MiSTer PCXT

[kitune-san]

I noticed during the process of working on it that it needs some more improvement for stable operation.
Freeze occurs during disk read.

The image is when trying to read FreeDOS x86BOOT.img.

2022-08-23 232256.png

I will create a temporary branch.
Please help!

The code before the rebase was saved in the following branch

Notes.
Please set the FDD disk every time after reset. If not, the drive does not seem to recognize it.

https://github.com/kitune-san/PCXT_MiSTer/tree/fdd-work

[spark2k06]

I noticed during the process of working on it that it needs some more improvement for stable operation.
Freeze occurs during disk read.

The image is when trying to read FreeDOS x86BOOT.img.

2022-08-23 232256.png

I will create a temporary branch.
Please help!

The code before the rebase was saved in the following branch

Notes.
Please set the FDD disk every time after reset. If not, the drive does not seem to recognize it.

https://github.com/kitune-san/PCXT_MiSTer/tree/fdd-work

Perfect, thanks, as soon as I can I will check it and see how to organise it initially.

[kitune-san]

I noticed a large number of timing constraint violations with the floppy drive.
Tomorrow I will focus on this.

2022-08-24 001505.png (70.96 KiB) Viewed 13181 times

[Caldor]

So much progress Nice to see. I will experiment some more tomorrow.

[MicroCoreLabs]

I believe you that the UART flow control signals are connected, but I wonder if they are enabled on the host side. They may default to disabled. One easy check is to see if they toggle using SignalTap.

[spark2k06]

I believe you that the UART flow control signals are connected, but I wonder if they are enabled on the host side. They may default to disabled. One easy check is to see if they toggle using SignalTap.

You're right, I'll try to find out.

[spark2k06]

I noticed a large number of timing constraint violations with the floppy drive.
Tomorrow I will focus on this.

2022-08-24 001505.png

I have to make reorganisations in the code before including this progress, please keep moving forward in getting stability from your branch, and we'll merge it later.

Thank you!

[Malor]

That's weird. Has this core implemented something like an A20 gate or an HMA area?

The 8086/8088 had neither function. The HMA was created by a bug in the 80286, and the A20 line implemented a workaround to toggle it on and off, because a lot of DOS software broke when it was enabled.

It's one of the best hardware bugs ever. Free almost-64K was kind of a big deal. It was so useful that all later x86 chips preserved the behavior.

[NightShadowPT]

Good to see this core released!

Great job!

Is there any equivalent to the eXo/Flynn Top 300 DOS Pack for this core? (focusing on 8086 games)

[akeley]

Is there any equivalent to the eXo/Flynn Top 300 DOS Pack for this core? (focusing on 8086 games)

https://archive.org/details/tdl-hdd

This is a different concept than the curated & tested stuff flynnsbit's doing (I believe his PCXT dedicated pack will apppear at some point too), but maybe somebody will find it useful too. It worked pretty well when I tested it, albeit a bit slow to boot. But I was using the old core releases, perhaps the new turbo versions have the boot speeds improved.

[spark2k06]

The code before the rebase was saved in the following branch

Notes.
Please set the FDD disk every time after reset. If not, the drive does not seem to recognize it.

https://github.com/kitune-san/PCXT_MiSTer/tree/fdd-work

I have adapted Main and merge your branch with the latest release, however it doesn't seem to work, can you take a look at it in case I missed something at core level?:

https://github.com/MiSTer-devel/PCXT_Mi ... elease-fdd

Below, I also provide the changes made in Main, which are basically a collection and adaptation of the AO486 project for PCXT:

https://github.com/spark2k06/Main_MiSTe ... 4ccdd76de7

I attach the Main and RBF binaries as well.


It's possible that the Main is badly adapted, I'll check it well, but just in case, if you can confirm me that the core merge is correct, we'll move forward

[spark2k06]

I've tried changing the OSD menu text to AO486 and now it passes the diagnostic ROM tests, so the problem is definitely in the Main adaptation, I'll check it out.

