This repository supports the IMSAI 8080 Reproduction Project
The IMSAI 8080 Reproduction Project (I8PP) is a project to recreate the original kits that became the IMSAI 8080 computer from the mid 1970s. This is an 8080A based 8-bit computer implemented in the S-100 architecture. The IMSAI 8080 is considered the first "clone" computer as it copied from and improved upon on the ALTAIR 8800. We are repoducing the original PCBs and making them available as kits. We are working on the reproduction case as well.
In December 2024 the first kit, the CP-A (control panel) shipped and is being assembled by the end users. The feedback on this initial kit has been very positive.
As of December 2024 the I8PP project status is:
- CP-A (Control Panel) - Kits are shipping
- MPU-A (8080A CPU) - Schematic capture and the PCB layout are completed and tested. Several have been built. This kit will start shipping in early 2025.
- SIO-2 (dual RS-232 / 20mA) serial communication card - Schematic capture and the PCB layout are completed and tested. Several have been built. Will ship in 2025.
- PIO-4 (4 x 8-bit) parallel I/O ports - Schematic capture and the PCB layout are completed and tested. Several have been built. Will ship in 2025.
- EXP-22 (mother board, 22 slot) - Schematic capture and the PCB layout are completed and tested. Several have been built. Will ship in 2025.
- EXP-4 and EXP-6 (mother boards, 4 and 6 slot) - Schematic capture and the PCB layout are completed and tested. At this time we don't have plans to sell this kit.
- Case - This is the iconic blue sheetmetal case the system components are mounted in - The mechanical designs are completed and we are working RFQ with various manufactures.
- Components - Sourcing vintage components can be difficult - we have a wide selection of ICs, cables and other parts that can be used as part of an original IMSAI 8080 restoration.
Why the IMSAI 8080?
- The IMSAI sits at the point in time when a sufficinetly powerful computer became available that, in the end, the user could do useful work with. It marked a time when a set of standards (S-100) allowed 3rd party software and hardware developers to join the market selling into the hobbiest community. Word processing, games, accounting, process control, experimentation, programming in assemble, C, PASCAL and FORTRAN were within grasp.
- This era of home computing provide the ability to fully understand in depth the full computer. Every IC can be understood. The electronics design can be understood. Working in 8080 assembly language can be understood. An OS like CP/M can be modified and compiled by the end user; this was expected when you added hardware to the system.
- I (RetroTechReboot) find the current world of softward and hardware development to be beyond the full grasp of hobbiests and even profesionals. Modern tools have become very complex; you are often abstracted away what's happeneing at the lowest level. Libraries, abstractions, APIs etc. all focus on software however the complexity behind them tends to be hidden and further, how it interacts with the hardware tends to be hidden.
- A solid grasp of the electronics and the software that supports it at the lowest level can help build a solid foundation for modern programmers that I feel is lacking in most CS programs.
About the I8PP project.
- Neil (AKA RetroTechReboot) started the project in late 2023 after aquiring an unbuilt NOS IMSAI 8080 kit.
- Robert (parastream.com) has rebooted IMSAI as a business.
- Together Robert and Neil are the "IMSAI 8080 Reproduction Project"
- The kits are full reproduction down to the individual ICs. Nothing is emulated.
- Our goal is to sell full kits for the IMSAI 8080 Computer. These are full reproductions of the original system. All components are backwards compatable with the original IMSAI can be used for restoration and repair work.
- All of the kits and components can be built using the original manuals IMSAI published in the 1970s, These kits are full reproductions and use the same ICs as the original system.
- We provide cleaned up versions of the manuals and add supplimental information that can be used to make the kit building experience a little easier.
- In the end we want you to be able to experience what it was like in in the 1970s to have a big box show up and to find it full of components, manuals, PCBs, hardware, case parts etc. that you can assemble into a working IMSAI 8080 computer.
- Both Robert and I are involved in all aspects of the project that includes: Schematic capture, PCB layout, vendor management, parts aqusistion, stock and inventory management, kitting, mechanical design, support, sales, manufacturing, testing etc.