Memory-Access-Register

DutchMaker·TTL-computer·Circuits/KiCad/Memory-Access-Register/Memory-Access-Register.kicad_pcb

Memory-Access-Register PCB layout, top view — open source board by DutchMaker

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About the Memory-Access-Register PCB

Memory-Access-Register is an open source PCB design by DutchMaker, published on GitHub. It is a 2-layer board measuring 144.8 × 114.3 mm, with 39 components from 12 distinct parts.

Other key parts include the 74x08, 74x245, 74x377 and 74x157. By type, the board carries 17 switches, 10 ICs, 5 resistors, 4 connectors and 1 diode.

From the project

Building a computer from scratch using 74xx logic chips

- Add ./Libraries/74xx-Computer-Symbols.lib as global Symbol library to KiCad (Eeschema) - Add ./Libraries as global Footprint library to KiCad (Pcbnew) - PCBs are initially autorouted using ./Libraries/freeRouting.jar and traces are enhanced manually

There are a number of deviations and errors that were found in schematic/PCB designs after PCB production. They are listed here if they were not fixed in the schematic/PCB design files.

Main components on the Memory-Access-Register

74x08 74x245 74x377 74x157

Memory-Access-Register bill of materials (BOM)

39 components, 12 distinct parts.

Qty	Part	Footprint	Refs
1	74x08	DIP-14_W7.62mm	U1
3	74x245	DIP-20_W7.62mm	U2, U3, U4
2	74x377	DIP-20_W7.62mm	U5, U6
4	74x157	DIP-16_W7.62mm	U7, U8, U9, U10
4	Conn_01x16_Male	PinHeader_1x16_P2.54mm_Vertical	J1, J2, J3, J4
2	HDSP-4830_2	HDSP-4830	BAR1, BAR2
16	SW_DPDT_x2	FlipSwitch	SW1, SW2, SW3, SW4, SW5, SW6, SW7, SW8 +8
1	SW_DPDT_x2	Switch	SW17
1	LED	LED_D5.0mm	D1
1	470	R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal	R1
2	10K	R_Array_SIP9	RN1, RN2
2	470	R_Array_SIP9	RN3, RN4

Memory-Access-Register design files

The KiCad project lives in the DutchMaker/TTL-computer repository on GitHub; these links point at the commit this page was built from.

LayoutCircuits/KiCad/Memory-Access-Register/Memory-Access-Register.kicad_pcb

Memory-Access-Register: common questions

How big is the Memory-Access-Register PCB?

The Memory-Access-Register measures 144.8 × 114.3 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Memory-Access-Register?

39 components, from 12 distinct parts. The full bill of materials is listed on this page.

Where can I download the Memory-Access-Register design files?

From the DutchMaker/TTL-computer repository on GitHub, which has the KiCad layout; the links under Design files point to each one.

Can I use the Memory-Access-Register design in my own project?

The repository has no license, so all rights stay with DutchMaker. Use it as a reference, and ask the author before reusing the design.

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