MiSTer PCXT

[suww37]

What kind of effort should I do to solve this? I'd like to see the 15khz crt screen.

I did not try it with the PCXT core, but in general my PVM requires the INI file to have composite_sync=1 to work well.
Maybe check if you have that on? If not, worth a try

Unfortunately, if I do that, I will encounter a weirder screen.

[wark91]

What kind of effort should I do to solve this? I'd like to see the 15khz crt screen.

I did not try it with the PCXT core, but in general my PVM requires the INI file to have composite_sync=1 to work well.
Maybe check if you have that on? If not, worth a try

Unfortunately, if I do that, I will encounter a weirder screen.

Could you please share your mister.ini file to see if there is some configuration to adapt ?

[suww37]

I did not try it with the PCXT core, but in general my PVM requires the INI file to have composite_sync=1 to work well.
Maybe check if you have that on? If not, worth a try

Unfortunately, if I do that, I will encounter a weirder screen.

Could you please share your mister.ini file to see if there is some configuration to adapt ?

[wark91]

Thank you !

In your file, you have two things seems not good.

first point : "volumectl=1" not sure it is use. It is not present in default ini file. Do you know why this option is here ?

Second point:

; Set to 1 for automatic HDMI VSync rate adjust to match original VSync.
; Set to 2 for low latency mode (single buffer).
; This option makes video butter smooth like on original emulated system.
; Adjusting is done by changing pixel clock. Not every display supports variable pixel clock.
; For proper adjusting and to reduce possible out of range pixel clock, use 60Hz HDMI video
; modes as a base even for 50Hz systems.
vsync_adjust=1 Match display frequency

Match display frequency highlighted is not good it is need to be commented by adding ";" before the texte.
you could try to set "vsync_adjust=0" to see if it helps.

Third point : you set vga_scaler to 1. Normally with your screen at 15Khz you don't need to pass by the scaler. You could try set it to 0 to see.
If one core required to pass by vga_scaler you can set specifically for this core by putting this option under [NAME_CORE] to apply it just for the core you want to pass by the scaler.

[breiztiger]

Volumectl=1 is for keyboard that have multimédia keys (vol +, vol -, mute)

Édit: volumectl=0 ; enable audio volume control by multimedia keys

[suww37]

Thank you !

In your file, you have two things seems not good.

first point : "volumectl=1" not sure it is use. It is not present in default ini file. Do you know why this option is here ?

Second point:

; Set to 1 for automatic HDMI VSync rate adjust to match original VSync.
; Set to 2 for low latency mode (single buffer).
; This option makes video butter smooth like on original emulated system.
; Adjusting is done by changing pixel clock. Not every display supports variable pixel clock.
; For proper adjusting and to reduce possible out of range pixel clock, use 60Hz HDMI video
; modes as a base even for 50Hz systems.
vsync_adjust=1 Match display frequency

Match display frequency highlighted is not good it is need to be commented by adding ";" before the texte.
you could try to set "vsync_adjust=0" to see if it helps.

Third point : you set vga_scaler to 1. Normally with your screen at 15Khz you don't need to pass by the scaler. You could try set it to 0 to see.
If one core required to pass by vga_scaler you can set specifically for this core by putting this option under [NAME_CORE] to apply it just for the core you want to pass by the scaler.

Thank you for helping me first. But even if I do what you say, the symptoms are the same. It doesn't seem to be a problem with the MISTER.ini setting.

[wark91]

Volumectl=1 is for keyboard that have multimédia keys (vol +, vol -, mute)

Thanks. I didn't know this option !
and it is not present in this sample file : https://github.com/MiSTer-devel/Main_Mi ... MiSTer.ini

[suww37]

Thanks. That tells me its not the resolution but something else. Maybe a sync issue. I don't yet fully understand how the core is handling video, but there is something non standard going on.

Is it a sync problem? However, in other people's crt, 15khz is output normally, so I don't understand why I'm the only one who can't output it. Do you think there is a problem with the pcxt core? What kind of effort should I do to solve this? I'd like to see the 15khz crt screen.

Some CRTs are able to handle an off specification sync signal much better than others. In my experience so far on this project, it's normal for cores to have wonky video this early on. It's an early beta and you should just deal with it for now.

When I run with Tandy, the top of the screen is a little crushed, but it's still worth watching. However, the cga is crushed a lot.

