The 0.078 set is the "Gold Standard" for the and MAME 2003-Plus cores. Mame2003 (0.78) - which folder do ROMs go? - RetroPie Forum
The CHD format has been revised multiple times. MAME 0.078 requires CHD version 2 (CHDv2). Modern MAME uses CHDv5. You cannot take a modern CHD and run it in MAME 2003. The Reference Set specifically provides the vintage CHDv2 files. MAME 2003 Reference Set - MAME 0.078 ROMs- CHDs...
Whether you are building a Raspberry Pi arcade cabinet or using an older PC, understanding the nuances of the 0.078 set is essential for a smooth experience. Why MAME 0.078 is the Industry Standard MAME 0
The 2003 set was built during an era where efficiency was mandatory. For low-power hardware like the Raspberry Pi 3/4, older Android handhelds, or even the Wii, MAME 0.078 provides the perfect balance between accurate emulation and full-speed performance. 2. The MAME 2003 / Plus Core The Reference Set specifically provides the vintage CHDv2
This set includes those beefy "Compressed Hunks of Data" (CHDs). These are the hard drive and CD-ROM images for 90s classics like Killer Instinct Maximum Force