nand2mario
@nand2mario
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FPGA and retro gaming dev. Author of NESTang and SNESTang.
Joined August 2022
Just released TangCore 0.9 for #tangconsole 🎁 🎉. This adds the first computer core, PC/XT, to the list of console core NES,SNES,GBA,Genesis/MD and SMS. Also added: on-board SD card support for upcoming v1.1 boards. Improved 138K stability. Get it:
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1993 mars.exe demo running under ao486-sim. `demo\mars.exe` on the dos6.vhd virtual disk.
Introducing ao486-sim 🚀 - `make sim` and watch the ao486 Verilog CPU booting DOS 6.22. A good tool for learning CPU design and how PCs work in general. Github:
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Just pushed an update to allow persisting of hard disk writes by pressing the CMD-s or WIN-s key, with the help of SystemVerilog DPI. Now the QBasic or Turbo C programs you write are actually saved. :).
Introducing ao486-sim 🚀 - `make sim` and watch the ao486 Verilog CPU booting DOS 6.22. A good tool for learning CPU design and how PCs work in general. Github:
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True. It’s more of a by-product of getting ao486 to work on non-Intel FPGAs. Also RTL simulations are “closer to the silicon” and better for learning hardware/chip designs.
@nand2mario At this point you might as well just runs Bochs which IIRC is the foundation of the core and why is so badly optimized and huge. There’s a Pentium Pro class core floating around for years but is just the netlist, it works but no peripherals, just uart.
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Introducing ao486-sim 🚀 - `make sim` and watch the ao486 Verilog CPU booting DOS 6.22. A good tool for learning CPU design and how PCs work in general. Github:
DOS 6.22, in ao486 simulation, running on Mac at 0.7 FPS. 🤪. Now I can compare my z86 with ao486.
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DOS 6.22, in ao486 simulation, running on Mac at 0.7 FPS. 🤪. Now I can compare my z86 with ao486.
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OK I've uploaded my from-scratch 80286-like softcore CPU to github: 🚀 It is still a WIP. But it should be fairly complete, at least in simulation. 5-stage pipeline design like the 80486: Fetch, Decode1, Decode2, Execute, Write-Back.
github.com
A pipelined 80286-class FPGA softcore CPU. Contribute to nand2mario/z86 development by creating an account on GitHub.
My 286-class CPU (real-mode only) is finally working in sim and we have PC-AT BIOS, VGA and IBM Basic working.😀 The CPU is written from scratch and uses a 5-stage pipeline, aiming to be fast enough to run early 90's games. The final core will be in between ao486 and PCXT_MiSTer.
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My 286-class CPU (real-mode only) is finally working in sim and we have PC-AT BIOS, VGA and IBM Basic working.😀 The CPU is written from scratch and uses a 5-stage pipeline, aiming to be fast enough to run early 90's games. The final core will be in between ao486 and PCXT_MiSTer.
Trying to make something new for 8086/8088. Finally there's progress in coverage tests after many hours of work. x86 is such a complicated beast.😅😅
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The first thing I implemented was the instruction fetch buffer. Each 8086 instruction could be 1 to 10 bytes. Oh my. Took me a few attempts to parse the instruction in as few cycles as possible….
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Trying to make something new for 8086/8088. Finally there's progress in coverage tests after many hours of work. x86 is such a complicated beast.😅😅
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And the refactored firmware (C++) is here:
github.com
Contribute to nand2mario/firmware-bl616 development by creating an account on GitHub.
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For people interested in the source code, the new PCXT core is here: Difference from PCXT_MiSTer: a CGA color framebuffer, a new SDRAM controller (the original one is messy), verilator simulator.
github.com
IBM PC/XT for Sipeed Tang FPGA. Contribute to nand2mario/pctang development by creating an account on GitHub.
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For this version the firmware design was also refactored, moving from C to C++ for better productivity. The code is still mostly C, but things like C++ string and vectors do speed things up. There's now in game menus and a command console.
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The first version of PC core is roughly an early '80s 8088 machine, with CGA graphics, 10Mhz 8088 CPU and 1MB of memory. It is a good fit to experience the early days of PC gaming and applications. I had fun trying some BASIC programs and games.
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The new 1.9.11.02 Gowin IDE seems to be solid, improving timings significantly in some cases.
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Working on the PC/XT core. Added a in-game menu to mount floppy images. This is almost ready for a basic first release. 🍓 Also refactoring the firmware at the same time, making things more maintainable.
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Nice!.
SNES on FPGA feat. TangConsole.実装できた！. TangNano20KだとサウンドDSPが入らなくて音無しだったけどこっちは138Kもあるので、スーファミ全実装が可能か不可能かで言えば、余裕です（LUT使用率19%）. はじめ動作が不安定なことがあったけど入出力遅延制約付けたら安定したし
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The PC XT is a simple machine by modern standards. But porting this core turns out to be quite some work. The floppy/hdd requires new two way communication between mcu and fpga. Keyboard is also non-trivial as this is pre-PS/2. Should make future computer cores easier tho. :).
This is how donkey.bas (PC XT 🖥️, 1982) looks on #tangconsole upcoming PCXT core. CPU, floppy💾, USB keyboard, CGA are all working now. Working on hdd and sound. 🎈
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