[GreenKeys] ASR 33 Teletype Question

[Gerald]

Hi Folks
Could you take a look at the photos on my website and let me know what the 
box in the second photo down on the back of this ASR 33 is and what it is 
for? This machine was working when I got it but that was about 3 or 4 years 
ago and once again I do not remember how it was hook up. 
http://www.projectgm.com/html/asr_33.html  I might have ask this question 
before but just don't remember.
Thanks in advance.
Gerald
KD8ENK