Omega-Mainboard
About the Omega-Mainboard PCB
Omega-Mainboard is an open source PCB design by merlinkv, published on GitHub under the GPL-3.0 license. It is a 2-layer board measuring 333.4 × 149.9 mm, with 248 components from 105 distinct parts.
Other key parts include the Z84C00, 82C55, V9938/V9958, YM2149 and RP5C01. By type, the board carries 96 capacitors, 49 ICs, 48 resistors, 23 connectors, 8 jumpers and 3 crystals.
From the project
Update of the Omega Home Computer Project
This project is an open source implementation of an MSX2 compatible computer. The project is built using a combination of 1980's era components - Z80 CPU, V9958 VDP, AY-3-8910/YM2149F PSG, 8255 PPI, 7400-series logic, and some newer components, such as 512 KiB SRAM and 512 KiB Flash ROM and a few simple programmable logic devices (ATF16V8B SPLDs).
* 14-04-2024 - Version updated to 1.2 MKV - Schematics, PCB and Gerbers successfully ported to KiCad 8.0.1 - The board has been rerouted. - Some components are now SMD - Interactive BOM
Main components on the Omega-Mainboard
Omega-Mainboard bill of materials (BOM)
248 components, 105 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | Z84C00 | DIP-40_W15.24mm_Socket | U1 |
| 1 | 82C55 | DIP-40_W15.24mm_Socket | U2 |
| 1 | V9938/V9958 | IC_SDIP64_600 | U3 |
| 1 | YM2149 | DIP-40_W15.24mm_Socket | U4 |
| 1 | RP5C01 | DIP-18_W7.62mm_Socket | U5 |
| 1 | SST39SF040 | DIP-32_W15.24mm_Socket | U6 |
| 1 | AS6C4008 | DIP-32_W15.24mm_Socket | U7 |
| 4 | D41464 | DIP-18_W7.62mm_Socket | U8, U9, U10, U11 |
| 3 | ATF16V8B | DIP-20_W7.62mm_Socket | U12, U13, U14 |
| 4 | 74HCT670 | DIP-16_W7.62mm_Socket | U15, U16, U17, U18 |
| 3 | 74F541 | DIP-20_W7.62mm_Socket | U19, U20, U21 |
| 1 | 74HCT540 | DIP-20_W7.62mm_Socket | U22 |
| 2 | 74HCT273 | DIP-20_W7.62mm_Socket | U23, U24 |
| 2 | 74F245 | DIP-20_W7.62mm_Socket | U25, U26 |
| 1 | 74HCT175 | DIP-16_W7.62mm_Socket | U27 |
| 2 | 74HCT157 | DIP-16_W7.62mm_Socket | U28, U29 |
| 2 | 74HCT153 | DIP-16_W7.62mm_Socket | U30, U31 |
| 1 | 74AHCT138 | DIP-16_W7.62mm_Socket | U32 |
| 1 | 74AHCT125 | DIP-14_W7.62mm_Socket | U33 |
| 3 | 74HCT74 | DIP-14_W7.62mm_Socket | U34, U35, U36 |
Show 85 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 3 | 74AHCT32 | DIP-14_W7.62mm_Socket | U37, U38, U39 |
| 2 | 74HCT30 | DIP-14_W7.62mm_Socket | U40, U41 |
| 1 | 74LS07 | DIP-14_W7.62mm_Socket | U42 |
| 1 | 74HCT04 | DIP-14_W7.62mm_Socket | U43 |
| 1 | 74AHCT02 | DIP-14_W7.62mm_Socket | U44 |
| 1 | 74HCT00 | DIP-14_W7.62mm_Socket | U45 |
| 1 | ADM691A | DIP-16_W7.62mm_Socket | U46 |
| 1 | CXA1645 | IC_DIP24_400 | U47 |
| 1 | MCP6281 | DIP-8_W7.62mm_Socket | U48 |
| 1 | LM311 | DIP-8_W7.62mm_Socket | U49 |
| 2 | PN2907A | TO-92L_Inline_Wide | Q1, Q2 |
| 1 | 21.477270MHz | Crystal_HC49-U_Vertical | Y1 |
| 1 | 32768 Hz | Crystal_C38-LF_D3.0mm_L8.0mm_Horizontal_1EP_style2 | Y2 |
| 1 | 4.433618MHz | Crystal_HC49-U_Vertical | Y3 |
| 1 | 5V | BarrelJack_Horizontal | J1 |
| 1 | Composite | Conn_RCA_Right | J2 |
| 1 | Audio | Conn_RCA_Right | J3 |
| 1 | S-VIDEO | Conn_Mini_DIN_4pin | J4 |
| 1 | RGB | DIN8 | J5 |
| 1 | Cassette | DIN8 | J6 |
| 1 | PRINTER | Conn_Micro_Ribbon_14F | J9 |
| 1 | POWER | Molex_KK-254_AE-6410-05A_1x05_P2.54mm_Vertical | J10 |
| 1 | KEYBOARD | IDC-Header_2x08_P2.54mm_Vertical | J11 |
| 1 | RAM_EXT | PinHeader_2x20_P2.54mm_Vertical | J12 |
| 1 | CBUS | PinHeader_1x13_P2.54mm_Vertical | J14 |
| 1 | To_FMPAC | Molex_KK-254_AE-6410-02A_1x02_P2.54mm_Vertical | J15 |
| 1 | FMPAC_PWR | Molex_KK-254_AE-6410-03A_1x03_P2.54mm_Vertical | J16 |
| 1 | VIDEO_CONN | Molex_KK-254_AE-6410-05A_1x05_P2.54mm_Vertical | J17 |
| 1 | AUDIO_CONN | Molex_KK-254_AE-6410-02A_1x02_P2.54mm_Vertical | J18 |
| 1 | EXTR_PWR1 | Molex_KK-254_AE-6410-02A_1x02_P2.54mm_Vertical | J19 |
| 1 | EXTR_PWR2 | Molex_KK-254_AE-6410-02A_1x02_P2.54mm_Vertical | J20 |
| 1 | EXTR_PWR3 | Molex_KK-254_AE-6410-03A_1x03_P2.54mm_Vertical | J21 |
| 1 | SVIDEO_CONN | Molex_KK-254_AE-6410-03A_1x03_P2.54mm_Vertical | J22 |
| 1 | NMI | Molex_KK-254_AE-6410-02A_1x02_P2.54mm_Vertical | J23 |
| 1 | RESET | Molex_KK-254_AE-6410-02A_1x02_P2.54mm_Vertical | J24 |
| 1 | FDD_PWR | PinHeader_1x04_P2.54mm_Horizontal | J25 |
