ao486

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Sorgelig
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Re: ao486 Performance Technical Discussion

Post by Sorgelig »

4 word bursts is ineffective - many wait states. 64, 128 words burst - this will be effective bursts.
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Re: ao486 Performance Technical Discussion

Post by nightshadowpt »

That was a very interesting read... it still fascinates me how old hardware can still spark such discussions.

Although I am very interested in seeing the final result of this discussion (that will hopefully end up in having a quicker AO486 core) I would like to ask a question/request:

Would it be possible (without much effort) to add options to the GUI to control both the Ram size and the Speed (to decrease)?

Given my very limited knowledge, it should not require the creation of any additional modules, just an adjustment in the settings. Is that correct, or will it be a massive undertaking?

These two changes seem quite simple, but would contribute to increase significantly the core compatibility with older software.

Thanks.
Last edited by nightshadowpt on Fri Jan 24, 2020 3:55 pm, edited 1 time in total.
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Re: ao486

Post by nightshadowpt »

mahen wrote: - any tip on how to properly set up the MT-32 ? (<--- OK, regarding this one I clearly probably have to read the whole thread before)
You've probably solved this by now, but since I was also banging my head around to get this one working, I'll leave here for future reference what I did to get the MT-32 working:

- On the Core, change your "UART mode (midi)" options to "MidiLink: Local" and "type: MUNT"
- Download and copy SoftMPU to your DOS HD (https://bjt42.github.io/softmpu/)
- Run SoftMPU with the command "SOFTMPU.EXE /SB:220 /IRQ:5 /MPU:330 /OUTPUT:COM1"

And it's done.

Now you just need to select the MT-32 as the sound device on your game setup.

P.S.: please note that some Sierra games take a long time to load (2-4 minutes on a black screen) on the MT-32 mode, so give it time...
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Re: ao486 Performance Technical Discussion

Post by Newsdee »

I am getting corrupted graphics in Budokan and Metal Mutant. Is anybody else experiencing those?
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Re: ao486 Performance Technical Discussion

Post by sofakng »

I wanted to say thank you SO MUCH for working on improving the ao486 core. This is by far the core I'm most excited and hopefully about!

I've thought about building a "retro" 386 or 486 machine for DOS gaming but I'd much rather have an FPGA solution.

Again, thank you very much and I'm sure there are many other people who also appreciate your work!
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Re: ao486 Performance Technical Discussion

Post by Lroby74 »

sofakng wrote:I wanted to say thank you SO MUCH for working on improving the ao486 core. This is by far the core I'm most excited and hopefully about!

I've thought about building a "retro" 386 or 486 machine for DOS gaming but I'd much rather have an FPGA solution.

Again, thank you very much and I'm sure there are many other people who also appreciate your work!
If you wish like alternative to try, there is PCem that is IMHO best DOS machines (8088 to Pentium 1) emulator for modern PCs, i love it!
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Re: ao486 Performance Technical Discussion

Post by crocky »

If you are looking for a 386 to run games before 1993 mainly, ao486 is fine.
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Re: ao486 Performance Technical Discussion

Post by dshadoff »

Are there currently any efforts at making this core support PC-88/PC-98 Japanese systems, or just generic IBM derivatives ?
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Re: ao486 Performance Technical Discussion

Post by calvinmorrow »

nightshadowpt wrote: Would it be possible (without much effort) to add options to the GUI to control both the Ram size and the Speed (to decrease)?

Given my very limited knowledge, it should not require the creation of any additional modules, just an adjustment in the settings. Is that correct, or will it be a massive undertaking?
I think adding some configuration options to set the CPU frequency may be something I'd be interested in looking into in the future if the caching/RAM efforts yield some speedups. Currently the ao486 core runs about the equivalent speed of a 386/16 MHz even though its clocked at 90 MHz. A fair number of the games I know of that rely on clock cycles for timing run best somewhere in the 386 performance envelope so adding options for keeping that target _if_ we get beyond it is something I'd personally be interested in.

The RAM is a little more complicated. ao486 uses the onboard RAM (64 Megabytes of it) for memory access. This is convenient but also has its downsides. I'm not sure how easily that can be changed in a semi-dynamic fashion. The more I learn about the core the more interested I am in trying to use the addon SDRAM at some point to compare performance. I imagine it would be doable to artificially limit the size though I'm not aware of any reasons for doing so. Is there a particular reason for wanting to limit the RAM size? What's the use case? What software has issues with the 64 MB currently?
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Re: ao486 Performance Technical Discussion

Post by calvinmorrow »

dshadoff wrote:Are there currently any efforts at making this core support PC-88/PC-98 Japanese systems, or just generic IBM derivatives ?
Not that I'm aware of. The ao486 core is fairly complicated and a little difficult to change for a number of reasons. The original author actually used a Java tool to interpret a combination of text and script files to produce the files that are actually compiled for the FPGA to consume. While its an impressive technical feat, it doesn't lend itself well to change control (git) and is also a bit harder to tweak smaller things.

Personally I'm trying to reimplement code sections in Verilog for easier change and modification. That means more initial work but would likely be easier for other contributors to pick up rather than trying to use a large odd toolchain.
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Re: ao486

Post by comatron »

Hi guys. I cant get the ao486 core outputting an analog vga signal that my screen eats. Can someone help? First i thought its the scandoubler option i used in the mister.ini but disabling that does the same. Screen says "H26.7khz V:59.9hz out of range". Would be very cool not to have the vga connected to the scale cause of latency. If not possible, please let me know so ill continue with the scaler-option. Thanx guys.
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Re: ao486

Post by funkheld »

Hi good afternoon.