[wark91]

Thank you !

In your file, you have two things seems not good.

first point : "volumectl=1" not sure it is use. It is not present in default ini file. Do you know why this option is here ?

Second point:

; Set to 1 for automatic HDMI VSync rate adjust to match original VSync.
; Set to 2 for low latency mode (single buffer).
; This option makes video butter smooth like on original emulated system.
; Adjusting is done by changing pixel clock. Not every display supports variable pixel clock.
; For proper adjusting and to reduce possible out of range pixel clock, use 60Hz HDMI video
; modes as a base even for 50Hz systems.
vsync_adjust=1 Match display frequency

Match display frequency highlighted is not good it is need to be commented by adding ";" before the texte.
you could try to set "vsync_adjust=0" to see if it helps.

Third point : you set vga_scaler to 1. Normally with your screen at 15Khz you don't need to pass by the scaler. You could try set it to 0 to see.
If one core required to pass by vga_scaler you can set specifically for this core by putting this option under [NAME_CORE] to apply it just for the core you want to pass by the scaler.

Thank you for helping me first. But even if I do what you say, the symptoms are the same. It doesn't seem to be a problem with the MISTER.ini setting.

Hope next updates could sort your issue.
last test (just in case) try the default ini file https://raw.githubusercontent.com/MiSTe ... MiSTer.ini and set just direct_video to 1.

[Malor]

That bent screen looks like the output timing might not be stable at the start of a frame, like maybe something is ringing a bit until it settles.

edit: well, ringing might be a poor word choice... it looks like, starting about 8 lines down, the video signal is arriving early, and then stabilizes later.

[suww37]

Why is there a line under TEXT in pcxt core tandy bios?

[Newsdee]

Why is there a line under TEXT in pcxt core tandy bios?

See here for a fix for now:
viewtopic.php?p=56151#p56151

There are quite a few things in the core not finalized in terms of signal timings. This is why you see this and the PVM issue. Fixing those is not easy but as the core matures they will improve.

To give you an idea, you can have a look at how VGA works:
http://javiervalcarce.eu/html/vga-signa ... cs-en.html

15khz video is less standard but similar principles apply

[suww37]

Why is there a line under TEXT in pcxt core tandy bios?

See here for a fix for now:
viewtopic.php?p=56151#p56151

There are quite a few things in the core not finalized in terms of signal timings. This is why you see this and the PVM issue. Fixing those is not easy but as the core matures they will improve.

To give you an idea, you can have a look at how VGA works:
http://javiervalcarce.eu/html/vga-signa ... cs-en.html

15khz video is less standard but similar principles apply

I didn't understand. Will it be a normal screen if I use MS dos 3.2?

[Newsdee]

I didn't understand. Will it be a normal screen if I use MS dos 3.2?

There is a DOS 3.2 command to switch video output to 200 lines

[suww37]

Right keypad * key, + key, - key can not be inputed

[spark2k06]

I have made a work around to the problem of ghost lines in text mode, thanks @Mills for giving me the hint:

https://github.com/spark2k06/PCXT_MiSTe ... 130a6fcb20

If you examine the commit, you will see that I intercept the change of v_maxscan when tandy and text modes are enabled. If requested to change to 8 (225 lines, 9 per character), I force it to be 7... i.e. we are back to 200 lines and nothing happened

However, this is not the best solution, so we will consider it temporary, in order not to have to use MODE 200, and to make life easier for core users.

I have located the real problem of the ghost line in text mode of the Tandy BIOS, it is in cga_pixel.sv:

cga_pixel.png (30.11 KiB) Viewed 7708 times

The character font is 8x8, however, with the change to 225 lines it should be 8x9... and the last row should be an empty line, however what is happening is that the line reading is looped and so the first row is repeated (which would be the ghost line), it seems that the solution to this is simple, but I can't see how to fix it, so for the moment we'll stick with the work around.


I attach the updated prebeta 1.5, but a warning regarding the turbo version, and is that apparently, this change has made the memory unstable ... no idea why, I attach it also as a curiosity, but I recommend to continue using PCXT_PREBETA_1_5_TURBO_04 instead of this if the 05 gives you problems, which will give you problems.

[pgimeno]

I don't know how a CGA behaves if the selected character height is greater than 8, if that is possible at all. Does anyone know? Is there anyone who has a functional PC with CGA and is willing to test?

