MiSTer PCXT

[spark2k06]

Thank you . Now I think the most important thing left is mouse support.

I'm not sure that's possible as long as we have /dev/ttyS1 in use for serdrive.

Besides, I'm not done with Main yet. There are some fixes to be done, some read-only support, removing dependency on the CHS specification by using a predefined CHS table like the one in PCEm, and then a good refactoring of the code to stay in Main until we have IDE.

[spark2k06]

New Main:

• HDD CHS Calculator

You no longer have to specify the CHS in MiSTer.ini, it is automatically calculated based on the image size and PCEm CHS table. Ideally, create new images using the tool provided by this emulator:

https://github.com/spark2k06/Main_MiSTe ... 2fe96f5302

PCEm_HDD_Create.png (25.03 KiB) Viewed 10095 times

Furthermore, it is possible to hot-swap floppy disk images, so that the operating system can be installed from scratch without any problem.

[NML32]

New Main:

• HDD CHS Calculator

You no longer have to specify the CHS in MiSTer.ini, it is automatically calculated based on the image size and PCEm CHS table. Ideally, create new images using the tool provided by this emulator:

https://github.com/spark2k06/Main_MiSTe ... 2fe96f5302

PCEm_HDD_Create.png

Furthermore, it is possible to hot-swap floppy disk images, so that the operating system can be installed from scratch without any problem.

I'm having an issue mounting my HDD image with the new Main_Mister unless I mount a FDD and HDD.

I must mount both HDD and FDD, or neither Master nor Slave COM is detected.

[spark2k06]

I'm having an issue mounting my HDD image with the new Main_Mister unless I mount a FDD and HDD.

I must mount both HDD and FDD, or neither Master nor Slave COM is detected.

I have seen why it happens. I'll fix it for the next revision.

[somhi]

For anyone wanting to develop on PCXT core, I just show you how compiling times differ in my system (i5 old laptop):
For MiSTer framework, it takes 18:29 minutes.
For Non-Mister (cyclone IV) it takes 7:46 minutes.

[kitune-san]

I have created a new turbo mod. Several unstable behaviors (especially at 4.77 MHz) have been improved.
Please rebase this branch if you want to use turbo mode in future releases.

https://github.com/kitune-san/PCXT_MiST ... -new-turbo

[spark2k06]

I have created a new turbo mod. Several unstable behaviors (especially at 4.77 MHz) have been improved.
Please rebase this branch if you want to use turbo mode in future releases.

https://github.com/kitune-san/PCXT_MiST ... -new-turbo

It works incredibly well! I'm in the middle of several changes to the MiSTer Main to support write protection on FDD and HDD, and I'm also going to integrate serdrive speed selection from the OSD, but I'm glad to know that now we can finally have a single branch that unifies all speeds

[kitune-san]

The 4.77 MHz clock is running slower in this turbo mod branch than in prebeta-2.0.
I will make a fix for this.

[spark2k06]

New updates:

PREBETA 2.0.05

• Reworking of the OSD menu
• Modified CPU core to operate in turbo mode, by kitune-san
• Improved access timing to peripherals, by kitune-san
• Improved access speed to SDRAM, by kitune-san

Thanks to the latest @kitune-san updates, it is no longer necessary to maintain several branches.

MAIN 2.0.05

• Win+F12 for OSD
• Getting ROM according to model
• UART speed variable
• FDD & HDD Write protected feature
• Fix umounting images
• Fix CHS Calculator

Initially, the UART speed will be set to 115.2Kb, curiously this speed does not work very well. I suggest using the rest, mainly 460.8Kb, but if the core runs at 14.318MHz, it is also possible to use 921.6Kb!!!!

I also attach some tools to obtain ROMs from PCXT and Tandy.

In the games/PCXT folder, the files pcxt.rom and tandy.rom should now exist.

[wark91]

Thank you for the update.
I think it will be great to keep option on the OSD to load BIOS or XTIDE.

[spark2k06]

Thank you for the update.
I think it will be great to keep option on the OSD to load BIOS or XTIDE.

The fact is that now the core reset is linked to the selected model, which automatically loads the appropriate ROM. To keep the option to load ROM and XTIDE, I should adapt it to ignore the PC model during the reset... via some developer option, because that's really what it is.

I will keep this in mind for future revisions.

[wark91]

thanks !

[spark2k06]

Theoretically, and this is why the server supports it, 921.6K should be possible with a fast enough card and an 8x multiplier, hosted in a computer that can operate at least twice as fast as a 4.77Mhz 8088 machine. I have only tested up to 460.8K with actual hardware.

https://www.xtideuniversalbios.org/wiki/SerialDrives

Using 921.6Kbps as the serdrive speed is only possible with the 14.318Mhz core, and can be very useful for installing the OS from scratch on the same core, or simply using the 14.318Mhz core:

Boot_at_921_6KBps.jpg (102.71 KiB) Viewed 9583 times

The transfer rate is comparable to an HDD on a real PCXT at 4.77Mhz:

HDDSpeed_as_PCXT.jpg (106.35 KiB) Viewed 9583 times

[spark2k06]

Now it is time to review and refactor the changes in Main to try to bring it into the official Main:

https://github.com/spark2k06/Main_MiSTe ... t_serdrive

[kitune-san]

The 4.77 MHz clock is running slower in this turbo mod branch than in prebeta-2.0.
I will make a fix for this.

