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9 votes

What do the pins D0-D7 on the Intel 8080 exactly signify?

Basics The data bus carries time multiplexed information: At the end of the first clock cycle (*1) of each machine cycle (*2) it always carries the status signals as described on Page 2-6. During the ...
Raffzahn's user avatar
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7 votes

Does the Intel 8080 ANI instruction clear or update the half-carry?

For what it's worth, the MCS-80/85 Family User's Manual (October 1979) has yet another listing of instructions, and in this one it's made very clear that both ANA and ANI behave the same on the 8080: ...
cjs's user avatar
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6 votes

Will disassembling an 8080 program as Z80 code work?

Yes, It's Fine Disassembling an 8080 program using a Z80 disassembler will work just fine, and reassembling it with a Z80 assembler (assuming it uses the same syntax as the disassembler) will ...
cjs's user avatar
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4 votes

Were there any 8080 computers that used a bitmapped display?

You don't mention that you're restricting bitmap displays to a particular minimum resolution, so I will provide this (very) low-resolution example, which may be the earliest microcomputer bitmap ...
cjs's user avatar
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3 votes

Auxiliary Carry and the Intel 8080's logical instructions

This was documented by Intel in 1975, though apparently not in the manual you're looking at (Intel 8080 Assembly Language Programming Manual Rev. B, 1975). Section 4 of the Intel 8080 Microcomputer ...
cjs's user avatar
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3 votes

Long Term Prevalence of 8080 Code Over Z80 Code in Software Packages

I think you can look at this in two ways: What amount of code was actually written in Z80 assembly using Z80 mnemonics, and what amount of code used 8080 mnemonics (otherwise, using the same 8080 ...
tofro's user avatar
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2 votes

Manual for DIAGNOSTICS II V1.2 – CPU TEST SUPERSOFT ASSOCIATES

I have yet to see a manual for this tool, but I have placed here some documentation and a partially annotated disassembly. You don't say what your failure was, but it likely was an opcode test failure....
cjs's user avatar
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2 votes

Is there any known magic number signature for CP/M-80 program files?

Write two small interpreters that understand a subset of 8080 and 8086 opcodes, and use each to trace the first few dozen bytes of proposed execution of the program. Note that you don't need to have ...
cjs's user avatar
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1 vote

Test emulated 8080 CPU without an OS?

In case it's useful to anyone to see some more exact details of how to do the limited CP/M emulation suggested in other answers, the following is some Python code to do this from my testmc simulation ...
cjs's user avatar
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