Depending on the answer, a patch for the ghost line problem should be Tandy-specific or general.

Also, can someone with a Tandy machine confirm if there are blank lines when displaying a screen full of solid blocks? I suspect that instead of adding a blank line, it repeats the last line.

The fix might be as simple as:

Code: Select all

assign rom_addr = {char_byte, (row_addr < 5'd8 ? row_addr[2:0] : 3'd7)};

(in place of https://github.com/spark2k06/PCXT_MiSTe ... el.sv#L120)

[spark2k06]

I don't know how a CGA behaves if the selected character height is greater than 8, if that is possible at all. Does anyone know? Is there anyone who has a functional PC with CGA and is willing to test?

Depending on the answer, a patch for the ghost line problem should be Tandy-specific or general.

Also, can someone with a Tandy machine confirm if there are blank lines when displaying a screen full of solid blocks? I suspect that instead of adding a blank line, it repeats the last line.

The fix might be as simple as:

Code: Select all

assign rom_addr = {char_byte, (row_addr < 5'd8 ? row_addr[2:0] : 3'd7)};

(in place of https://github.com/spark2k06/PCXT_MiSTe ... el.sv#L120)

Very well seen. Great contribution!

620_225_ok.jpg (91.63 KiB) Viewed 7611 times

I'll update the repository as soon as I can and re-submit the binaries.

Thanks for your help!

[pgimeno]

Here's a test program to check the behaviour of 9 lines per character. It prints two lines of checkerboard block characters in order to see what happens in a CGA and in a Tandy.

[spark2k06]

Here's a test program to check the behaviour of 9 lines per character. It prints two lines of checkerboard block characters in order to see what happens in a CGA and in a Tandy.

I have tried your application, and another one developed by @Mills, and finally I have left one line blank and conditioned to be in Tandy mode:

https://github.com/spark2k06/PCXT_MiSTe ... c1ba077ed4

All this, derived from the tests I have carried out on PCem with CGA and with Tandy, would have to be confirmed on real hardware but for the moment that is the way it is. I attach binaries, again the turbo version is now unstable because of this small code change.

[suww37]

Here's a test program to check the behaviour of 9 lines per character. It prints two lines of checkerboard block characters in order to see what happens in a CGA and in a Tandy.

I have tried your application, and another one developed by @Mills, and finally I have left one line blank and conditioned to be in Tandy mode:

https://github.com/spark2k06/PCXT_MiSTe ... c1ba077ed4

All this, derived from the tests I have carried out on PCem with CGA and with Tandy, would have to be confirmed on real hardware but for the moment that is the way it is. I attach binaries, again the turbo version is now unstable because of this small code change.

The turbo core freezes during boot.

[spark2k06]

Here's a test program to check the behaviour of 9 lines per character. It prints two lines of checkerboard block characters in order to see what happens in a CGA and in a Tandy.

I have tried your application, and another one developed by @Mills, and finally I have left one line blank and conditioned to be in Tandy mode:

https://github.com/spark2k06/PCXT_MiSTe ... c1ba077ed4

All this, derived from the tests I have carried out on PCem with CGA and with Tandy, would have to be confirmed on real hardware but for the moment that is the way it is. I attach binaries, again the turbo version is now unstable because of this small code change.

The turbo core freezes during boot.

" again the turbo version is now unstable because of this small code change"

[akeley]

1. create the disk using serdrive
2. make sure the disk has a vhd extension and move it to your AO486 directory
3. have a primary disk mounted to 0-0 that has fdisk, a dos system of your choosing, and format commands.
4. you can also use an installer like MS-DOS 6.22 from the floppy and in that case you would mount the vhd you created to 0-0 (make sure and set the floppy to boot in the AO486 hardware menu option or it wont ever boot the floppy install)
5. boot the system (from floppy or a pre-configured DOS VHD in 0-0), you should land at dos
6. run fdisk. select the appropriate disk, then select option 1 to create a partition
7. reboot
8. back to dos format d: (if this is your second disk) or format c: if you booted with a floppy and it is your primary disk 0-0
9. if you are trying to use any of my pre-built images for the boot drive, you need to run "assign" with no options to temporarily remove the D: mapping I have in the autoexec which takes over the D: drive.
10. copy the DOS directory over to you newly formatted drive and anything else you want.
11. set the pcxt_hdd_mount.sh script to mount the drive you just created (good time to increase the transfer speed to 460K in the script if you havent), and put yours in the location it expects /games/PCXT/hdd.img
12. Run the script
13. Run the core.

