RC6502 RAM
About the RC6502 RAM PCB
RC6502 RAM is an open source PCB design by tebl, published on GitHub under the GPL-3.0 license. It is a 2-layer board measuring 99.1 × 54.6 mm, with 23 components from 18 distinct parts.
Other key parts include the HM62256BLP-7, 74LS138, 74LS08 and 74LS00. By type, the board carries 12 jumpers, 5 ICs, 5 capacitors and 1 connector.
It belongs with the retro computing designs in this gallery.
From the project
An expandable SBC-version of the Apple 1 computer, easy to get started with and lot of cool stuff that can be added to it!
The original Apple 1 computer only came with 8KB of RAM (Random Access Memory), this was divided into two separate 4KB blocks and should match the following layout (picture from Tom Owads Apple 1 Replica book):
The RC6502 computer makes the same changes to the hardware dealing with RAM as was details in the previously mentioned book, the updated memory map should now match the one included below (note that any optional modules are not included here). The blue areas designating RAM have shifted positions, mostly we've moved the area usually used for Integer Basic into ROM (see the ROM-module…
Main components on the RC6502 RAM
RC6502 RAM bill of materials (BOM)
23 components, 18 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | HM62256BLP-7 | DIP-28_W15.24mm_Socket | U1 |
| 1 | 74LS138 | DIP-16_W7.62mm_Socket | U2 |
| 2 | 74LS08 | DIP-14_W7.62mm_Socket | U3, U4 |
| 1 | 74LS00 | DIP-14_W7.62mm_Socket | U5 |
| 1 | RC6502_Backplane | Pin_Header_Angled_1x39_Pitch2.54mm | J3 |
| 1 | A13_EN | Pin_Header_Straight_1x02_Pitch2.54mm | JP1 |
| 1 | A14_EN | Pin_Header_Straight_1x02_Pitch2.54mm | JP2 |
| 1 | CS0_EN | Pin_Header_Straight_1x03_Pitch2.54mm | JP3 |
| 1 | CS1_EN | Pin_Header_Straight_1x03_Pitch2.54mm | JP4 |
| 1 | CS2_EN | Pin_Header_Straight_1x03_Pitch2.54mm | JP5 |
| 1 | CS3_EN | Pin_Header_Straight_1x03_Pitch2.54mm | JP6 |
| 1 | CS4_EN | Pin_Header_Straight_1x03_Pitch2.54mm | JP7 |
| 1 | CS5_EN | Pin_Header_Straight_1x03_Pitch2.54mm | JP8 |
| 1 | LO/HI | Pin_Header_Straight_1x03_Pitch2.54mm | JP9 |
| 1 | MEM_WE | Pin_Header_Straight_1x03_Pitch2.54mm | JP11 |
| 1 | CS6_EN | Pin_Header_Straight_1x03_Pitch2.54mm | JP12 |
| 1 | CS7_EN | Pin_Header_Straight_1x03_Pitch2.54mm | JP13 |
| 5 | 100nF | C_Disc_D4.7mm_W2.5mm_P5.00mm | C1, C2, C3, C4, C5 |
RC6502 RAM design files
The KiCad project lives in the tebl/RC6502-Apple-1-Replica repository on GitHub; these links point at the commit this page was built from.
RC6502 RAM: common questions
How big is the RC6502 RAM PCB?
The RC6502 RAM measures 99.1 × 54.6 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the RC6502 RAM?
23 components, from 18 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 RC6502 RAM design files?
From the tebl/RC6502-Apple-1-Replica repository on GitHub, which has the KiCad layout and the BOM; the links under Design files point to each one.
Can I use the RC6502 RAM design in my own project?
Yes, under the terms of its GPL-3.0 license, which tebl chose for the repository.
More boards in RC6502-Apple-1-Replica
RC6502 General Video Adapter
99.1 × 99.7 mm80 parts2LGPL-3.0192
AVR/ArduinoRC6502 Apple 1 SBC
99.1 × 99.7 mm48 parts2LGPL-3.0192
RC6502 TIA NTSC
99.1 × 69.2 mm45 parts2LGPL-3.0192
AVR/ArduinoRC6502 Terminal
99.1 × 81.9 mm45 parts2LGPL-3.0192
RC6502 Joystick
99.1 × 61.6 mm44 parts2LGPL-3.0192
RC6502 Prototyping
99.1 × 99.7 mm43 parts2LGPL-3.0192
RC6502 VDU
99.1 × 99.7 mm37 parts2LGPL-3.0192
RC6502 PSG
99.1 × 54.6 mm28 parts2LGPL-3.0192
RC6502 RIOT
99.1 × 69.2 mm26 parts2LGPL-3.0192
AVR/ArduinoRC6502 Serial IO
99.1 × 66 mm21 parts2LGPL-3.0192
RC6502 ROM
99.1 × 54.6 mm14 parts2LGPL-3.0192
Similar boards
OpenTendo
Redherring32
196.3 × 118.7 mm93 parts2LTAPR-OHL-1.0850
MCL86jr
MicroCoreLabs
56.1 × 57.1 mm66 parts4LNo license532
24pin flex interposer
Wren6991
29 × 32 mm3 parts2LNo license508
Sram dev board
50 × 50 mm12 parts2LNo license508
TRS-80 Color Computer 3
baldengineer
280 × 155.3 mm204 parts2LCC-BY-4.0442
Commodore Plus 4
284.7 × 158.9 mm212 parts2LCC-BY-4.0442