ISA EMS 2Mb
About the ISA EMS 2Mb PCB
ISA EMS 2Mb is an open source PCB design by hkzlab, published on GitHub under the CC-BY-NC-4.0 license. It is a 2-layer board measuring 104.1 × 102.9 mm, with 41 components from 17 distinct parts.
Other key parts include the AS6C4008-55PCN, 74HCT688, 74HCT139, 74HCT32 and 74HCT04. By type, the board carries 18 capacitors, 15 ICs, 3 resistors, 2 connectors and 1 diode.
It belongs with the retro computing designs in this gallery.
From the project
ISA 8bit EMS 2Mb expansion card
This is a reimplementation of the lo-tech.co.uk 2Mb ISA EMS board with the following changes:
- All thru-hole instead of SMD, while retaining a rather compact format - Activity led to indicate when the memory is accessed
I take NO responsibility for what happens if you decide to build and use this card. Your computer might crash, catch fire or be destroyed in other nasty ways. Also, as this card is mostly based on the work of others, You're encourauged to take what you deem fit from this, and use it in your projects!
Main components on the ISA EMS 2Mb
ISA EMS 2Mb bill of materials (BOM)
41 components, 17 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 4 | AS6C4008-55PCN | DIP-32_W15.24mm | U3, U4, U5, U6 |
| 2 | 74HCT688 | DIP-20_W7.62mm_LongPads | U7, U8 |
| 1 | 74HCT139 | DIP-16_W7.62mm_LongPads | U9 |
| 1 | 74HCT32 | DIP-14_W7.62mm_LongPads | U10 |
| 1 | 74HCT04 | DIP-14_W7.62mm_LongPads | U11 |
| 1 | 74ACT245 | DIP-20_W7.62mm_LongPads | U12 |
| 1 | 74HCT138 | DIP-16_W7.62mm_LongPads | U17 |
| 4 | 74HCT573 | DIP-20_W7.62mm_LongPads | U18, U19, U20, U21 |
| 1 | ISA BUS | Conn_Edge_PCB_ISA8 | J1 |
| 1 | EMS Address | PinHeader_2x04_P2.54mm_Vertical | J2 |
| 2 | MountingHole_Pad | Hole_3mm | H1, H2 |
| 1 | EMS in use | LED_D3.0mm_Clear | D1 |
| 2 | 10uF | CP_Radial_D5.0mm_P2.50mm | C5, C6 |
| 16 | 100nF | C_Disc_D6.0mm_W2.5mm_P5.00mm | C7, C8, C9, C11, C12, C13, C14, C15 +8 |
| 1 | 470 | R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R3 |
| 1 | 10k | R_Array_SIP5 | RN2 |
| 1 | 10k | R_Array_SIP9 | RN3 |
ISA EMS 2Mb design files
The KiCad project lives in the hkzlab/ISA_EMS_2Mb repository on GitHub; these links point at the commit this page was built from.
- LayoutISA_EMS.kicad_pcb
- SchematicISA_EMS.kicad_sch
ISA EMS 2Mb: common questions
How big is the ISA EMS 2Mb PCB?
The ISA EMS 2Mb measures 104.1 × 102.9 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the ISA EMS 2Mb?
41 components, from 17 distinct parts. The full bill of materials is listed on this page.
Where can I download the ISA EMS 2Mb design files?
From the hkzlab/ISA_EMS_2Mb repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.
Can I use the ISA EMS 2Mb design in my own project?
It is published under CC-BY-NC-4.0, which limits how it may be reused; read the license before building on it.
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