A complete emulation of the Intel 8080 processor written in C99. Goals:
- accuracy: it passes all test roms at my disposal
- readability
- portability: tested on debian 8 with gcc 5, macOS 10.12+ with clang and emscripten 1.39
You can see it in action in my Space Invaders emulator.
You can run the tests by running make && ./i8080_tests. The emulator passes the following tests:
- TST8080.COM
- CPUTEST.COM
- 8080PRE.COM
- 8080EXM.COM
The test roms (cpu_tests folder) are taken from here and take approximately 30 seconds on my computer (MacBook Pro mid-2014) to run.
The standard output is as follows:
*** TEST: cpu_tests/TST8080.COM
MICROCOSM ASSOCIATES 8080/8085 CPU DIAGNOSTIC
VERSION 1.0 (C) 1980
CPU IS OPERATIONAL
*** 651 instructions executed on 4924 cycles (expected=4924, diff=0)
*** TEST: cpu_tests/CPUTEST.COM
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
*** 33971311 instructions executed on 255653383 cycles (expected=255653383, diff=0)
*** TEST: cpu_tests/8080PRE.COM
8080 Preliminary tests complete
*** 1061 instructions executed on 7817 cycles (expected=7817, diff=0)
*** TEST: cpu_tests/8080EXM.COM
8080 instruction exerciser
dad <b,d,h,sp>................ PASS! crc is:14474ba6
aluop nn...................... PASS! crc is:9e922f9e
aluop <b,c,d,e,h,l,m,a>....... PASS! crc is:cf762c86
<daa,cma,stc,cmc>............. PASS! crc is:bb3f030c
<inr,dcr> a................... PASS! crc is:adb6460e
<inr,dcr> b................... PASS! crc is:83ed1345
<inx,dcx> b................... PASS! crc is:f79287cd
<inr,dcr> c................... PASS! crc is:e5f6721b
<inr,dcr> d................... PASS! crc is:15b5579a
<inx,dcx> d................... PASS! crc is:7f4e2501
<inr,dcr> e................... PASS! crc is:cf2ab396
<inr,dcr> h................... PASS! crc is:12b2952c
<inx,dcx> h................... PASS! crc is:9f2b23c0
<inr,dcr> l................... PASS! crc is:ff57d356
<inr,dcr> m................... PASS! crc is:92e963bd
<inx,dcx> sp.................. PASS! crc is:d5702fab
lhld nnnn..................... PASS! crc is:a9c3d5cb
shld nnnn..................... PASS! crc is:e8864f26
lxi <b,d,h,sp>,nnnn........... PASS! crc is:fcf46e12
ldax <b,d>.................... PASS! crc is:2b821d5f
mvi <b,c,d,e,h,l,m,a>,nn...... PASS! crc is:eaa72044
mov <bcdehla>,<bcdehla>....... PASS! crc is:10b58cee
sta nnnn / lda nnnn........... PASS! crc is:ed57af72
<rlc,rrc,ral,rar>............. PASS! crc is:e0d89235
stax <b,d>.................... PASS! crc is:2b0471e9
Tests complete
*** 2919050698 instructions executed on 23803381171 cycles (expected=23803381171, diff=0)