GSSquared Test Suites Status¶

In GSSquared development, I frequently utilized what is known as test-driven development. Test programs are written to exercise hardware, record behavior, and then the emulator is written to also match the recorded results.

Summary: At this time there are no known issues with 65C02 or 65816 emulation; N6502 lacks support for the "undocumented opcodes".

IIgs needs support for PAL timing and 14/16MHz mode switching effects; NTSC/PAL colorburst handling needs improvement;

IIgs IWM needs work.

With the exception of the N6502 above, this is cosmetic and none causes software to crash.

Tests¶

Test	Platforms	Pass/Fail	Notes
6502IRQ	IIe	✅	Tests exact 6502 IRQ timing inside instruction execution
Textfunk	IIgs	✅	There is still a minor timing discrepancy that affects the border coloring but not display of the pictures
mb-audit	IIe	✅	Tom Charlesworth amazing Mockingboard Test
Built-in Diag	IIe	✅	Passes
ROM 01 Built-in Diag	IIgs	✅	Passes
ROM 03 Built-in Diag	IIgs	❌	Fails due to missing ADB Sticky Keys
6502_65C02_functional_tests	II+, IIe, IIe Enh	✅	100% pass
snes-tests	IIgs	✅	A pretty good SNES emulation community 65816 test
cycletest	IIe, IIgs	✅	I wrote this test, it passes 100% but it missed a few instructions, needs an update
IWMtest	IIgs	✅❌	Ian Brumby test suite for IWM - we pass about half
Zellyn Audit	✅	IIe MMU / lang card / aux bank tests
Apple II+ Diagnostic Disk	II+	✅	Apple tool for II+ era, disks, language card, RAM test, joystick
Apple IIgs Diagnostic 3.1	IIgs	✅❌	Fails SCC; System Speed/Interrupts;
truegs	IIgs	✅	Tests SHR Linearization and Tech Note #201
Sather 3.10B	II+ IIe IIgs	✅	The first cycle-counting screen demo
Locksmith	IIe	✅	Can bit-copy copy protected WOZ disks; speed test returns correct 300RPM
Crazy Cycles & CCII	IIe IIgs	✅	Correct except colorburst handling
XMAS Demo	IIgs	We don't handle display pixel clock shift between 14MHz/16MHz correctly
Woz Test Disks	IIe, IIgs	✅	All copy-protected woz disk images boot and run correctly
Alien Mind	IIgs	✅	Copy-protected 3.5" disk title, runs correctly

Arekkusu¶

This series of tests deserves its own section because they are so intricate and thorough.

Switches¶

Platforms	Pass/Fail	Notes
II+	✅❌
IIe	✅❌
IIgs	✅❌

Generally speaking, GS2 is:

[ ] Doing it about half right

[ ] not correctly reflecting colorburst hold latency. We are determining colorburst per scanline based on the video mode at start of scanline. real monitors hold colorburst for some period via a PLL even after II stops sending colorburst.

[ ] not switching character widths quite right (e.g. when switching from 40 to 80, latency in the switch interacting with the video shift registers )

CPU¶

Platforms	Pass/Fail	Notes
IIgs	✅	Completely accurate

One of the few Arekkusu tests GS2 gets completely right.

IRQ¶

Platforms	Pass/Fail	Notes
IIgs	✅❌	We partially fail QTR and SEC IRQ tests due to missing support for PAL video mode