3 ms·

I remember Connection Machines supposedly had an array (well, hypercube) of “one bit processors”. I never knew what that meant. Is this similar?

by timmg 4y ago

kens 4y ago
These are both one-bit processors, but very different. The Connection Machine had a 1-bit ALU and it operated on larger words serially, so to the user it looked like it was doing 32-bit arithmetic (or whatever). The big deal about the Connection Machine is that it had 64K processors operating in parallel, so it formed a massively-parallel supercomputer. The Motorola chip on the other hand was "genuinely" one bit. It was designed for Boolean control applications with one bit values. (You could do serial arithmetic if necessary, but it was very inconvenient.)
- adrian_b 4y ago
  I have programmed once, many years ago, when I had just finished my studies, such an one-bit processor, and I will describe the application, because I suppose that most people now are not familiar with what can such a processor be useful for. That one-bit processor was not made with a Motorola 14500, but it was implemented with a board with TTL integrated circuits, but its architecture was very similar to the Motorola one-bit processor. Actually it was rather the other way around, such programmable one-bit processors made with bipolar ICs had been widespread in the industry before the appearance of microprocessors, and Motorola has attempted to substitute them with a CMOS circuit with higher scale of integration and lower power consumption. That application on which I have worked was in a metallurgical plant where various metal forming processes were done, e.g. metal sheet rolling or metal bar extrusion. Such a huge installation for metal working had many multi-megawatt DC electric motors, whose variable speed and torque were controlled by thyristor converters and hundreds of movable pieces, which were moved hydraulically, so the movements were controlled by opening or closing hydraulic valves. There were also many sensors, some continuous, e.g. measuring the speed of the electric motors, and others discrete. The control unit for the metal working installation was implemented with the logical one-bit processor, together with an analog computer made with operational amplifiers. The analog computer controlled the speed and torque of all electric motors, and all analog sensors were among its inputs. The one-bit processor controlled all on-off devices, i.e. all hydraulic valves and all electromagnetic relays (which enabled the supplies of the hydraulic pumps, of the fans and of the high-power DC electric motors). So the one-bit processor had around one or two hundreds of one-bit logical output variables and a similar number of one-bit logical input variables, all connected by complicated Boolean equations. For both the logical one-bit processor and the analog computer, the inputs and outputs included not only the connections to the metal working installation, but also the keys and joysticks and display devices of the control panel used by the operator of the installation. After cheap microprocessors became available, and also cheaper DACs and ADCs, a single-board computer could be used to do what previously required an entire cabinet with a logical one-bit processor and an analog computer.

I remember Connection Machines supposedly had an array (well, hypercube) of “one bit processors”. I never knew what that meant. Is this similar?

by timmg 4y ago

I remember Connection Machines supposedly had an array (well, hypercube) of “one bit processors”. I never knew what that meant. Is this similar?

kens 4y ago

These are both one-bit processors, but very different. The Connection Machine had a 1-bit ALU and it operated on larger words serially, so to the user it looked like it was doing 32-bit arithmetic (or whatever). The big deal about the Connection Machine is that it had 64K processors operating in parallel, so it formed a massively-parallel supercomputer. The Motorola chip on the other hand was "genuinely" one bit. It was designed for Boolean control applications with one bit values. (You could do serial arithmetic if necessary, but it was very inconvenient.)

adrian_b 4y ago
I have programmed once, many years ago, when I had just finished my studies, such an one-bit processor, and I will describe the application, because I suppose that most people now are not familiar with what can such a processor be useful for. That one-bit processor was not made with a Motorola 14500, but it was implemented with a board with TTL integrated circuits, but its architecture was very similar to the Motorola one-bit processor. Actually it was rather the other way around, such programmable one-bit processors made with bipolar ICs had been widespread in the industry before the appearance of microprocessors, and Motorola has attempted to substitute them with a CMOS circuit with higher scale of integration and lower power consumption. That application on which I have worked was in a metallurgical plant where various metal forming processes were done, e.g. metal sheet rolling or metal bar extrusion. Such a huge installation for metal working had many multi-megawatt DC electric motors, whose variable speed and torque were controlled by thyristor converters and hundreds of movable pieces, which were moved hydraulically, so the movements were controlled by opening or closing hydraulic valves. There were also many sensors, some continuous, e.g. measuring the speed of the electric motors, and others discrete. The control unit for the metal working installation was implemented with the logical one-bit processor, together with an analog computer made with operational amplifiers. The analog computer controlled the speed and torque of all electric motors, and all analog sensors were among its inputs. The one-bit processor controlled all on-off devices, i.e. all hydraulic valves and all electromagnetic relays (which enabled the supplies of the hydraulic pumps, of the fans and of the high-power DC electric motors). So the one-bit processor had around one or two hundreds of one-bit logical output variables and a similar number of one-bit logical input variables, all connected by complicated Boolean equations. For both the logical one-bit processor and the analog computer, the inputs and outputs included not only the connections to the metal working installation, but also the keys and joysticks and display devices of the control panel used by the operator of the installation. After cheap microprocessors became available, and also cheaper DACs and ADCs, a single-board computer could be used to do what previously required an entire cabinet with a logical one-bit processor and an analog computer.