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Questions tagged [intel-8080]

The Intel 8080 processor is an 8-bit microprocessor, a predecessor of the famous 8086 series. It shares its instruction set with its successor, the 8085.

The Intel 8080 is an 8-bit microprocessor from the mid-1970s. It was a predecessor of the and of the very popular and series. The 8080 and 8085 are binary compatible (except for a few 8085 additions), but the 8086 (and 8088) uses a wholly different instruction set.

Use this tag for questions about 8080 instructions and programming. For questions regarding instructions on later processor models, use the and tags respectively. For general questions about assembly, use the tag.

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Altair 8800 data and instructions

Recently I have been playing around a little with a Altair 8800 emulator to understand the basics of computing, and I was wondering how does the processor "know" if a byte is an instruction or data?
pedro santos
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Read register pair by bits - assembly i8080

I have a hexadecimal value stored in register pair B. And I want to read it by chars. For example in B is 322 (hexadecimal) I want to have in accumulator 3 then 2 and then 2 (in ASCII). Is it somehow possible? Or is it possible to store this…
miskohut
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Modeling microcomputer registers in memory?

As a little side project I've been creating an older microcomputer CPU emulator, mostly based off the 8080's architecture. Its 8-bit general purpose registers can (according to wikipedia) be used "as three 16-bit register pairs," as well as the…
Lexusjjss
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Can anyone solve this 8080 assembly code 'puzzle'?

A friend of mine was given 8080 assembly code as part of a puzzle he's trying to solve. This is the code: 3E 02 4F C6 04 47 11 41 01 21 69 00 19 76 He needs the values of B, DE, C and HL Can anyone solve this or point me in the right direction on…
user259600
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Printing shapes with assembly for Intel 8080

So as an excercise from my textbook, I'm trying to code a program in assembly for Intel 8080 which will be printing a scalable image of three triangles facing down in the upper row and two facing up in the bottom row. Something like that, to be…
Straightfw
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Where is the result of addition? Intel 8080

I can't understand the behavior of processing code for Intel 8080. For example I want to add two hex numbers: 3H and 4H so I wrote: MVI A, 3H MVI B, 4H ADD B HLT But where can I find the result after processing? Should I copy result from A to some…
krzyhub
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Intel 8080 How to convert decimal number to binary and print it

i am doing some program in Intel 8080 and in the end i have a number in register E. I need this number convert to binary and print it to terminal. For now i am printing it like decimal: mov a,e adi '0' call putchar call newline hlt Can somebody…
Bujak
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Clock cycles in a single 8080 instruction

From the book Code, it says that: The 8080 instruction requires anywhere from 4 to 18 clock cycles". Why would there be such a fluctuation between the number of clock cycles to execute an instruction. What would be an example of an instruction…
David542
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8080 Assembly Clarification

I am making a disassembler for 8080 assembly. Correct me if I'm wrong: All I have to do is read the binary byte by byte, translating each byte into a command. Or are there conditions which would increase the length of the command (in the binary).
picklesrevil
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