioned is that TMCC is one way control, whereas Legacy is two way. What this means is TMCC is blind; when you issue a command there is no confirmation that it was sent or received. You can't even tell if the batteries are dead . Your only indication is what the engine does or doesn't do. With Legacy there is a screen which clearly shows what the engine is doing, and immediately tells you that a command was received. Same with DCS.

None of the above is a detriment really; it's just the difference between older and newer technology. I run both TMCC and Legacy (and DCS) on my layout and it's nice to have extra controllers for visitors to use. The grandkids actually prefer the simplicity of TMCC and the smaller TMCC and DCS handhelds are easier for them to use. All good.

Rod

Just out of curiosity, did Legacy end the signal loss, need for ground planes, and advent of magic boxes to "tune" the TMCC signal for better running of some engines... ala "Dales legacy"  & GRJ's end product he manufactures/sells?

I run TMCC, and have one (and thankfully only one) somewhat cranky engine that periodically will stop & blink it's lights, stutter etc.  Classic TMCC signal issues.  

I often wondered if just buying a Legacy set would end this problem.

Tom

@FlyPlanes-PlayTrains posted:

I often wondered if just buying a Legacy set would end this problem.

Maybe yes, maybe no.  The Legacy command base outputs a signal with almost twice the amplitude of the old TMCC BASE1.  However, there are a lot of people that still need a "boost" for larger layouts for reliable running, especially multi-level layouts.

@Rod Stewart posted:

One thing that I don't think has been mentioned is that TMCC is one way control, whereas Legacy is two way. What this means is TMCC is blind; when you issue a command there is no confirmation that it was sent or received. You can't even tell if the batteries are dead . Your only indication is what the engine does or doesn't do. With Legacy there is a screen which clearly shows what the engine is doing, and immediately tells you that a command was received. Same with DCS.

TRod

Legacy is NOT 2 way communication. The base sends the signal the locomotive does not acknowledge the commands. The only 2 way communication is between the base and the handheld. Some information can be relayed back via the IR and sensor track but not command acknowledgements.  The handheld is not updated by locomotive other than some of the info from the sensor track.

With DCS the TIU sends out a signal and the locomotive replies with an acknowledgement. The locomotive also sends back information about the engine status and track status and updates the handheld.

mowingman - I hear you, I'm the same as you.  A big challenge for me used to be replacing a burned out light bulb in a table lamp (lol).  However, I found it very easy to understand and install the Legacy TrainMaster, Cab-1L & Base-1L - simply by reading the accompanying instructions.  Let me conclude by saying this - I wouldn't go back to the old way of controlling trains, that's for sure!

Good Luck and Happy New Year!

@PH1975 posted:

mowingman - I hear you, I'm the same as you.  A big challenge for me used to be replacing a burned out light bulb in a table lamp (lol).  However, I found it very easy to understand and install the Legacy TrainMaster, Cab-1L & Base-1L - simply by reading the accompanying instructions.  Let me conclude by saying this - I wouldn't go back to the old way of controlling trains, that's for sure!

Good Luck and Happy New Year!

Thanks. It is good to hear that "it is so easy even a child can do it". Will find out pretty soon.

Jeff

@MartyE posted:

Legacy is NOT 2 way communication. The base sends the signal the locomotive does not acknowledge the commands. The only 2 way communication is between the base and the handheld. Some information can be relayed back via the IR and sensor track but not command acknowledgements.  The handheld is not updated by locomotive other than some of the info from the sensor track.

With DCS the TIU sends out a signal and the locomotive replies with an acknowledgement. The locomotive also sends back information about the engine status and track status and updates the handheld.

Well; don't I feel stupid, haha!

Rod

In a quick read of these posts I didn't see anyone mention to the original poster that both systems operate with a constant 18 volts fed to the tracks as opposed to using a transformer which controlled the speed by varying the voltage from below 6v to 18v - 22v. The TMCC/Legacy systems control the voltage remotely through the locomotive.

Neil Young pushed the creating of TMCC so he could share his love of trains with his son who has cerebral palsy. His son could not manipulate the standard transformer controls. That is why the throttle is the large red disc which made it possible for his son to run trains.