However, @kitune-san, the improvements you make, please be from the prerelease branch that would already be ready (for the moment change the text to AO486 for your tests):

https://github.com/MiSTer-devel/PCXT_Mi ... elease-fdd

[spark2k06]

I believe you that the UART flow control signals are connected, but I wonder if they are enabled on the host side. They may default to disabled. One easy check is to see if they toggle using SignalTap.

You were right, only the RX/TX lines seem to be working... now it's time to find out how to activate them. This is the code used for communication with serdrive:

If anyone has any clues...

Code: Select all

	char ComPortBuff[20];
	sprintf(ComPortBuff, "/dev/ttyS1");
	const char* ComPort = NULL;
	ComPort = &ComPortBuff[0];
	...
	serial.Connect(ComPort, baudRate);	
	processRequests(&serial, images[0], images[1], timeoutEnabled, verbose);

Code: Select all

class SerialAccess
{
public:
	void Connect( const char *name, struct baudRate *p_baudRate )
	{
//		char buff1[20], buff2[1024];

		baudRate = p_baudRate;

		pipe = -1;

		if( !access(name, R_OK | W_OK) )
		{
			struct termios state;
			  
			log( 0, "Opening %s (%s baud)", name, baudRate->display );

			pipe = open(name, O_RDWR);
			if( pipe < 0 )
				log( -1, "Could not Open \"%s\"", name );

			tcgetattr(pipe, &state);
			cfmakeraw(&state);
			state.c_cflag |= CRTSCTS | CLOCAL;
			state.c_lflag &= ~ECHO;
			cfsetispeed(&state, baudRate->speed);
			cfsetospeed(&state, baudRate->speed);
			tcsetattr(pipe, TCSAFLUSH, &state);
		}
		else
			log( -1, "Serial port '%s' not found", name );
	}

	void Disconnect()
	{
		if( pipe )
		{
			close( pipe );
			pipe = -1;
		}
	}

	unsigned long readCharacters( void *buff, unsigned long len )
	{
		long readLen;
//		int ret;

		readLen = read(pipe, buff, len);

		if( readLen < 0 )
			log( -1, "read serial failed (error code %i)", errno );

		return( readLen );
	}

	int writeCharacters( void *buff, unsigned long len )
	{
		long writeLen;
//		int ret;

		writeLen = write(pipe, buff, len);

		if( writeLen < 0 )
			log( -1, "write serial failed (error code %i)", errno );

		return( 1 );
	}

	SerialAccess()
	{
		pipe = 0;
		speedEmulation = 0;
		resetConnection = 0;
		baudRate = NULL;
	}

	~SerialAccess()
	{
		Disconnect();
	}

	int speedEmulation;
	int resetConnection;

	struct baudRate *baudRate;

private:
	int pipe;
};

[MicroCoreLabs]

I believe the UART flow control needs to be enabled in the Cyclone-V SOC configuration inside of the HPS. I recall reading that it is disabled by default, and they seems to be what you see.

Actually, is there no activity in either direction? Maybe your core is also not using flow control on your UART.

Once you fix this, you should able to run at megabit speeds on the UART.

[spark2k06]

I believe the UART flow control needs to be enabled in the Cyclone-V SOC configuration inside of the HPS. I recall reading that it is disabled by default, and they seems to be what you see.

Actually, is there no activity in either direction? Maybe your core is also not using flow control on your UART.

Once you fix this, you should able to run at megabit speeds on the UART.

I set a trigger on all signals... and if I did it right, it only detected the level change on RX/TX.

Thanks for the heads up, now it's time to pull the thread and find out how to enable it.

[Caldor]

I made a floppy boot disk for the PCXT core. Its a mix of different things. Sets up a RAM drive, EMS, high mem, 4DOS and Volkov Commander. A clone of Norton Commander that is coded entirely in assembly so its has a very small footprint. Ends up with 610kb mem free.
http://dionysus.dk/devstuff/mister/PCXT ... Floppy.img

[Mills]

Good to see this core released!

Great job!

