Gameboy Development Forum

If you haven't heard of 240p Test Suite, it's a tool for testing and calibrating monitors and scalers. But not everybody can run 240p Test Suite.

A. Someone owns a Super NES console, Super Game Boy accessory, and EverDrive GB, but no Super EverDrive or SNES PowerPak.
B. Someone owns a Nintendo GameCube console, Game Boy Player accessory, and EverDrive GB, but no GameCube homebrew device.
C. Someone wants to see exactly how much a Game Boy (DMG) or Game Boy Pocket suffers from motion blur and STN smear artifacts, or gloat over the GBC's utter lack thereof.

Hence the 144p Test Suite. It's just a start, but I've already got most of the easy ones (Grid, Linearity, Gray ramp, Solid screen, Sharpness, Grid scroll, Full screen stripes, About, and Credits) going, enough to give a sense of where the project is headed. And I plan to introduce a couple GB-exclusive tests for good measure.

Download: 144p Test Suite 0.01 ROM and source

I'd be interested to see the "special version of the suite" that you make using the transfer and jump mechanism that Space Invaders uses. In particular, I'd like to see how something like that could be squeezed into 32K to fit on an MBC-less cartridge, or whether it'd need something bigger and MBC-ful like an EverDrive. Until then, I'm focusing on finishing the minimum viable product.

I came up with a GB/SNES counterpart to PB8, a CHR data codec used in some of my NES games. (PB8 is LZSS with a fixed distance and length of 1, or equivalently RLE with unary-coded run lengths.) To make RLE effective on Game Boy, TurboGrafx-16, or Super NES, you need to change the fixed distance to 2. I was inspired by the RLE tile codecs used in Master System games, which store the data bitplane-major before compression (like NES tiles) rather than row-major (like Master System and Game Boy tiles) and then reinterleave the data when copying it to VRAM.

I also dug up the text coder that I had for made for another NES project. Byte pair encoding (BPE), also called digram coding or (in the ROM hacking community) dual tile encoding (DTE), is a way of compressing text by mapping otherwise unused high-numbered code units to pairs of characters. For example, code units $20-$87 might be your ASCII code plus a few accented glyphs, and $88-$FF would represent pairs of characters. Recursive BPE, or digram tree encoding (DTE), also allows one or both of the pairs to refer to another (lower-numbered) pair.

0.02 (2018-04-14)
* Solid screen: Mention dead pixel test (requested by calima)
* Compress most tile graphics with PB16, saving about 1.25K
* Compress help text with DTE, saving about 3.5K
* Add tests: Shadow sprite, Hill zone scroll, Vertical scroll, and Stopwatch

Download: 144p Test Suite 0.02 ROM and source
It's only missing six tests.


darryl.revok's portrait of Gus, 128 tiles


Smaller version of mikejmoffitt's Green Hill Zone-alike, 109 tiles

It has come to my attention that someone does want to make a GBC port. To prepare for this, I have made some behind-the-scenes technical changes to 144p Test Suite.

0.04 (2018-04-29)

* No more tarbombing: Create zipfile with all files in an internal folder (requested by calima)
* Skip logo fadeout and SGB detection on Game Boy Color/Advance
* Overscan: Start border thickness at 2 instead of temporary values left in from testing
* Overscan: Draw bottom border with WX instead of LCDC (requested by ISSOtm)
* Stopwatch: Hide face with window instead of LCDC (requested by ISSOtm)
* Hide incomplete first frame with BGP and OBP0 instead of LCDC (requested by ISSOtm)
* Vertical scroll: Fix a buffer overflow causing the test to start paused
* Use de facto standard hardware.inc, with 'r' in front of all port names (requested by ISSOtm)
* Grid test pattern no longer uses Sharpness help screen

Download 144p Test Suite 0.04 ROM and source

I have begun work on adding Game Boy Color enhancements to the following activities:

* Activities using help engine (menu, About, Credits, Sound test)
* Vertical scroll
* Lame boy demo

I have determined that the following could benefit from enhancement (issue #2):

* Gray ramp
* Motion blur
* Solid screen
* Shadow sprite
* Hill zone scroll

I have further determined that the following tests, which were left out due to lack of color, should be included for feature parity with ports on other consoles (issue 1):

* PLUGE
* Gradient color bars
* SMPTE color bars
* Color bars on gray
* Color bleed

But I doubt that I will be able to fit everything in 32K. I started with 26K used and 6K free. After adding the GBC enhancements that I have added so far, I am up to 27.4K used and 4.6K free. Some of this is because some parts need GBC-specific graphics to distinguish, for example, white-as-backdrop from white-as-skin-color from white-as-shirt when two of them occur in the same tile. Once I near the 32K limit of easily obtained flash carts that are less expensive than SD adapters, could anyone here assist in code review to find things I could pack smaller?

It took heroic compression, but I was able to add the color balance tests with 127 bytes to spare.

