Questions tagged [io]
The io tag has no usage guidance.
2
questions
7
votes
2answers
1k views
Did general purpose I/O controller chips come with fewer than 40 pins?
I'm aware that 40-pins was a high-water mark for dual-inline package chips for a significant time; many CPUs of the early 1980s (8086, Z80, 6800, 6502, etc) used 40-pin packages, but no larger.
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15
votes
1answer
807 views
Why did POKEing ROM addresses mask port writes?
After reading mcleod_ideafix's answer about the Inves Spectrum+'s "randomize of death", specifically his article on the subject, one thing struck me as odd. From César Hernández Bañó's research:
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