TMCC vs Legacy is like riding a horse drawn buggy vs a Mustang.   Well maybe not that extreme, but the features of legacy are amazing and awesome.  Running TMCC engines is much improved, the features of legacy locomotives the best in the industry

@superwarp1 posted:

TMCC vs Legacy is like riding a horse drawn buggy vs a Mustang.   Well maybe not that extreme, but the features of legacy are amazing and awesome.  Running TMCC engines is much improved, the features of legacy locomotives the best in the industry

Thanks! Good to know. I just came across this topic and it is extremely helpful.

Possibly completing the circle of knowledge here...Lionel published the TMCC protocols and let anybody make TMCC electronics. This is why Atlas and others are selling TMCC locos. This decision showed remarkable foresight and IMHO has strengthened the industry and the hobby. One practical aspect of this is that you can buy a TMCC board (from Electric Railroad), with or without railsounds, and make nearly any loco run under TMCC. To me, that is amazing.

Don Merz

Maybe I missed it in this message thread, but you can't mix Conventional locomotives with TMCC or Legacy on the same track, because in TMCC/TMCCII the track must have full power on all the times (16 to 18 volts AC). A conventional locomotive would go to full speed the instant you turn on the transformer on a TMCC layout! Kind of important I thought.

To clarify, I can run both TMCC and Legacy engines using my 990 Legacy system, right?

@WesternPacific2217 posted:

Maybe I missed it in this message thread, but you can't mix Conventional locomotives with TMCC or Legacy on the same track, because in TMCC/TMCCII the track must have full power on all the times (16 to 18 volts AC).

Since the original query was the difference between TMCC and Legacy, one could assume they understand that point, and were really looking for what Legacy brings to the party over TMCC.  Since the OP already runs DCS, I suspect he gets the distinction between command control and conventional operation.

Never used a conventional transformer since returning to the hobby but I do love the Legacy system.

Western,

You're correct.  You can run multiple command control locomotives on the same stretch of electrically-connected track, which is usually fed, 99.999% of the time, with a constant AC voltage of around 18 volts.  Because of this constant source, at 18 VAC, once you add a conventionally-controlled loco to this stretch it will accelerate out of control as soon as the power is turned on.

However if you're sneaky you'll be able to get the conventional loco to run with them, under some semblance of control (very limited), if you power the stretch up first to something less than 18 volts, say 10 VAC, and get the conventional loco rolling.  More specifically pick a voltage at which the conventional loco runs but does not fly off the rails.

Then introduce one or more command control locos.  As long as the track voltage is high enough, even though it's not 18 VAC, they will run OK.  If you decide however to lower it too low, say to tweak the speed of the conventional unit downward, at some point command control will cease to function predictably.

Obviously this works best if you have a circle or oval of track, and can route the command equipped locos into it it from a siding via a track switch once you have the conventional unit running to your satisfaction.

I've done this before, just to see what would happen.  Is it satisfying? Definitely not--there's very limited range of voltage for which control over the conventional unit is OK before 1.) it flies off the track, or 2.) you lose control of the command units.

Can you do it though?  Yes.

Mike

"TMCC is 8 bit computer programming and control whereas Legacy is 9 bit"

So, Legacy IS a bit better. 

@Edmund Schwartzel 060518 posted:

"TMCC is 8 bit computer programming and control whereas Legacy is 9 bit"

So, Legacy IS a bit better.

Yes, but just a bit.

I own three Lionel locomotives with LEGACY on board, but I operate them with "TMCC I " control gear -- along with two locos equipped with "TMCC I." That works for me.  I also have a Lionel POWERMASTER wired in the track power circuit, so I can operate conventional trains too. I bought that device for use by visitors coming to my layout with their conventional trains.

I toyed with the idea of buying the CAB-1L and its accompanying Command Base, but that extra technology seemed to be of little use on my modest, relatively uncomplicated L-shaped layout. I don't need those benefits. However, I know hobbyists who thoroughly enjoy extending the boundaries of control systems for their layouts. More power to them!

If I was a member of a train club with a large layout and multiple Lionel trains, I'd recommend buying and installing LEGACY gear.  Then I'd convene operating sessions so that members could learn how to use the system to its full potential.

Mike Mottler    LCCA 12394

My layout runs with Legacy and DCS.  I have two CAB2 Legacy remotes, and I also have a couple of the CAB1L remotes for visitors.  I have the MTH TIU wired so I can run conventional or command on the mainline using the DCS remotes (got a few of those as well).

Just drop by my place Mike, I'll get you trained on the Legacy and MTH DCS systems.