1551-RAMBOard
About the 1551-RAMBOard PCB
1551-RAMBOard is an open source PCB design by ytmytm, published on GitHub. It is a 2-layer board measuring 58.7 × 40.6 mm, with 9 components from 8 distinct parts.
Other key parts include the 27C512, 74LS139, KM62256CLP, 74LS00 and 27128. By type, the board carries 5 ICs, 2 connectors and 2 resistors.
From the project
RAM/ROM expansion for 1551 to add 8K of RAM / 24K of ROM to cache whole tracks in extra RAM
This project adds 8K of RAM and 8K of extra ROM space to a Commodore 1551 disk drive by replacing the ROM with a small daughterboard. The extra memory is used by a ROM patch to implement a simple track cache: read an entire track once, then serve subsequent sector reads from RAM.
A 27x (relative to 1541) / 7x (relative to 1551) fastloader is provided.
The mod and patched ROM are detected and utilized by Parobek ROM.
Main components on the 1551-RAMBOard
1551-RAMBOard bill of materials (BOM)
9 components, 8 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | 27C512 | DIP-28_W15.24mm_Socket_LongPads | U1 |
| 1 | 74LS139 | DIP-16_W7.62mm_Socket_LongPads | U2 |
| 1 | KM62256CLP | DIP-28_W15.24mm_Socket_LongPads | U3 |
| 1 | 74LS00 | DIP-14_W7.62mm_Socket_LongPads | U4 |
| 1 | 27128 | DIP-28_W15.24mm_Socket_LongPads | U4_SOCKET1 |
| 1 | Conn_01x02_Pin | PinHeader_1x02_P2.54mm_Vertical | J1 |
| 1 | Conn_01x03_Pin | PinHeader_1x03_P2.54mm_Vertical | J2 |
| 2 | 10K | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R13, R15 |
1551-RAMBOard design files
The KiCad project lives in the ytmytm/1551-RAMBOard repository on GitHub; these links point at the commit this page was built from.
1551-RAMBOard: common questions
How big is the 1551-RAMBOard PCB?
The 1551-RAMBOard measures 58.7 × 40.6 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the 1551-RAMBOard?
9 components, from 8 distinct parts. The full bill of materials is listed on this page.
Where can I download the 1551-RAMBOard design files?
From the ytmytm/1551-RAMBOard repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.
Can I use the 1551-RAMBOard design in my own project?
The repository has no license, so all rights stay with ytmytm. Use it as a reference, and ask the author before reusing the design.