This project is an abstract logic model of the Intel 8080 microprocessor written in C. To be more precise, this model replicates a clone of the original Intel 8080 called KR580VM80A manufactured in Russia.
According to tests, this models works exactly the same way as the real KR580VM80A including vaguely documented or even undocumented features. The extensive "8080/8085 CPU Exerciser" test by Ian Bartholomew provides strong guarantees of the match.
Use any standard C compiler, for example, GNU C, Visual Studio or TCC. But the Makefile requires GNU Make.
Type make, and it should build and run the test suite. It must print out
the following:
*********************************
File "CPUTEST.COM" loaded, size 19200
DIAGNOSTICS II V1.2 - CPU TEST
COPYRIGHT (C) 1981 - SUPERSOFT ASSOCIATES
ABCDEFGHIJKLMNOPQRSTUVWXYZ
CPU IS 8080/8085
BEGIN TIMING TEST
END TIMING TEST
CPU TESTS OK
Jump to 0000 from 3B25
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File "TEST.COM" loaded, size 1793
MICROCOSM ASSOCIATES 8080/8085 CPU DIAGNOSTIC VERSION 1.0 (C) 1980
CPU IS OPERATIONAL
Jump to 0000 from 014F
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File "8080PRE.COM" loaded, size 1024
8080 Preliminary tests complete
Jump to 0000 from 032F
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File "8080EX1.COM" loaded, size 4608
8080 instruction exerciser (KR580VM80A CPU)
dad <b,d,h,sp>................ OK
aluop nn...................... OK
aluop <b,c,d,e,h,l,m,a>....... OK
<daa,cma,stc,cmc>............. OK
<inr,dcr> a................... OK
<inr,dcr> b................... OK
<inx,dcx> b................... OK
<inr,dcr> c................... OK
<inr,dcr> d................... OK
<inx,dcx> d................... OK
<inr,dcr> e................... OK
<inr,dcr> h................... OK
<inx,dcx> h................... OK
<inr,dcr> l................... OK
<inr,dcr> m................... OK
<inx,dcx> sp.................. OK
lhld nnnn..................... OK
shld nnnn..................... OK
lxi <b,d,h,sp>,nnnn........... OK
ldax <b,d>.................... OK
mvi <b,c,d,e,h,l,m,a>,nn...... OK
mov <bcdehla>,<bcdehla>....... OK
sta nnnn / lda nnnn........... OK
<rlc,rrc,ral,rar>............. OK
stax <b,d>.................... OK
Tests complete
Jump to 0000 from 0137
The test suite includes four tests at the moment:
-
8080/8085 CPU Diagnostic, version 1.0, by Microcosm Associates (file
TEST.COM) -
Diagnostics II, version 1.2, CPU test by Supersoft Associates (file
CPUTEST.COM) -
8080/8085 CPU Exerciser by Ian Bartholomew and Frank Cringles
- The preliminary test (file
8080PRE.COM). - The basic excerciser (file
8080EX1.COM). This file is a copy of the vanilla8080EXER.COMfile having CRCs from the real KR580VM80A contributed by Alexander Timoshenko and Viacheslav Slavinsky.
- The preliminary test (file
All tests pass.
Unfortunately, the current implementation needs the little-endian system to run properly. It uses unions to mix different data types, and such technique is not portable across little- and big-endian systems. Fortunately, most of popular desktop systems running Windows and OSX are based on Intel x86/64 which is little endian. Also, this emulator was tested on the PIC32 platform (little endian as well).
The implemention of the Intel 8080 model is self-contained and independent.
It only requires the i8080_hal.h header providing the hardware abstraction
layer.
The example of use is the test suite (i8080_test.c and i8080_hal.c).
It creates bare miminum hardware plumbing to run tests.
The code can be also built on the WebAssembly platform using emscripten:
make build-wasm
Run WebAssembly test suite in the command line (node executable is required):
make run-node
To run the test suite in the browser, start the local web server:
make web-browser
In the browser, open the URL http://localhost:8000/i8080_test.html or in another terminal run:
make run-web
- Viacheslav Slavinsky, Vector-06C FPGA Replica
- Dmitry Tselikov, Bashrikia-2M and Radio-86RK on Altera DE1
- Ian Bartholomew, 8080/8085 CPU Exerciser
- Frank Cringle, The original exerciser for the Z80
- zx.pk.ru and nedopc.org/forum communities