TRS-80 Printer "Interface" Cables

[Tony Duell]

> 
> Hello all,
> 
> Can anyone tell me the difference between the two different TRS-80 
> Model 1 Printer Interface Cables?  These are the cables used to connect 

I remember those... I used one for a year on my Model 1 with a CGP115 
printer. The next year I got the EI and a disk drive...

> a Line Printer directly to the expansion bus on a Model 1 without using 
> the Expansion Interface.  They are ribbon cables with a "little black 
> box" midstream containing the printer port circuitry.  The 26-1411 was 
> originally for the LP1 and the 26-1416 was for the LP2.  
> 
> Now, I know that these also worked on subsequent Line Printers, and my 
> understanding was that the 26-1411 worked on most while the 1416 only 
> worked on a few (!) 
> 
> What exactly is the difference?  Does anyone know?  I'm coming into 
> possesion of a LP3, but I only have a 26-1416 cable....  I don't know if 
> this will work (I'm very confused!) 

Firstly a minor quirk. The interface circuit gets its 5V power from the 
printer (pin <mumble> of the Centronics connector. Radio Shack printers 
provide this, some others may not.

Now, IIRC the cable is in 2 parts. A short part which plugs into the M1 
expansion connector, and which includes the interface chips, and a longer 
part that fits onto a card edge on the interface PCB and connects to the 
printer. It's the second part that's different between the 2 cables I 
think. One of them has a normal 36 pin Blue Ribbon connector, the other 
has an edge connector. You have to use whichever one fits your printer.

-tony