[Coco] Selling my 512k Coco-3 and related items

Stephen Fischer SFischer1 at Mindspring.com
Fri Dec 7 20:19:10 EST 2018

Well after a nap I realized that the first ICs I got were RTL, Resister 
Transistor Logic. I have a book full of them and about 75 Gold plated 
ICs in my parts bin.

Then there was the Transistor Transistor Logic, a book for T squared 
Logic with ~ 100 - 200 ICs of then of various types and then came MOS, 
CMOS, with lots more books and then Linear.

I ordered about 9 books from National and got about four. I drove over 
and was directed to the right building where the lady at the desk told 
me to go through a door which I did. I was then at ground level 
overlooking a huge building that went down about four floors and was 
able almost to allow several 747s to take off at the same time next to 
each other. I got my books but was totally amazed as it was ALL BOOKS.

What totally amazes me is what I used narrow tape laid down on bare 
copper boards to make PCs the experts today are using their computers to 
design CoCos on a chip or other circuits, ordering PC boards to add IC's 
without legs or even getting fully ready to use boards from China in a 
few days.

I remember the first IC a Professor was so proud of as he had put in in 
a circuit with some switches and lights that demonstrated that it was a 
working AND gate. That was the one and only IC at that time in the 
entire Electrical Engineering department of the University of Wisconsin.


On 12/7/2018 3:45 PM, Bill Gunshannon wrote:
> On 12/7/18 4:54 PM, Stephen Fischer wrote:
>> Tie Sync together??????
> That's what I thought, too.  But the picture states that he has HS and
> VS tied
> together run through a resistor connected to the Sync line of an RGBS
> connection.
> He has pictures that seem to show it working, but I don't  know how.
>> The only way is to use an NOR chip, 74??00 if I remember the number
>> correctly. Then if needed to invert the polarity another NOR gate is
>> available on the IC.
> He has an example of such a combiner but claims he didn't need the
> complexity and just used the cable.
> I admit to being baffled.
> bill

More information about the Coco mailing list