30 Apr
2012
30 Apr
'12
12:58 p.m.
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.
30 Apr
30 Apr
1:15 p.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.
2:24 p.m.
On 30 Apr 2012 at 12:58, Shoppa, Tim wrote:
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.)
I suspect that, at the time, (ca. 1968-69), discretes for simple
logic functions had an edge in terms of cost over early integrated
circuit RTL, particularly for an educational product. Perhaps for J-
K flip-flops, the IC version may have had a slight edge.
--Chuck
2:38 p.m.
-----Original Message-----
From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org]
On Behalf Of Shoppa, Tim
Sent: Monday, April 30, 2012 10:59 AM
To: cctalk at classiccmp.org
Subject: Re: discrete transistor computer
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.
Tim:
Look at http://www.radioshackcatalogs.com/
Radio Shack Catalogs from 1939 to 2005
Martin Marshall
4471
days inactive
4471
days old
3 comments
4 participants
participants (4)
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