Is there any equivalent to the eXo/Flynn Top 300 DOS Pack for this core? (focusing on 8086 games)

I don't know if that's a good idea for 8088, I am testing some file managers and they all use ram or install TSR programs that stay in ram and make things slow and glitchy, but maybe it is possible to do it.

[GreyRogue]

I believe the UART flow control needs to be enabled in the Cyclone-V SOC configuration inside of the HPS. I recall reading that it is disabled by default, and they seems to be what you see.

Actually, is there no activity in either direction? Maybe your core is also not using flow control on your UART.

Once you fix this, you should able to run at megabit speeds on the UART.

I set a trigger on all signals... and if I did it right, it only detected the level change on RX/TX.

Thanks for the heads up, now it's time to pull the thread and find out how to enable it.

Haven't read back to figure out what you're trying to do with UART, but if you're having troubles you may not have added it to the config string yet:
https://github.com/MiSTer-devel/Main_Mi ... ion-string
For example:
https://github.com/MiSTer-devel/ao486_M ... 86.sv#L199

[MicroCoreLabs]

Thanks for the heads up, now it's time to pull the thread and find out how to enable it.

If you are not able to enable the hardware flow control then perhaps you could use XON/XOFF which requires no additional flow control signals like CTS/RTS. Each side simply adds a byte to the UART stream to tell the other side to stop and start. Software needs to be aware of these bytes though while it does not need to be aware of the RTS/CTS signals.

[pgimeno]

I don't know if that's a good idea for 8088, I am testing some file managers and they all use ram or install TSR programs that stay in ram and make things slow and glitchy, but maybe it is possible to do it.

The TSR problem can be alleviated by using the TurboPower TSR utils:

http://files.mpoli.fi/software/DOS/UTIL ... RCOM35.ZIP

Description here:

https://www.pcorner.com/list/UTILITY/TSRCOM35.ZIP/INFO/

The basic idea is that you load a TSR called MARK, then load whatever software, and then execute RELEASE /K to get rid of the MARK and (most importantly) any other TSRs loaded after it.

[spark2k06]

If you are not able to enable the hardware flow control then perhaps you could use XON/XOFF which requires no additional flow control signals like CTS/RTS. Each side simply adds a byte to the UART stream to tell the other side to stop and start. Software needs to be aware of these bytes though while it does not need to be aware of the RTS/CTS signals.

Ideally, CTS/RTS should be used so that no additional code needs to be added. But now I have to understand why it doesn't work, in the Linux part I see that it is enabled:

ctrscts.png (10.31 KiB) Viewed 12116 times

I was wrong when I said there was no activity on RTS/CTS, but I am only observing it on RTS and only once during the core reset, then it always stays at 0:

uart_rts_n.png (19.84 KiB) Viewed 12116 times

The trigger is only activated twice, once just at the start of the core (at 1) and once when the recognition of COM devices is about to start (at 0). After that, there is no further change during the read or write.

[spark2k06]

Haven't read back to figure out what you're trying to do with UART, but if you're having troubles you may not have added it to the config string yet:
https://github.com/MiSTer-devel/Main_Mi ... ion-string
For example:
https://github.com/MiSTer-devel/ao486_M ... 86.sv#L199

I have done some tests with this, but the result has always been that serdrive does not work.

[Caldor]

Good to see this core released!

Great job!

Is there any equivalent to the eXo/Flynn Top 300 DOS Pack for this core? (focusing on 8086 games)

I don't know if that's a good idea for 8088, I am testing some file managers and they all use ram or install TSR programs that stay in ram and make things slow and glitchy, but maybe it is possible to do it.

Have you tried just loading it into high ram?

Also:
[Alexey Melnikov 2022-08-25 3570c8b]
Merge pull request #686 from spark2k06/master

Cleanup initialization PCXT

MiSTer Main just accepted the pull request from Spark

[akeley]

I don't know if that's a good idea for 8088, I am testing some file managers and they all use ram or install TSR programs that stay in ram and make things slow and glitchy, but maybe it is possible to do it.

