PEMX - External memory box

pozsarzs·zacchaeus·PEMX External memory box/hardware/pemx/pemx.kicad_pcb

PEMX - External memory box PCB layout, top view — open source board by pozsarzs

About the PEMX - External memory box PCB

PEMX - External memory box is an open source PCB design by pozsarzs, published on GitHub under the EUPL-1.2 license. It is a 2-layer board measuring 150.5 × 219.1 mm, with 79 components from 19 distinct parts.

Other key parts include the 74LS138, 74LS245, DS1833, 74LS173 and 74LS122. By type, the board carries 21 capacitors, 19 ICs, 16 jumpers, 14 resistors, 5 connectors and 2 diodes.

It belongs with the retro computing designs in this gallery.

From the project

8-bit microcomputer built from commercially available and home-built components

The PEMX is an external EPROM bank that connects to the computer (SC717 module) via two PIO ports. The device contains eight ZIF-type EPROM sockets that can accommodate the following types of EPROMs: 2764, 27128, 27256 and 27512 (and their "A" and CMOS variants). The device does not support the use of smaller EPROMs. Only one EPROM can be used at a time and they do not form a contiguous memory area.

Main components on the PEMX - External memory box

74LS138 74LS245DS183374LS17374LS12227512

PEMX - External memory box bill of materials (BOM)

79 components, 19 distinct parts.

Qty	Part	Footprint	Refs
2	74LS138	DIP-16_W7.62mm_Socket_LongPads	U1, U9
2	74LS245	DIP-20_W7.62mm_Socket_LongPads	U2, U3
1	DS1833	TO-92_Inline	U4
5	74LS173	DIP-16_W7.62mm_Socket_LongPads	U5, U6, U7, U10, U11
1	74LS122	DIP-14_W7.62mm_Socket_LongPads	U8
8	27512	DIP_Socket-28_W11.9_W12.7_W15.24_W17.78_W18.5_3M_228-1277-00-0602J	U12, U13, U14, U15, U16, U17, U18, U19
2	Conn_01x03_Male	PinHeader_1x03_P2.54mm_Vertical	J1, J5
1	Conn_01x06	Molex_KK-396_5273-06A_1x06_P3.96mm_Vertical	J2
1	Conn_02x13_Top_Bottom	PinHeader_2x13_P2.54mm_Vertical_Top_Bottom	J3
1	Screw_Terminal_01x02	TerminalBlock_bornier-2_P5.08mm	J4
16	Jumper_3_Bridged12	PinHeader_1x03_P2.54mm_Vertical	JP1, JP2, JP3, JP4, JP5, JP6, JP7, JP8 +8
2	LED	JST_XH_B2B-XH-A_1x02_P2.50mm_Vertical	D1, D2
2	L_Ferrite	L_Axial_L14.5mm_D5.8mm_P20.32mm_Horizontal_Fastron_HBCC	L1, L2
19	100n	C_Disc_D5.0mm_W2.5mm_P5.00mm	C1, C3, C4, C5, C6, C7, C8, C10 +11
1	220u	CP_Radial_D8.0mm_P2.50mm	C2
1	10u	CP_Radial_D5.0mm_P2.50mm	C9
10	1k	R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal	R1, R2, R7, R8, R9, R10, R11, R12 +2
1	33k	R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal	R3
3	470	R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal	R4, R5, R6

PEMX - External memory box design files

The KiCad project lives in the pozsarzs/zacchaeus repository on GitHub; these links point at the commit this page was built from.

PEMX - External memory box: common questions

How big is the PEMX - External memory box PCB?

The PEMX - External memory box measures 150.5 × 219.1 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the PEMX - External memory box?

79 components, from 19 distinct parts. The full bill of materials is listed on this page.

Where can I download the PEMX - External memory box design files?

From the pozsarzs/zacchaeus repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the PEMX - External memory box design in my own project?

Yes, under the terms of its EUPL-1.2 license, which pozsarzs chose for the repository.

More boards in zacchaeus

Similar boards