MacintoshPortable8MB RAM v3
About the MacintoshPortable8MB RAM v3 PCB
MacintoshPortable8MB RAM v3 is an open source PCB design by 2tf2294x4g-maker, published on GitHub under the CERN-OHL-S-2.0 license. It is a 4-layer board measuring 123 × 81 mm, with 63 components from 14 distinct parts.
Other key parts include the AS6C8008-55ZIN, ATF1502ASL-25AU44 and SN74HC245DW. By type, the board carries 24 resistors, 19 capacitors, 11 ICs, 4 diodes, 3 connectors and 1 jumper.
From the project
Mac Portable Expansion Card with support for 2, 4, 6, or 8 MB and jumper for backlit or non backlit
Expands a Macintosh Portable to 9 MB total (1 MB onboard + 8 MB this card) — the maximum the Portable's address space supports.
All-5V design using 1M×8 SRAM chips and an ATF1502ASL CPLD. Works with both the M5120 (non-backlit) and M5126 (backlit) Portable via the MODEL jumper. Banks are added sequentially — no jumpers needed as you populate.
All 8 SRAMs populated — 9,216K total memory under System 7.5.5.
Main components on the MacintoshPortable8MB RAM v3
MacintoshPortable8MB RAM v3 bill of materials (BOM)
63 components, 14 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 8 | AS6C8008-55ZIN Alliance Memory | TSOP-II-44_10.16x18.41mm_P0.8mm | U1, U2, U3, U4, U5, U6, U7, U8 |
| 1 | ATF1502ASL-25AU44 ATF1502ASL Microchip | TQFP-44_10x10mm_P0.8mm | U9 |
| 2 | SN74HC245DW 74HC245 TI/Nexperia | SOIC-20W_7.5x12.8mm_P1.27mm | U10, U11 |
| 1 | BCS-125-F-D-HE RAM Connector Samtec | Samtec_BCS-125-F-D-HE | J1 |
| 1 | JTAG_Header_2.54mm_1x06 Generic | PinHeader_1x06_P2.54mm_Vertical | J2 |
| 1 | PDS Header 1x2 Generic | PinHeader_1x02_P2.54mm_Vertical | J3 |
| 1 | MODEL: open=M5120(9MB) closed=M5126(7MB) Generic | PinHeader_1x02_P2.54mm_Vertical | JP1 |
| 1 | GND | TestPoint_GND | TP1 |
| 4 | GREEN Generic | LED_0603_1608Metric | D1, D2, D3, D4 |
| 14 | 100NF 100nF Generic | C_0805_2012Metric | C1, C2, C3, C4, C5, C6, C7, C8 +6 |
| 5 | 10UF 10µF Generic | C_0805_2012Metric | C15, C16, C17, C18, C19 |
| 4 | 330 Generic | R_0402_1005Metric | R1, R2, R3, R4 |
| 16 | 10K Generic | R_0402_1005Metric | R5, R6, R7, R8, R9, R10, R11, R12 +8 |
| 4 | 10K Generic | R_0805_2012Metric | R21, R22, R23, R24 |
MacintoshPortable8MB RAM v3 design files
The KiCad project lives in the 2tf2294x4g-maker/MacintoshPortable8MB_RAM_v3 repository on GitHub; these links point at the commit this page was built from.
MacintoshPortable8MB RAM v3: common questions
How big is the MacintoshPortable8MB RAM v3 PCB?
The MacintoshPortable8MB RAM v3 measures 123 × 81 mm, has 4 copper layers and is 1.625 mm thick.
How many components are on the MacintoshPortable8MB RAM v3?
63 components, from 14 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 MacintoshPortable8MB RAM v3 design files?
From the 2tf2294x4g-maker/MacintoshPortable8MB_RAM_v3 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 MacintoshPortable8MB RAM v3 design in my own project?
Yes, under the terms of its CERN-OHL-S-2.0 license, which 2tf2294x4g-maker chose for the repository.