Discrete transistor computers

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marcelk
Posts: 490
Joined: 13 May 2018, 08:26

Discrete transistor computers

Post by marcelk » 15 Feb 2020, 16:49

Homebrew CPU wisdom dictates that discrete transistor computers must be much slower than TTL computers. "Due to capacitances and noise levels", as people usually put it. The MT15, Megaprocessor and Monster6502 are then given as examples. After all, each of those max out well below 1 MHz.

However, back in 1964 the CDC 6600 ran its resistor-transistor logic gates (RTL) at 10 MHz. How come?

Here's a really nice blog post about how that works, and why it is so hard to do the same today: https://cpldcpu.wordpress.com/2020/02/1 ... 6600-fast/


CDC6500.jpg
Inside the CDC6500 at LCM+L
CDC6500.jpg (219.48 KiB) Viewed 2848 times

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ECL
Posts: 26
Joined: 01 Feb 2020, 17:56

Q1 Discrete transistor computer

Post by ECL » 16 Feb 2020, 19:25

http://joewing.net/projects/q1/

from the guy who wrote the JWM window-manager

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marcelk
Posts: 490
Joined: 13 May 2018, 08:26

Re: Q1 Discrete transistor computer

Post by marcelk » 17 Feb 2020, 07:11

ECL wrote:
16 Feb 2020, 19:25
from the guy who wrote the JWM window-manager
The site doesn't give an operating speed for the Q1. But it appears to use slow transistors also.

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