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2 votes

What is the history and development of memory caching?

Cache in minicomputers. I received a DEC PDP-11/45 in Summer of 1972. The 45 had core memory slots in the backlane as well as, I believe, 4 slots for fast and expensive (semiconductor) memory runing ...
Harvey's user avatar
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4 votes

TMS9918 - why have separate data-in and data-out?

TL;DR: It's two chips in one A memory manager/addressing unit and a streaming display engine (*1), each with their own dedicated data port. Splitting the structure into two unidirectional interfaces ...
Raffzahn's user avatar
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6 votes

TMS9918 - why have separate data-in and data-out?

Let's see the datasheet for 9918 first and see how the VDP to VRAM write sequence works. Before the write cycle, the VRAM chips were all held in the READ mode (R/~W signal is held high by VDP). This ...
user3528438's user avatar
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5 votes

TMS9918 - why have separate data-in and data-out?

The TMS9918 has eight pins that combine "address out" and "data out" functions, while using another eight pins for "data in". Because typical 16Kx1 DRAM chips don't have ...
supercat's user avatar
  • 33.9k
-1 votes

Did any computer use a 7-bit byte?

Some famous Microchip PIC processors, such as the Microchip PIC 16F84 and the Microchip PIC 16F877A, have a "14-bit processor core". They execute all instructions out of a 14-bit-wide memory....
David Cary's user avatar
1 vote

How was early randomness generated?

A very primitive "random" generator is used in the 1984 Karate Champ game. It doesn't even try to be random, it's just using a timer tick value and takes the modulus using the max value. It ...
Jean-François Fabre's user avatar

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