Hi everyone,

If anybody is interested I have some RTL logic kits that I have made. Each kit is £3 and the relevant document can be found on my website under the RTL kits. They compose of the discrete components and a low cost PCB board. Useful for understanding how logic gates work, solder practice etc..

The kits are as follows:
AND Gate
XOR Gate
OR Gate
NOT Gate
NAND Gate
NOR Gate

ebay link:
http://www.ebay.co.uk/itm/150874040730?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

Just comment for details and PM if you would like one or send an email to mitchelectronics@hotmail.co.uk . Also, if you want multiple boards the P&P is still fixed (no addittional charge). I can do a combined offer for all the kits for only £15 (One free kit)

All kits can be found on my website under products>RTL kits

 

When RTL was king it was the MC700 series, made by Moterola. I had a chance to use a few, but they were on the way out during the 1970's, TTL (7400 series) was already taking over, with CMOS (4000 and 4500 series) only a few years away.

Curious, why are you offering this? I suspect you are using discrete components to build these gates, when basic CMOS is much simpler to use and much more compact.

I have no problems with it, just being nosy.

If you can ever find the literature on the 4500 (real number), it was one of the early CPUs out there. All the data has dried up on it, though you can find an occasional obscure reference to the chip. It was a single bit CPU, and was a precursor to the modern µC of today.

 

Haha love the being nosy!
The RTL kits use BJT's which are not affected by static charge hence zero chance of someone damaging the circuit. The RTL logic is also nice to work with (i think), easier to understand (again i think) and to be honest i just prefer RTL over CMOS logic.

 

Not sure where you got that lore, but BJTs are static sensitive, just not as much as CMOS. The reason RTL was bumped as top dog is it is much more sensitive to interference, such as from a local radio station. The basic gate is a simple transistor amplifier, after all.

To keep the current requirements down they used low voltages. It also kept the wattage requirements down too. Their logic level requirements are a joke, pretty much undefined. When there are hundreds or thousands of gates they surge on current, depending on the requirements.

TTL was much more immune from interference, and drew constant currents no matter what logic level they were. They also were able to hit MSI (Medium Scale Integration) with the family (RTL was pretty low scale).

CMOS got rid of all the regulated power supply requirements, has really good noise immunity (logic levels are defined by ½Vcc), and draws almost no current. There is no contest which one works better for me.

 

Sounds like i also need to make CMOS logic kits too

 

Don't be afraid to experiment or have fun with mixing and matching. You will find many people have these dire predictions how one logic family won't work with another, when in truth if you pay attention they mix just fine.

The logic family that makes me nuts is ECL, which is derived from differential amplifiers of all things. They are fast, incredibly so, but they run hot. The family tends to be on the bleeding edge (something like leading edge, only you cut yourself more) of speed. When you have a really high speed application such as lightwave where the speeds can go up to 40Gigabit or higher there is likely ECL in the front end. Problem is, a logic 0 is a -0.7VDC, and a logic 1 is -2.0VDC. It can be mind twisting if you aren't used to it.

ECL only use is speed above all other considerations, as soon as they get speeds down the logic family is shifted into something more common, such as high speed CMOS. ECL is the one logic family I can say I NEVER use.

So what does the RTL kits look like? Have any pictures?

Ever use the kits that are usually labeled X in 1 ( as in 75 in 1 Electronic Projects)? They use the little springs that you insert a regular (usually tinned) piece of wire into. I suspect you could have fun with a home brew version of those.

 

Homebrew spring kit thing...
I had several of those as a child but they did not get me interested in electronics. I got my passion of electronics through a lady who gave me a magazine.

Here is an image of an unconstructed kit:

 

You might consider a flip flop, maybe a 4 bit counter. BG Micro is selling a pack of 1000 PN2222 (unmarked, mfg markings) for just under $4.

 

thanks, thanks and double thanks