MiSTer FPGA Forum

Hey, so I got the DE-10 Nano and MiSTer Add-one USB.
I also followed the instructions to get the AO486 core on the unit, and with the pre-build DOS 6.22 setup found here: https://www.jamesfmackenzie.com/2021/03 ... isk-image/

However, when I’ve tried to run a game I’ve building using DJGPP with Allegro, the program hangs at the console immediately after execution.

I’ve tried another game written in the early 90’s (Galactic Battle) and it worked fine. Strange.

I tried another game compiled with DJGPP/Allegro, and it also hung.

I got down to a simple “Hello World” program compiled with DJGPP only. Just stdio and no explicitly linked libraries. Freaking Hello World didn’t even run without hangcrashing. And I’ve tried it on all three memory configurations.

I’ve included the 32-bit DOS extender CWSDPMI.EXE with my programs, as it’s required to run DJGPP-compiled stuff. Does anyone here know if I’m doing something wrong? Or if there’s a compatibility issue I’m missing?

I've had the same issue. Tried running three or four different programs I wrote myself in DJGPP/Allegro years ago using the ao486 core to no avail.

They do run in DOSbox, though programs with joystick inputs get stuck in a direction making them unplayable.

The latest I have read on this forum is some DOS extenders, at least dos/4gw, iirc, have issues running on ao486. My guess is a similar compatibility issue.

ash2fpga wrote: ↑Sat Jun 26, 2021 1:07 pm The latest I have read on this forum is some DOS extenders, at least dos/4gw, iirc, have issues running on ao486. My guess is a similar compatibility issue.

That would explain it, for sure. Looks like it’s back to the drawing board for my project.

Actually, I’m not sure how long it would take these guys to get DOS extenders running. Maybe it makes sense to sit back and wait.

Perhaps memory mapping is wrong... or memory report

There is a lot of shit wrong with this core, otherwise everything would be working

A lot of TSR's and anti-debug routines wont work properly either from my experience. My guess at this point is that it has something with the IVT (Interrupt Vector Table). From my limited knowledge regarding DOS-extenders they would use or redirect INT's and add their own.

Now dosbox has a nice debugger, does the AO486 have an embedded debugger or do we revert to good ol' Softice?

Yeah I came to same conclusions: The core is not usable in its current state. Sadly.