chip8-test-rom

Chip8 / SChip Test ROM

Originally written and published by Sergey Naydenov (Tronix)

Small program for testing (S)CHIP-8 emulators. If all test passed, "OK" is displayed in the upper left corner, otherwise the program prints ERROR followed by the error code.

Error codes:

• ERROR INI - Emulator initialization failed. When program starts, all registers (V0-VF) must be set to 0.
• ERROR BCD - BCD instruction problems.
• ERROR 0 - Problems with Fx65 instruction. Can't load zeroes from memory to registers.
• ERROR 1 - System font 8x5 not found. In memory at offset 000h - zeroes.
• ERROR 2 - Addition without overflow (254+1). VF register need to be set to 0, but after operation it is still 1
• ERROR 3 - After operation 254+1, register v0 needs to be set to 255, but it doesn't.
• ERROR 4 - Addition with overflow (255+1). VF register must be set to 1, but after operation it is still 0
• ERROR 5 - Wrong result after addition operation (255+1). Must be 0.
• ERROR 6 - After subtraction 1-1 register VF must be 1, but it is still 0.
• ERROR 7 - Wrong result after 1-1 operation. Result must be 0.
• ERROR 8 - Subtract 0-1. VF register must be 0, but it is still 1
• ERROR 9 - Wrong result after 0-1 operation. Register v0 must be 255.
• ERROR 10 - TBD
• ERROR 11 - TBD
• ERROR 12 - TBD
• ERROR 13 - TBD
• ERROR 14 - TBD
• ERROR 15 - TBD
• ERROR 16 - TBD
• ERROR 17 - TBD
• ERROR 18 - TBD
• ERROR 19 - TBD
• ERROR 20 - TBD
• ERROR 21 - TBD
• ERROR 22 - TBD
• ERROR 23 - Can not restore HP48 flags (FX75/FX85 instructions).
• ERROR 24 - Check FX1E (I = I + VX) buffer overflow. If buffer overflows, register VF must be set to 1, otherwise 0. As a result, register VF not set to 1. This undocumented feature of the Chip-8 and used by Spacefight 2019! game.

Note

SCTEST.SRC is the original assembly of SCTEST.CH8 written in CHIPPER (see this zip file) dialect.

There is an ongoing effort to port the original into Octo syntax for easy assembly.