0.06 (2018-06-03)

* Add GBC-exclusive tests (PLUGE, Gradient color bars, SMPTE bars, Color bars on gray, Color bleed)
* LR35902 assembly source files use .z80 extension for more convenient syntax highlighting
* Backlight zone background is black, not green
* Motion blur, Overscan, and Lame boy demo share 0-9 tiles
* Better compression for tile maps using many tiles only once
* Lame boy demo no longer shows RNG test
* Eliminate some unnecessary ROM byte alignment

Download 144p Test Suite 0.06 (ROM and source)

240p Test Suite (NES, GB, GBA) v0.17

A minor update, largely to track updates to the Genesis version. Also includes continued size optimizations in the Game Boy version.

Highlights:

* Sharpness: A to show brick wall pattern (Genesis 1.16 parity)
* Stopwatch: Add third ruler setting to show in even frames (Genesis 1.16 parity)
* Audio sync: Move ceiling up (Genesis 1.16 parity)
* Begin to unify help conversion tooling
* Unify version numbers
* Help (GB): Compress document titles with DTE
* Gray ramp (GB): Use Color tests map loader for GBC version
* Solid screen (GB, GBA): Explain what a bad high voltage regulator does to SGB and GB Player border (requested by ISSOtm)
* Stopwatch (GB, GBA): Draw even frame numbers in blue and odd in red (Genesis 1.16 parity)
* Manual lag (GB): Fix all-black result screen if final press was 0 lag (reported by Great Hierophant, echoing Quietust's NES report)
* GB: ISSOtm golfed SGB detection by 3 bytes; numerous other size optimizations and tile sheet unifications

Download: GitHub release | ROM and source (zip)

240p Test Suite (NES, GB, and GBA) v0.19 is out

It took another heroic compression effort, but I freed enough space to add Super Game Boy support to all tests that would benefit from it.

Highlights on all platforms:

* Stopwatch: Bolder digits
* Help: Standardize phrasing: "stuck pixels", "hide or show", "start or stop"
* Help: List patrons as of release time

Highlights on specific platforms:

* GB: Super Game Boy colorization and border
* Backlight zone (NES, GB): Increase starting size to 2 pixels
* Color bleed (GBA): Fix frame # covering everything
* PLUGE Contrast and Vertical scroll (GBA): Center pattern horizontally
* README (GB, GBA): Explain rationale behind "144p" and "160p" titles

Behind the scenes:

* Help (NES, GB): Integrate Johnathan Roatch's faster DTE compressor written in C
* Linearity (GB): Compress with reflection
* GB: Improve incruniq tilemap compression
* GB: Compress font and large graphics with nibble-wise Huffman coding
* GB: Move variables to HRAM; other code size optimizations
* GBA: Use a more common makefile
* GBA: Specify each PNG's conversion settings in a grit file

Download: GitHub release | ROM and source zipfile (553 kB)

144p Test Suite v0.21

Highlights (GB):

* Add Convergence pattern
* Overscan: Change WX in hblank to hide a 1-line-tall glitch (reported by LIJI32)
* Stopwatch: Make hours digit work
* Lame boy: Glove contrast; vest and sleeve trail; squash bottom when on ground; involve the abdominal and back muscles
* Help: Make some descriptions more concise (with Artemio's help)
* SGB border: Simplify title to reuse more tiles and more closely match the recent Genesis version

Behind the scenes (GB):

* Disable -static when building DTE encoder on macOS (#24)
* Vertical scroll (GB): Compress tilemap with PB16
* Help: Move non-ASCII symbols to $18-$1F to free DTE codes; coalesce repeated lines of text; compress each line of text twice and keep the smaller; assume no document has more than 9 pages
* GB: Share code for "Select: Invert grays" and for scroll tests' speed control
* SGB packet sending: Use ring counter
* GB: Switch to smaller ADC/DAA binary to decimal converter
* GB: Numerous micro-optimizations
* GB unused.py: Recognize more optimization opportunities
* GB: Allow use of out-of-PATH copy of RGBDS

Download ROM and source (599 kB) or from the GitHub release

v0.23

It's been a long time coming.

Highlights:

* Credits: Display version from Git commit tag and ID
* Credits: Pino has moved to the Fediverse
* Add SGB sound test
* Add health warning to Motion blur and Chroma crosstalk
* Motion blur: increase duration cap to 60 frames (requested by zeta0134)
* Shadow sprite: replace GB Gus and GBC Gus with Donna
* Shadow sprite: move Green Hill Zone and Donna tiles to $8800
* Rename Manual lag test to Timing and reflex test to reflect how it is used
* Backlight zones: add speed control for measuring afterglow time
* Sound test: add surround option
* MDFourier: play sync pattern when menu opens
* Delay SGB detection by 8 frames for increased compatibility

Download ROM and source zipfile (711 KiB) or from the GitHub release