I would like to get the ao486 up and running.
I don't have a boot disk.

where can you get a boot disk for the MiSTer-ao486 for this system.

can you also play the cga mode with it, because in the
description stands for vga standard.

Thank you.
greeting
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Re: ao486

Post by comatron »

yeah CGA is possible and bootdisks of all DOS kind can be found here: https://winworldpc.com/product/ms-dos/622
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Re: ao486

Post by nightshadowpt »

funkheld wrote: can you also play the cga mode with it, because in the
description stands for vga standard.
Some CGA games may play a bit too quick though...
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Re: ao486

Post by funkheld »

hello, I have now taken msdos 3.1 and it works.

is there only drive "A" in the MiSTER?

how can you make your own disc with msdos on it and your own game com.
with which program for window10 please?



Thank you.
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Re: ao486

Post by Sorgelig »

funkheld wrote:hello, I have now taken msdos 3.1 and it works.

is there only drive "A" in the MiSTER?

how can you make your own disc with msdos on it and your own game com.
with which program for window10 please?
You can use any empty file of required size as VHD. Then get bootable floppy image with required dos files to partition and format the HDD. Then boot from floppy in ao486 and prepare the HDD there. After creating and formatting HDD, you can mount this image on Windows using some image mounting tools and fill it with files you want.

Currently only a single floppy is supported.
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Re: ao486

Post by comatron »

create a vhd (virtual hard disk) with the windows integrated partition tool. max 2gb - fat 16. doubleclick in windows to mount that. copy stuff on it. move vhd to sd-card. mount as hd.
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Re: ao486

Post by Sorgelig »

I strongly suggest to partition and format the HDD on MiSTer. Otherwise imported image may have incompatible partition table or partition format.
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Re: ao486

Post by reflex »

Not sure if anyone finds this useful, but I was able to install and configure FreeDOS on this core and it seems to work fairly well. Still have some things to figure out like sound and terminal for PPP, but it's a much more modern DOS that should be fully backwards compatible.

http://www.freedos.org/

Also the licence should make distribution of configured VHD's (without games or other non OSS apps) legal: http://wiki.freedos.org/wiki/index.php/ ... e_software
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Re: ao486

Post by funkheld »

Thanks for your help.
have now created an x86.vhd under win10.
then I formatted it under "fat16" under win10 and hd is hd is the MBR.

then I copied it from x86.vhd to hd.vhd.

the hd.vhd was recognized by the MiSTer.

I started the msdos from disk
the HD can be seen above as secondary hdd
boot from floppy in ao486 and prepare the HDD there.
how can you prepare the hard disk in the ao486? the msdos started in the ao486 and the hd can also be seen in the picture.
I cannot call them by name.
you can mount this image on Windows using some image mounting tools and fill it with files you want.
i have a vhd file.
how can it be filled?

Thank you.
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Re: ao486

Post by comatron »

you have to think dos for that :D mount the hd as primary and run dos installer from floppy. but before installing dos with the installer quit it and use "fdisk". create primary partition, set the boot flag. back in dos after reboot format the drive with "fromat c:"

install dos on that drive (primary vhd)

boot next time from HD. there you have a stock/vanilla dos. tweak it as you like (google for the good old dos optimizations like mousedriver etc.)
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Re: ao486

Post by comatron »

reflex wrote:Not sure if anyone finds this useful, but I was able to install and configure FreeDOS on this core and it seems to work fairly well. Still have some things to figure out like sound and terminal for PPP, but it's a much more modern DOS that should be fully backwards compatible.

http://www.freedos.org/

Also the licence should make distribution of configured VHD's (without games or other non OSS apps) legal: http://wiki.freedos.org/wiki/index.php/ ... e_software
can you upload that image somewhere? i failed installing dos 7 and freedos - would be nice.
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Re: ao486

Post by reflex »

comatron wrote:
reflex wrote:Not sure if anyone finds this useful, but I was able to install and configure FreeDOS on this core and it seems to work fairly well. Still have some things to figure out like sound and terminal for PPP, but it's a much more modern DOS that should be fully backwards compatible.

http://www.freedos.org/

Also the licence should make distribution of configured VHD's (without games or other non OSS apps) legal: http://wiki.freedos.org/wiki/index.php/ ... e_software
can you upload that image somewhere? i failed installing dos 7 and freedos - would be nice.
Sure, I haven't set everything up yet but if you are willing to do that yourself I can certainly upload a bootable VHD as is (and if you want to get ther est working I'd be thrilled to not have to figure it out). The setup did require rerunning several times to complete successfully, I am not sure why but I noticed it wasn't always failing at the same point so I kept going until it went through. It seems reliable on operation and I haven't had any failures since I got it working.

Right now I have it on a 500MB VHD, I was considering reducing the size and using a D drive for apps. What do you think is most appropriate for a distributed VHD and I'll do that.
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Re: ao486

Post by funkheld »

Thanks for your help.

Hi good afternoon.

I can not do it with the hd.

I can't write on it.
I would like the HD as a secondary drive.

Thank you.
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Re: ao486 this ok

Post by funkheld »

Hi good afternoon.

have now managed to create a msdos-start-hd with 10mb.
I set this up as the primary hd to start with.
HD made with window10, but without format (fat16).
I have the format from the msdos disk to the hd in the mister.

greeting


is ok...
Last edited by funkheld on Fri Jan 31, 2020 7:10 pm, edited 1 time in total.
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