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2 layers99.1 × 99.1 mmCpu rom, the printed circuit board in 3D

MC14500 1bit CPU

Size
99.1 × 99.1 mm
Copper layers
2
Thickness
1.6 mm
Parts
58
Nets
186
Pads
532
Tracks, vias
926, 143
Pours
688
Routed
Yes
KiCad
KiCad 7 (file 20221018)
Created
28 Jan 2024
Updated
30 Aug 2024

Overview

Cpu rom is an open-source printed circuit board by jk1mly, from the jk1mly/cpu-1bit repository on GitHub, published under the BSD-2-Clause licence. It is a 2-layer board of 99.1 × 99.1 mm with 58 parts on 186 nets, routed with 926 tracks and 143 vias.

Its parts include 18 connectors, 17 diodes, 6 resistors, 4 capacitors and 4 ICs.

README

README.md

cpu-1bit

MC14500 1bit CPU

MC14500Bを使って実験を行うための基板と、プログラムをEPROMの代わりにPICに入れるソフト MC14500Bのソフトはprogcd.hに記述 ニーモニックどはopcode.hに定義 main.cはアドレスに従ってデータを出すのみ PICでの遅延が大きいので16F1938を32Mで動かしている (あくまでもMC14500Bを使うのが目的)

ICソケットに実装する前に電源のショートなど確認する 電池を入れて電源を供給、PWRのLEDで電源極性を確認 電源を切ってICを実装、向きがバラバラなので注意 J3はS;スロー側に設定、ジャンパポストはオープンで良い IN(J10)とOUT(J4)のb1、INのb2をGND(J6 3)、b3を+V(J6 1)に接続 (テスト用のプログラムだけならb3のみで良い、接続はプログラムに依存) 電源を入れて異常がなければPICkitを接続 (PICkitからは電源を供給しない・デフォルト) PICにプログラムしたらPICkitを外す RUNのスイッチを押すとプルグラムが動く

(PICで動かすなら3Vか4.5V) SW4を押すとCPUがリセットされる 同時にROMアドレスの上位が1になりEPROMの書き込んでない領域になる これによりCPUにはFが入力されるのでFLGFが出てぷrグラムカウンタが0になる 試験用のプログラムはDIPスイッチのNOT, AND, OR, XORをLEDに表示する

改善点 SW4とパラに0.1uFを入れておいた方が良い (電源ON時にリセット状態で止められる・動かしたいならSW3) RUNとWRITEのLEDを付けておいた方が良い データとして0,1、ラッチしたデータを読める入力があった方が良い (ジャンパするよう基板を作ってあるが、ジャンパポストを設けるべき) ラッチ4ビットのLEDに入れる抵抗は別回路な方が良い (外部I/Oで使うための抵抗と兼用になっている)

Parts

58
QtyValueFootprintReferences
17AE880Resistor_THT:R_Array_SIP9D1, D2, D3, D4, D5, D6, D7, D8, D10, D11, D12, D13, D14, D15, D16, D17 +1
1602x08Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_VerticalJ1, J2, J3, J4, J5, J6, J7, J8, J9, J10, J11, J12, J13, J14, J15, J16
510usr-Library:R_Axial_DIN0207_L6.3mm_D2.2mm_P2.54mm_VerticalR2, R3, R4, R5, R6
5GNDTestPoint:TestPoint_2Pads_Pitch2.54mm_Drill0.8mmTP5, TP6, TP7, TP8, TP9
40.1uusr-Library:C_Disc_P2.54mmC1, C2, C3, C4
4M2.6usr-Library:TestPoint_Drill3mmTP1, TP2, TP3, TP4
201x03Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_VerticalJ17, J18
24028usr-Library:DIP-16_W7.62mm_Socket_miniU1, U2
110kx8Resistor_THT:R_Array_SIP9R1
12764usr-Library:DIP-28_W15.24mm_Socket_miniIC6
14556usr-Library:DIP-16_W7.62mm_Socket_miniU3

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Questions

How big is the Cpu rom PCB?

It measures 99.1 × 99.1 mm and has 2 copper layers, 1.6 mm thick.

What parts does the Cpu rom use?

58 parts. 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 Cpu rom KiCad files?

From the jk1mly/cpu-1bit repository on GitHub, at the commit this page was made from: the board is cpu-rom.kicad_pcb and its schematic cpu-rom.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Cpu rom design in my own project?

Its repository publishes it under the BSD-2-Clause licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).