128MB-SIMM
About the 128MB-SIMM PCB
128MB-SIMM is an open source PCB design by herzmx, published on GitHub under the CC-BY-NC-4.0 license. It is a 4-layer board measuring 108 × 25.3 mm, with 29 components from 12 distinct parts.
Other key parts include the LM1117-3.3, 74LVC4245A, 74LVC245A, S29GL01GS and LVC00A. By type, the board carries 14 capacitors, 9 ICs, 4 resistors and 2 connectors.
From the project
CPS3 NOS is an alternative to the original SIMMs for CPS3; currently, the available options include clone SIMMs with old-stock FLASH memory and Ultra SIMMs by DS.
CPS3 NOS is an alternative to the original SIMMs for CPS3; currently, the available options include clone SIMMs with old-stock FLASH memory and Ultra SIMMs by DS.
The project shares similarities with UltraSIMM but is not based on it. Instead, it is a new implementation built using publicly available pinouts and CPS3 schematics from FPGA projects.
The initial design aimed to use SPANSION NOR FLASH as the main memory, but this proved unfeasible due to speed limitations causing significant instability. As a result, MICRON NOR FLASH was used instead. While this is the same type of memory used…
Main components on the 128MB-SIMM
128MB-SIMM bill of materials (BOM)
29 components, 12 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | LM1117-3.3 | SOT-223-3_TabPin2 | U1 |
| 2 | 74LVC4245A | TSSOP-24_4.4x7.8mm_P0.65mm | U2, U3 |
| 3 | 74LVC245A | TSSOP-20_4.4x6.5mm_P0.65mm | U4, U5, U6 |
| 1 | S29GL01GS | TSOP-I-56_18.4x14mm_P0.5mm | U7 |
| 1 | LVC00A | TSSOP-14_4.4x5mm_P0.65mm | U8 |
| 1 | LVC08A | TSSOP-14_4.4x5mm_P0.65mm | U9 |
| 1 | 5822030-3 128MB | SIMM_EDGE | J1 |
| 1 | CONN_02X03_ODD_EVEN Conn_02x03_Odd_Even | PinSocket_2x03_P1.27mm_Horizontal | J2 |
| 1 | 100UF 100uf | CP_EIA-3528-12_Kemet-T | C1 |
| 2 | 10UF 10uf | CP_EIA-3216-10_Kemet-I | C2, C4 |
| 11 | 100NF 100nf | C_0603_1608Metric | C3, C5, C6, C7, C8, C9, C10, C11 +3 |
| 4 | 10K | R_0603_1608Metric | R1, R2, R3, R4 |
128MB-SIMM design files
The KiCad project lives in the herzmx/cps3-nos repository on GitHub; these links point at the commit this page was built from.
128MB-SIMM: common questions
How big is the 128MB-SIMM PCB?
The 128MB-SIMM measures 108 × 25.3 mm, has 4 copper layers and is 1.2 mm thick.
How many components are on the 128MB-SIMM?
29 components, from 12 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 128MB-SIMM design files?
From the herzmx/cps3-nos repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.
Can I use the 128MB-SIMM design in my own project?
It is published under CC-BY-NC-4.0, which limits how it may be reused; read the license before building on it.
