fpga

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It's an Apple Lisa, on a FPGA
2 months ago
- Apple Lisa was the precursor to the Macintosh, but was expensive and a commercial failure, with few surviving units.
- A new FPGA-based replica by [AlexElectronics] supports both original Lisa peripherals (keyboard, mouse) and modern interfaces (USB, HDMI, SD card).
- The project includes a 40-pin DIP UART chip due to lack of a pre-built UART for the FPGA, and will be open-sourced on GitHub.
- Comments note that the Lisa's serial number DRM protected software, but the FPGA can be programmed to bypass it, preserving old I/O like CRT monitors.
- The Lisa was essential for early Mac development as it ran the Mac SDK, and later could run Mac software via MacWorks; the Macintosh XL was a modified Lisa 2.
- Copy protection often harms legitimate users, and the Lisa's DRM is seen as a minor issue since the machine was a commercial flop.
Mister - Recreates classic computers, video game consoles, and arcade machines
2 months ago
- MiSTer FPGA is an open-source project that recreates classic computers, consoles, and arcade machines on modern hardware.
- It enables software and game images to run as on original hardware while supporting peripherals like mice, keyboards, and game controllers.
- The system uses the DE10-Nano FPGA board and outputs to TV/monitor via HDMI, with expandability through add-on boards such as USB hub, SDRAM, and I/O boards.
- The project is actively developed with regular new cores, features, and bug fixes.
- Additional resources include documentation, a Discord server, X/Twitter account, forums, a GitHub Wiki, and a video guide.
Running Doom on Our Custom CPU and Going Viral
2 months ago
- The team designed a custom CPU from logic gates, adapted DOOM source code, and ran it on an FPGA at 0.7 FPS initially.
- Major challenges were memory size (DDR3 vs BRAM) and speed; they implemented two caches (ICache and DCache) with a memory arbiter to handle DDR3 latency.
- Porting DOOM revealed CPU bugs such as infinite loops, incorrect immediate calculations, and cache overwrite issues; debugging required isolating parts of the program.
- Hardware issues included unstable DDR3 interface (solved with Clock Domain Crossings and FIFOs) and keyboard input problems (used UART forwarding from a laptop).
- Optimizations like raising clock speed, fixing fetch stage inefficiency, adding multiplication instructions, pipelining cache reads, and enabling compiler optimization raised FPS from 0.7 to 15-20.
- The team plans to implement out-of-order processing and better memory access to reach 30 FPS, and possibly port Quake 2 after building a basic GPU.
AMD pivots from HBM to LPDDR5X for new Versal Gen 2 memory on package chips
3 months ago
- AMD announces Versal Premium Gen 2 Memory on Package SoCs with on-package LPDDR5X for integrated, turn-key solutions.
- The pivot from HBM to LPDDR5X is driven by HBM supply shortages due to AI boom demand, leading to Versal HBM discontinuation.
- On-package memory strategy shift addresses long-term availability issues, as HBM has shorter production cycles than DDR technologies.

It's an Apple Lisa, on a FPGA

Mister - Recreates classic computers, video game consoles, and arcade machines

Running Doom on Our Custom CPU and Going Viral

AMD pivots from HBM to LPDDR5X for new Versal Gen 2 memory on package chips