[GreenKeys] Data Technology Associates DT500 and DT600

[John, W9DDD]

Good afternoon all,

Taking a break from repairing my paper shredder.

I'm doing some downsizing.  Going through boxes of stuff that hasn't 
been opened of 20 years or more.

So in one of the boxes I find a Data Technology Associates DT500 with no 
documentation pf course.  I can find the schematic of the DT600 on 
rtty.com, but not the DT500.

Also in the same box was a similar size board, a DT600, right, no.  It 
has 5 torroids and the DT600 only 2.  I built this on a perfboard, I'm 
wondering if I cloned the ST-6 on one board?  I was young and could see 
what I was doing back then.

Again, RTTY.com has a schematic, but the quality isn't that great.  But, 
I can see that the ST-6 had 7 op amps and I only have 4 on mine.  Of 
course I may have left off the autostart part and that would make sense.

Any help finding either the DT500 schematic or a better one of the ST-6 
would be appreciated.  I'm going to start looking through the RTTY 
Journal archives but not sure which year to start with.
-- 
John, W9DDD