Modified.
https://github.com/kitune-san/PCXT_MiST ... -turbo-fix

[spark2k06]

New updates:

PREBETA 2.0.06

• Modified to switch data sampling timing between Turbo mode and Normal mode, by kitune-san
• Switch the CPU clock at the timing of biu_done=1'b1, by kitune-san
• Fix CGA memory mapper

[spark2k06]

New updates:

MAIN 2.0.06

• Fix Win+F12 for OSD
• Fix unmounting CHS
• Remove warnings
• Up to date with MiSTer-devel/Main_MiSTer:master

https://github.com/spark2k06/Main_MiSTe ... t_serdrive

[AmintaMister]

Hi all!

I've watched yesterday a video of The 8 Bit Guy that explains how and why CGA 4 colors looked like 16 colors in composite: https://www.youtube.com/watch?v=niKblgZupOc.

So today I've used the PCXT core via composite output but I didn't get the 16 colors, maybe it has to be implemented by code in the core?

[dmckean]

Hi all!

I've watched yesterday a video of The 8 Bit Guy that explains how and why CGA 4 colors looked like 16 colors in composite: https://www.youtube.com/watch?v=niKblgZupOc.

So today I've used the PCXT core via composite output but I didn't get the 16 colors, maybe it has to be implemented by code in the core?

Yes that is something that would need to be implemented.

[spark2k06]

In my experience, 921.6Kbps can be unstable even at 14.318Mhz. I recommend keeping it at 460.8Kbps.

[thorr]

Any word from the person who said they would help with implementing an IDE controller? How does something like that actually work? Does the core have ISA slots with pins that can be wired into? I always wondered about that. To me, with having the schematic available for a working IDE controller, this seems like it should be fairly trivial to implement. I have no experience with developing MiSTer cores, so I am only guessing based on my EE knowledge.

[thorr]

Hi all!

I've watched yesterday a video of The 8 Bit Guy that explains how and why CGA 4 colors looked like 16 colors in composite: https://www.youtube.com/watch?v=niKblgZupOc.

So today I've used the PCXT core via composite output but I didn't get the 16 colors, maybe it has to be implemented by code in the core?

My mind is blown. I had no idea that CGA was capable of doing that. I remember the composite output on the CGA card, but I don't think I ever hooked it up before. I always used RGBi mode. After seeing that video, it would be very cool if PCXT could emulate composite mode, or alternatively, if displaying on a TV using component output out of the MiSTer would achieve the same effect. Theoretically, I would think it should just work on a TV without coding anything special for it if it is displaying accurately. I have an Apple IIc composite monitor. I will have to look into the best way to get composite out of the MiSTer and try it.

[dmckean]

A Y/C version of the core would need to be created to get those effects. CGA uses a pixel clock of nearly 21 Mhz to achieve such precise color artifacting over composite.

[thorr]

A Y/C version of the core would need to be created to get those effects. CGA uses a pixel clock of nearly 21 Mhz to achieve such precise color artifacting over composite.

Thanks! I just found the other thread where a bunch of cores are being converted for composite. After writing my above post, I was contacted by Mouser that my second MiSTer is finally shipping, and I already have the Antonio Villena addons for it, minus the composite adapter. I read in the other thread that he is going to make a new version of the composite adapter. I am not sure if I should wait for that or try to do something else on my own. This is all new to me. Hopefully someday PCXT will have a Y/C version. Based on that video above, it would be well worth it for these old games.

[spark2k06]

@MicroCoreLabs, I want to try to investigate why the DOSMAX driver crashes on this core, but first, I would like to make sure that it has nothing to do with MCL86. The configuration of the CONFIG.SYS file I have is as follows:

Code: Select all

FILES=30
DOS=HIGH,UMB
DEVICE=C:\USE!UMB.SYS D000-E000
DEVICE=C:\DOSMAX\DOSMAX.EXE /R+ /N+ /P-
SHELL=C:\DOSMAX\SHELLMAX.COM C:\COMMAND.COM C:\ /E:256 /P

The crash occurs on line 4. Can you confirm that this problem does not occur on a real PC with MCL86?

DOSMAX, together with USE!UMB.SYS, can be downloaded from here:

https://github.com/monotech/NuXT/blob/m ... DOSMAX.zip

[spark2k06]

BETA 2.0 soon available in the official MiSTer repository:

https://github.com/spark2k06/PCXT_MiSTe ... a693e62489

• Fix CGA memory mapper.
• Switch the CPU clock at the timing of biu_done=1'b1.
• Modified to switch data sampling timing between Turbo mode and Normal…
• Modified CPU core to operate in turbo mode.
• Improved access timing to peripherals.
• Improved access speed to SDRAM.
• Memory map selection according to video mode
• Fix READY signals.
• Setting timings for tandy_16_gfx mode.
• Overscan removal.
• changed chipset clock to 50 mhz and rework.
• OSD menu update to accept HDD and FDD images.
• Added HQ2X and Gamma support.
• Add MiSTer Filters support (updated to latest framework)

The new prebeta branch would be available here:

https://github.com/spark2k06/PCXT_MiSTe ... rebeta-2.1

[wark91]

Thank you for the great update !
To open the OSD (WIN+F12), on the shell when I click on WIN key I have a lot of "^^^^" on the console.
Do you think it will possible to not permit this key "WIN" to interact with the core ?

Edit: This behavior is just on Tandy Mode.

[breiztiger]

hi
with last build and last mister main, i block at splatch screen
i have reset setting the same

[wark91]

@breiztiger, now the core seach for a pcxt.rom or tandy.rom to pass the splashscreen.
You have a roms.zip on previous comment to build those roms

[breiztiger]

Ah ok thanks a lot