I've tried this on a hdd image made with "./serdrive -n 500MB 500.img". I did the fdisk, format, then installed DOS 6.22 via native setup installer (from floppies). It boots fine in ao486, but when I move it to the PCXT, I get "Invalid partition table" error (after "Booting C>>C").

Running Prebeta 1.5.06 and latest uart script - this handles my older (small) images ok. Any ideas why it might be happening?

EDIT: all good now, thanks to flynnsbit's help.

[spark2k06]

I've started with the preliminary development of what will be the prebeta 2.0 version, we won't need the image mount script anymore

prebeta_2.0.jpg (71.97 KiB) Viewed 7212 times

On this occasion, the MiSTer file needs to be updated.

For the time being, the configuration is not saved, nor is the image specified in the menu displayed, but the assembly takes place, and after a reset, you can see that it starts. In addition, the image is currently mounted at a fixed speed of 460.8K and must comply with the following parameters:

Code: Select all

cyl = 62;
sect = 63;
head = 16;

It is also not possible to unmount the image, and I don't know what effect the image change will have if you haven't restarted MiSTer, it is a very preliminary version.

[suww37]

What is " MiSTer_PCXT.zip" and where do I put it?

[wark91]

What is " MiSTer_PCXT.zip" and where do I put it?

It is not easy.
It is the mister main and it is located the /main/fat directory on your sdcard.
If you update your mister this action needs to be done again because the last release of Main Mister will replace it.
I think it is better to wait for this point.

[Newsdee]

Is it possible to support mouse with this setup? Or is the serial port completely taken over by the serial disk?

[suww37]

What is " MiSTer_PCXT.zip" and where do I put it?

It is not easy.
It is the mister main and it is located the /main/fat directory on your sdcard.
If you update your mister this action needs to be done again because the last release of Main Mister will replace it.
I think it is better to wait for this point.

I copied the PCXT file using SAMBA to the /main/fat directory, but it can't be copied.

It is said that the copy is unloaded because it is being used by MiSTer.

How can I copy it?

[wark91]

What is " MiSTer_PCXT.zip" and where do I put it?

It is not easy.
It is the mister main and it is located the /main/fat directory on your sdcard.
If you update your mister this action needs to be done again because the last release of Main Mister will replace it.
I think it is better to wait for this point.

I copied the PCXT file using SAMBA to the /main/fat directory, but it can't be copied.

It is said that the copy is unloaded because it is being used by MiSTer.

How can I copy it?

You need to remove the one on the SDCard.

[flynnsbit]

I've started with the preliminary development of what will be the prebeta 2.0 version, we won't need the image mount script anymore

prebeta_2.0.jpg

On this occasion, the MiSTer file needs to be updated.

For the time being, the configuration is not saved, nor is the image specified in the menu displayed, but the assembly takes place, and after a reset, you can see that it starts. In addition, the image is currently mounted at a fixed speed of 460.8K and must comply with the following parameters:

Code: Select all

cyl = 62;
sect = 63;
head = 16;

It is also not possible to unmount the image, and I don't know what effect the image change will have if you haven't restarted MiSTer, it is a very preliminary version.

One small request. Could you also add the second *.IMG file option so we can mount a floppy to A. For serdrive it is just simply passing in a second file on the serdrive path, it needs to be at the very end of the serdrive command. I realize we will have to bounce it when swapping out floppy disks but it would be nice to mount one for now.

Code: Select all

Floppy images may also be used.  Image size must be exactly the same size
as a 2.88MB, 1.44MB, 1.2MB, 720KB, 360KB, 320KB, 180KB, or 160KB disk.
Floppy images must be the last disks discovered by the BIOS, and only
two floppy drives are supported by the BIOS at a time.

Also one cool byproduct of you starting with serdrive is now in the future, you could add options in the core menu for creating different image disks, including floppy disks directly from inside the core. That would allow everything to be self contained without having to leave the core to create new disks, floppy images, etc for mounting. Even when actual IDE/Floppy controller support is added this would be a really cool feature.