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Re: CGA pseudo-graphic modes

What are the specs of your computer, particularly your cpu? Intel(R) Core(TM) i5-2520M 2.50 GHz 6 GB RAM Yeah, sorry. That CPU is 14 years old. Modern phones are faster. I know upgrading your computer is not a luxury everyone has. But there's only so much I can do. I will continue to try to …

Re: CGA pseudo-graphic modes

SoftCat wrote: I really like MartyPC, but it works very slowly for me. I can't debug the game on it. Maybe there is some option to speed it up without losing the CRTC tricks? What are the specs of your computer, particularly your cpu?

Re: OPL2 (adlib) status port timing?

Then how does ISA timing work? I know the bus is apparently running at 14MHz, but is anything known how timing behaves with inserted waitstates on 808x/Vx0 or 286+ CPUs running at various speeds? Simply wait for the next tick or tick multiple (as in modulo 3 being zero for example to get 808x …

Re: A Test Suite for the Intel 8088 CPU

A test suite for the 8086 is now available also. It offers little advantages over the 8088 set if you're just looking to validate instruction correctness, but those interested in cycle accuracy for the 8086 might find them useful as they capture per-cycle bus activity, including the 8086's BHE pin …

Re: MartyPC

MartyPC 0.4.1 has been released. Mostly bugfixes, but we added the V20's 8080 emulation mode and some additional geometries for the Xebec controller. I fixed the static compilation so it should no longer need any MSVC runtimes.

Re: MartyPC

Really? Isn't it implementing the 80186 instruction set, which defined the #UD exception for the first time? Edit: Checked both NEC V20 and V30 manuals. Indeed, it implements 80186 instructions, but unlike the 80186, no #UD vector is implemented? Doesn't that break 80186 software? Why would said …

Re: MartyPC

OK. That should be doable. What happens with undefined ('-' marked) instructions? Do they throw an #UD exception? V20 has no UD. They do weird things. My theory is that they end up in undefined microcode slots. I'm currently converting the CPU tests to a binary format, with included ANSI C to read …

Re: MartyPC

Regarding the 8080 mode, I found this: https://pastraiser.com/cpu/i8080/i8080_opcodes.html Is that actually what the 8080 manual specifies for it's instructions (in the NEC V20/V30 8080 mode)? What about the instructions marked with an asterisk? See attached chart. The undefined instructions on V20 …

Re: MartyPC

GloriousCow, just read your latest blog post about the Lake Effect - quite impressive, and a very interesting read! Thanks, glad you liked it! I need to blog more - I have another one coming out soon about what I've learned so far about 16-bit bus access, speaking of the 286 and all. The mechanism …

Re: MartyPC

To be honest, my "abysmal" comment was more in comparison to others, and I don't have any working original 4.77mhz 8088 machines any more, and I'd forgotten how slow they are. Okay. I apologize if I've been misreading your tone, but I feel like I've been on the defensive this whole thread. Any …

Re: MartyPC

Sure: MSDOS 2.11 booted on MartyPC (WEB) 0+ 632 632+ 603 1235+ 603 1838+ 638 2476+ 603 3079+ 604 3683+ 603 4286+ 603 4889+ 638 5527+ 603 6130/ 10= 613 Seems pretty abysmal, but I don't know how indicative a "web" application would be over the native MartyPC running on my machine. Here are the …

Re: MartyPC

I've got some ideas which should help a lot with these and will add command options to the test to allow me to set it up in different ways. Once I've implemented them, I will re-run the tests on all the platforms I have and see how much things change. These tests are interesting, but would you mind …

Re: MartyPC

Seems pretty abysmal Considering I have no idea what the numbers you are dumping into this thread mean, I can't even agree or disagree with you. , but I don't know how indicative a "web" application would be over the native MartyPC running on my machine. Does the WEB version download some sort of …

Re: MartyPC

DaveDDS wrote on 2025-05-23, 11:52: (Forgot one) MS-DOS Player (i8086) for Win32 console Can you try the web version of MartyPC at least?

Re: MartyPC

Makes sense. Is there a way you could turn that core emulation into a library? Not easily, no. At least, not as a clean "drop-in" CPU with a C FFI. There are a bit too many internal integrations between the CPU and peripherals, maybe I could factor those out, but there's still an inversion of …

Re: MartyPC

I've yet to dip my toes into Rust and really don't know much about it. What about it made you more productive? I've stuck with C because I can port whatever I write to anything from the latest i9 running Windows down to an 8086 or a microcontroller or an old PowerPC. Iterators are nice. Option …

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