30 Apr
2012
30 Apr
'12
10:15 a.m.
In our rtl computer the base resistors were 10k. The collector load 1k and a 100k from the
base to a -ve supply. Cant remember what the transistor types were
--
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
"Shoppa, Tim" <tshoppa at wmata.com> wrote:
On 29 Apr 2012 at 18:46, Richard Smith wrote:
This thread reminds me of a computer we built at
school from discrete
transistors. Each transistor was a NOR gate with three resistors on
the base and a collector resistor. All soldered onto squares of tag
board. We put a bunch of them together to build a shift register with
small laps as output. That would be about 1969 or 1970. Does anyone
remember any more? It must have been a published design somewhere.
In the late 60's and 70's, radio shack sold some little one-bit-flip-flop boards
with lamps. Each flip flop was a little square of circuit board.
There may have been other logic functions available one-to-a-board. I'm pretty sure
they were discrete transistors for the most part (even the round package SSI Motorola RTL
typically had two gates or flip flops per package.)
You could buy multiples and configure them as a counter, and I'm pretty sure they
could be wired as a shift register too.
May have been "Archerkit" brand name. Or "Pbox" brand name although
what I remember were not Pbox's but circuit boards.
I tried using websearches to find pictures or docs, but the Googles, they do nothing!
Tim.