2 layers68.6 × 45.1 mm
2 layers57.2 × 19.1 mm
TANDY 600 RAM DUAL
bkw777/TANDY_600_RAM396K SRAM for TANDY Model 600
- Size
- 57.2 × 19.1 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 8
- Nets
- 69
- Pads
- 163
- Tracks, vias
- 232, 46
- Pours
- 156
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 12 Aug 2021
- Updated
- 29 Oct 2025
Overview
TANDY 600 RAM DUAL is an open-source printed circuit board by bkw777, from the bkw777/TANDY_600_RAM repository on GitHub. It is a 2-layer board of 57.2 × 19.1 mm with 8 parts on 69 nets, routed with 232 tracks and 46 vias.
It is built around the SN74AHC1G02DCKR-TP, AS6C4008-55STIN and SN74HC148DR(LX), with the CL21B105KAFNNNE, PRPC022DAAN-RC and RMCF0805FT200K among its other parts. Its parts include 3 ICs, 2 capacitors, 2 connectors and 1 resistor. It belongs with the radio and wireless and retro computing and games boards of this library.
Main components
6
SN74AHC1G02DCKR-TP
SOT-353-40℃~+125℃ 1.5V~3.85V 1.9V~4.5V 100mV~360mV 1uA 2 2 25mA 25mA 2V~5.5V 500mV~1.65V 7.9ns@3.3V,15pF 74AHC Series Local shutdown mode NOR Gate SOT-353 Logic Gates ROHSTECH PUBLICLogic Gates
AS6C4008-55STIN
STSOP-32-11.8mm-40℃~+85℃ 2.7V~5.5V 30mA 4Mbit 4uA 55ns STSOP-32-11.8mm SRAM ROHSAlliance MemorySRAM
SN74HC148DR(LX)
SOP-16-40℃~+125℃ 14ns@6.0V,50pF 2V~6V 3/8 4uA 74HC Decoder Single Supply SOP-16 Signal Switches, Multiplexers, Decoders ROHSlingxingicSignal Switches, Multiplexers, Decoders
CL21B105KAFNNNE
08051uF 25V X7R ±10% 0805 Multilayer Ceramic Capacitors MLCC - SMD/SMT ROHSSamsung Electro-MechanicsMultilayer Ceramic Capacitors MLCC - SMD/SMT
PRPC022DAAN-RC
插件,P=2.54mmPin HeadersSullins Connector Solutions
RMCF0805FT200K
0805-55℃~+155℃ 125mW 150V 200kΩ Thick Film Resistor ±1% ±100ppm/℃ 0805 Chip Resistor - Surface Mount ROHSStackpole Electronics (SEI)Chip Resistor - Surface Mount
README
README.mdSRAM modules for TANDY 600
There are several versions to choose from. They all work the same. Just pick whichever you like based on size, cost of parts, ease of soldering, ease of installing, etc.
Surface-Mount single-bank 96K easy to solder, polarity keyed, more expensive
Through-Hole single-bank 96K same as above, plus socketable/removable chips
Tiny single-bank 96K more difficult to solder, miniaturized mostly just as a stunt
Tiny dual-bank 192K most practical way to get all 192K if you can manage the soldering
Standard Version
PCB for STANDARD version from PCBWAY
BOM for STANDARD version from DigiKey
Through-Hole Version
Same schematic as the standard version, just with all through-hole components.
The ICs may be socketed or not as you wish. When installed in the 600 there is room for both IC's on both boards to be socketed, and the BOM includes sockets.
PCB for THROUGH-HOLE version from PCBWAY
BOM for THROUGH-HOLE version from DigiKey
Tiny Version
PCB for TINY version from PCBWAY
BOM for TINY version from DigiKey
DUAL VERSION
Single board that plugs into both CN1 and CN2 and supplies all 192K at once.
PCB for DUAL version from PCBWAY
BOM for DUAL version from DigiKey
History / Credits
In 2017 I asked on the Tandy Color Computer Facebook group if anyone could clone a 96K ram board for Model 600, and Jayeson Lee-Steere produced Model600Sram_v1.1 and placed it in the public domain.
This version is different now but started from that.
Parts
8More from bkw777/TANDY_600_RAM
6- 2 layers68.6 × 45.1 mm
- 2 layers68.6 × 45.1 mm
- 2 layers68.6 × 16.5 mm
- 2 layers68.6 × 16.5 mm
- 2 layers68.6 × 16.5 mm
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Questions
How big is the TANDY 600 RAM DUAL PCB?
It measures 57.2 × 19.1 mm and has 2 copper layers, 1.6 mm thick.
What parts does the TANDY 600 RAM DUAL use?
8 parts, built around the SN74AHC1G02DCKR-TP, AS6C4008-55STIN, SN74HC148DR(LX) and CL21B105KAFNNNE. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the TANDY 600 RAM DUAL KiCad files?
From the bkw777/TANDY_600_RAM repository on GitHub, at the commit this page was made from: the board is PCB/TANDY_600_RAM_DUAL.kicad_pcb and its schematic ALT/TANDY_600_RAM_74148.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the TANDY 600 RAM DUAL design in my own project?
Its repository states no licence, so its author keeps all rights: ask bkw777 before reusing the design.