| ??? 08/10/08 11:17 Read: times |
#157371 - I think 8 or 16 bit is optimum Responding to: ???'s previous message |
If you poke around the www looking for a compiler called XPL0 (that last digit is a zero) you'll find a compiler that was written for the MCS6502 but which emulates a 16-bit machine. I hadn't actually sen the XPL0 language. Quite a lot of nice applications written using it. The last updates to the web page just a couple of days ago, so it is definitely active. I'm not sure what you mean by "emulating 16-bit" on the 6502, but I assume that you mean it will behave similarly to any 8-bit environment when using a C compiler, since the C standard requires the compiler to use at least 16-bit integers. That's the theory, though the results I've observed have often been disappointing. Which is why the war between RISC and CISC seems to have come to an end. Intel tried their NetBurst architecture to get RISC-like long pipelines but found that the power consumption can sky-rocket but the cost of every single stall made AMD chips run rings around it for random-jump applications. What's even more important, is that the author of that particular MIPS implementation has provided a simulator-compatible testbench, which will show you how to verify that your implementation works. I still think the MIPS core is a bit too high-end for my goal, i.e. running tiny applications at a non-critical pace. On your current PC, these will simulate the Z80 at many times the Z80's performance, yet provide perfectly useable code. Did write a Spectrum emulator somewhere around 1990. Ended the project (run out of time) somewhere when trying to figure out why it booted but presented all display output upside down :) Hand to slow down the emulation on a 25MHz 486 to get real-time speed. Too bad for me, I did the emulator in assembler so I can't just reuse the code, but it does work as a validation reference. I haven't brought myself totally up-to-date with Z80 tools, but M$ is quickly killing off the DOS prompt which should mean that both under Linux and Windows, a DOS emulator would be needed. An alternative is of course to go the full loop: With a Z80 emulator, a PC can emulate a CP/M machine and run any CP/M tool at a very high speed. The end user may not even have to see a command line - a GUI that picks up a file name and presents back a list-box with compilation results should be enough. A lot of CP/M tools are available for free. The question is if the CP/M OS is available for free. I have seen a number of download links, but for specific hardware and without any license information. Further, if you intend to add an MMU to an existing architecture, you may be disappointed with the performance. If you note, I do not want to emulate a processor with MMU. There would be no need/use since the target applications are expected to be small. And in an emulated environment, every memory access would be completely safe anyway - and the emulator would anyway have to catch accesses outside the available memory range. |
| Topic | Author | Date |
| Virtual or existing architecture for emulation | 01/01/70 00:00 | |
| Additional info about host/usage | 01/01/70 00:00 | |
| How about MIPS? | 01/01/70 00:00 | |
| VHDL | 01/01/70 00:00 | |
| take a look at the content | 01/01/70 00:00 | |
| I think 8 or 16 bit is optimum | 01/01/70 00:00 | |
| Maybe you should start with an ARM chip | 01/01/70 00:00 | |
| I2L sounds interesting | 01/01/70 00:00 | |
| It's probably best to check with the maintainers | 01/01/70 00:00 | |
| Doesn't seem to be a C to I2L | 01/01/70 00:00 | |
| The LLVM Compiler Infrastructure | 01/01/70 00:00 | |
| Since there's help available ... | 01/01/70 00:00 | |
| With the low price of 8-bit single chip MCUs... | 01/01/70 00:00 | |
| Slave processors not an alternative | 01/01/70 00:00 | |
| Users | 01/01/70 00:00 | |
| Probably debugging on PC | 01/01/70 00:00 | |
| Are you really going to do that! | 01/01/70 00:00 | |
| Existing building blocks helps | 01/01/70 00:00 | |
It hasn't been done for you but ... | 01/01/70 00:00 | |
| When I was in school ... | 01/01/70 00:00 |