| 1 | PWR_SWITCH | Molex_KK-254_AE-6410-02A_1x02_P2.54mm_Vertical | J26 |
| 1 | CR2032 | Battery_Holder_CR2032_Universal | BT1 |
| 1 | 750mA | Fuse_1206_3216Metric_Pad1.42x1.75mm_HandSolder | F1 |
| 1 | ROM_A18 | Molex_KK-254_AE-6410-02A_1x02_P2.54mm_Vertical | JP1 |
| 1 | KBD_TYPE | PinHeader_1x02_P2.54mm_Vertical | JP2 |
| 2 | V9938/V9958 | PinHeader_1x03_P2.54mm_Vertical | JP3, JP4 |
| 2 | NTSC/PAL | PinHeader_1x03_P2.54mm_Vertical | JP5, JP6 |
| 2 | RAM_SIZE | PinHeader_2x03_P2.54mm_Vertical | JP7, JP8 |
| 4 | 10K | R_Array_SIP10 | RR1, RR2, RR3, RR4 |
| 3 | 4.7K | R_Array_SIP10 | RR5, RR6, RR7 |
| 2 | 4.7K | R_Array_SIP6 | RR8, RR10 |
| 1 | 470 | R_Array_SIP6 | RR9 |
| 1 | Relay_5V | Relay_SPDT | RY1 |
| 2 | MSX_SLOT_HOST | Conn_Edge_50P | SLOT1, SLOT2 |
| 1 | 1N4148 | D_1206_3216Metric_Pad1.42x1.75mm_HandSolder | D1 |
| 1 | 68uH | L_1206_3216Metric_Pad1.42x1.75mm_HandSolder | L1 |
| 2 | 5.6uH | L_1206_3216Metric_Pad1.42x1.75mm_HandSolder | L2, L3 |
| 57 | 100nF | C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C1, C2, C3, C4, C5, C6, C8, C9 +49 |
| 1 | 100uF | C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C7 |
| 8 | 220uF | CP_Radial_D10.0mm_P5.00mm | C59, C60, C61, C62, C63, C64, C66, C67 |
| 1 | 470uF | CP_Radial_D10.0mm_P5.00mm | C65 |
| 12 | 10uF | CP_Radial_D5.0mm_P2.50mm | C68, C69, C70, C71, C72, C73, C74, C75 +4 |
| 1 | 1uF | CP_Radial_D5.0mm_P2.50mm | C78 |
| 2 | 22nF | C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C79, C80 |
| 1 | 1.5nF | C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C81 |
| 3 | 330pF | C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C82, C83, C84 |
| 1 | 47pF | C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C85 |
| 2 | 33pF | C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C86, C87 |
| 3 | 30pF | C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C88, C89, C90 |
| 1 | 27pF | C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C91 |
| 2 | 22pF | C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C92, C93 |
| 1 | 4.7pF | C_1206_3216Metric_Pad1.42x1.75mm_HandSolder | C94 |
| 1 | 1M | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R1 |
| 2 | 470K | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R2, R3 |
| 1 | 220K | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R4 |
| 2 | 100k | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R5, R6 |
| 2 | 47K | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R7, R8 |
| 2 | 20K | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R9, R10 |
| 4 | 10K | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R11, R12, R13, R14 |
| 1 | 5.6K | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R15 |
| 7 | 4.7K | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R16, R17, R18, R19, R20, R21, R22 |
| 2 | 2.7K | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R23, R24 |
| 2 | 2.2K | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R25, R26 |
| 7 | 1K | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R27, R28, R29, R30, R31, R32, R33 |
| 1 | 470 | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R34 |
| 1 | 180 | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R35 |
| 1 | 120 | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R36 |
| 6 | 100 | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R37, R38, R39, R40, R41, R42 |
| 6 | 75 | R_1206_3216Metric_Pad1.42x1.75mm_HandSolder | R43, R44, R45, R46, R47, R48 |
Omega-Mainboard design files
The KiCad project lives in the merlinkv/Omega_MSX2 repository on GitHub; these links point at the commit this page was built from.
Omega-Mainboard: common questions
How big is the Omega-Mainboard PCB?
The Omega-Mainboard measures 333.4 × 149.9 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Omega-Mainboard?
248 components, from 105 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.
Where can I download the Omega-Mainboard design files?
From the merlinkv/Omega_MSX2 repository on GitHub, which has the KiCad layout and the BOM; the links under Design files point to each one.
Can I use the Omega-Mainboard design in my own project?
Yes, under the terms of its GPL-3.0 license, which merlinkv chose for the repository.
