Three machines in one box.
| Chip | Where | Role |
|---|
| 8563 VDC | U22 | 80-column RGBI video controller with its own video RAM |
| 8564 / 8566 VIC-IIe | U21 (8564 NTSC / 8566 PAL) | 40-column video, C64-compatible, plus C128 clocks and keyboard scan |
| 8721 PLA | U11 | C128 address decode: ROM/RAM banks, chip selects, VIC and color RAM |
| 8722 MMU | U7 | Memory management: ROM/RAM banks, common areas, CPU select |
| 8502 CPU | U6 | CPU (6510 family, native C128 mode) |
| Z80A CPU | U10 | Main CPU (8-bit, 40-DIP) |
| 6581 / 8580 SID | U5 | Sound + paddle A/D |
| 6526 CIA | U1, U4 | Keyboard, joysticks, serial, user port |
| 4164 DRAM 64K×1 | U38-U53 | Main RAM (8 chips = 64 KB) |
| 4416 DRAM 16K×4 | U23, U25 (8563 video RAM) | C16 main RAM (2 chips = 16 KB); C128 VDC video RAM |
| 23128 Mask ROM 16K×8 | U32 (251913-01, 64 mode), U33 (318018), U34 (318019), U35 (318020) on early boards; later boards fit a 23256 at U32 and at U34 | BASIC and KERNAL ROMs (C16, Plus/4, C64C short board, C128) |
| 2364 Mask ROM 8K×8 | U18 (character ROM 390059-01, 2364-318; some national versions fit a 2764 EPROM) | BASIC and KERNAL ROMs (C64); BASIC and KERNAL (VIC-20, PET); character ROM (C128) |
| 6116 2K x 8 static RAM | U19 (2016 in the parts lists) | 2K x 8 static RAM. |
| 8701 / 7701 clock generator | U28 | Dot clock and color clock from one crystal (later C64 boards, C128) |