Inspired by the 8-bit guy's project I've been thinking about how to build a cheap 65c816 system and I've decided to do it as an emulation.

Hunting around for a PIC32MZ development board I found this.

https://www.mikroe.com/mini-32-for-pic32mz

A 252MHz (415DMIP) 32-bit MCU with 1MB of flash, 512K of RAM a load of peripherals and a 32/64 bit FPU (time to put that coprocessor instruction to good use!). All on a 40 DIP carrier board for $29. The raw chip is only £7.42 and a hand solderable 64 TQFP if I wanted to use it directly.

I think I'll provide 384K of RAM to the emulator and 128K of (OS, Basic, Forth, etc.) ROM image with a small 4K boot ROM copied into bank 0 RAM at startup (00:f000-00-ffff).

For video I'm thinking of 800x600 SVGA monochrome (like an original Mac but better than 512x342). Driven from the PIC by DMA'd SPI it should use minimal CPU time. PS/2 mouse and keyboard inputs (you can still buy them!).

I'm not sure how fast i can get the emulator to run but I suspect over 8Mhz equivalent is possible.

At least two UARTs and an I2C bus via a slightly extended instruction set (via COP or WDM maybe).

As it will run at 3v3 interfacing to an ENC28J60 networking chip would be relatively easy.

For sound I was thinking of two SN76489 chips (3 stereo or 6 mono voices) but I'm not sure how to mix those.

_________________
Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs

Interesting - will you be writing a new '816 core? It would be great to have an '816 test suite!

I already have a fairly well tested C++ 816 emulator here

https://github.com/andrew-jacobs/emu816

I'm going to port if over and tweak it a bit.

_________________
Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs

Sounds good! I should have a look at that. Having the FPU hooked in would be a nice touch.

Nice to met a fellow '816 emulator author! I've also got a C++ implementation as part of my XGS project (https://github.com/jmthompson/xgs). It's something I've been tinkering with now for the last 20+ years (XGS was first released as pure C code way back in 1996). It's not nearly as fast as yours but it does have support for interrupts and variable memory maps, and is capable of booting and running Apple IIGS applications.

I'll have to check yours out when I get some free time from my current SBC project.