I've used an early version of Norton Commander in my collection, it works rather well. Possibly could be tweaked to be even better. Also flynn/bbond's MyMenu is working. Total DOS Launcher is working too, though its does throw unpacking errors occasionally - but I guess it's not its fault and to be resolved in the future on the packer side (might be related to the problem mentioned in this thread already not long ago).

[Caldor]

I don't know if that's a good idea for 8088, I am testing some file managers and they all use ram or install TSR programs that stay in ram and make things slow and glitchy, but maybe it is possible to do it.

I've used an early version of Norton Commander in my collection, it works rather well. Possibly could be tweaked to be even better. Also flynn/bbond's MyMenu is working. Total DOS Launcher is working too, though its does throw unpacking errors occasionally - but I guess it's not its fault and to be resolved in the future on the packer side (might be related to the problem mentioned in this thread already not long ago).

I can recommend trying Volkov Commander. But I did try Norton Commander 3 in the collection shared that has quite a selection of games. Norton Commander 3 might have some features Volkov Commander lacks, but I like how easy it is to fit Volkov Commander on a floppy disk because I think its less than 200kb. I think it might be possible to use loadhigh on the whole program. I guess another option is to put it on a 512kb RAMdisk. Although I am not sure that makes any difference if it still ends up having to be put into memory.

[darkavengerbr]

First of all, thanks for the great work on this core.
I am trying the core with pre-built hd img files i downloaded.
the question is ( sorry if already answered , but couldnt find) how can I easily tranfer files from my windows pc to an hd img file?
there is an utility for this? I tried 7zip but it only let me read the file and the mounting option in windows gives an error.
Sorry if this too Basic.

Cheers!

[akeley]

the question is ( sorry if already answered , but couldnt find) how can I easily tranfer files from my windows pc to an hd img file?

It's not that straightforward, though I might be missing something. You can use ao486 core on MiSTer plus Dos Navigator or other file manager, and copy from your "normal" vhds (those made for ao486 and mountable in Windows).

Or use PCem emulator on your PC. The PCXT images will work in that. Problem is then you have to make iso CD images with your files from Windows directories, because you can't mount them directly in that emu. Still, that's what I did when moving large amount of files:
-create a Pentium instance in PCem
-use Win98 SE hdd install as C: (there is one ready made on archive.org)
-use the PCXT hdd image as secondary
-mount a premade iso with my files as CDROM
-copy from iso to PCXT hdd using Total Commander

If there's an easier method I'm all ears, as it is a bit of faffing about.

[jordi]

the question is ( sorry if already answered , but couldnt find) how can I easily tranfer files from my windows pc to an hd img file?

It's not that straightforward, though I might be missing something. You can use ao486 core on MiSTer plus Dos Navigator or other file manager, and copy from your "normal" vhds (those made for ao486 and mountable in Windows).

Or use PCem emulator on your PC. The PCXT images will work in that. Problem is then you have to make iso CD images with your files from Windows directories, because you can't mount them directly in that emu. Still, that's what I did when moving large amount of files:
-create a Pentium instance in PCem
-use Win98 SE hdd install as C: (there is one ready made on archive.org)
-use the PCXT hdd image as secondary
-mount a premade iso with my files as CDROM
-copy from iso to PCXT hdd using Total Commander

If there's an easier method I'm all ears, as it is a bit of faffing about.

Just mount in your normal OS the image.

In windows, you'll use Imdisk software.

Linux and Mac, mount or diskutil

[breiztiger]

Osfmount is good also

[ShyTalk]

Hi, I can see you guys are working on a higher level, but, I’m trying to get the core working but I’m struggling with the boot.rom. I’m trying to follow this thread but it’s a fair few IQ points beyond me…. It seems like once upon a time the boot.rom I need to get this running was in the SW folder on github but it doesn’t appear to be there now. Also, it seems you can run a “python script” which i’ve tried but I knew I’d fail to get it working correctly…. my level is more ‘plug console in and turn on’.

Is there any other way of obtaining the boot.rom? For instance, could someone message me with it all? That would be very kind!

Thanks for any help.

Cheers,