===== CORE SETUP =====

* I used Mr. Fusion for my SD setup: https://github.com/MiSTer-devel/mr-fusion
    * The root of the SD card contains a _Computer folder. This is where the
    .rbf file for the PC98 core (Zet98) goes.

* The core's author, puu, posts updates to the core on his blog:
http://fpga8801.seesaa.net/ * The cores are posted here as Quartus II .qar
archives. They can be extracted by using https://github.com/makigumo/unqar *
tontonkaloun has also been posting zip versions for download. As of writing, the
latest one is attached to this post:

===== BIOS =====

* If you just want to get going with the core, download tonton.rar attached to
this post: https://misterfpga.org/viewtopic.php?p=18850#p18850
    * Inside is a script named mkrom.sh and a file named Zet98.rom. Ignore the
    script. Rename Zet98.rom to boot.rom. Place into YOUR_SD/games/Zet98.
    Alternatively, place into YOUR_SD/bootrom/Zet98.rom. * The core should boot
    to a black screen. OSD should work via F12. You know it's working if you
    hear some beeps.
Detailed info on the BIOS:

* In puu's post for the first release of the core
(http://fpga8801.seesaa.net/archives/20210107-1.html) he mentions that the core
requires a boot.rom file, which is a catenation of the BIOS, ITF (unsure what
this is), and fonts. These files refer to bios.rom, itf.rom, and font.rom files
which are typically found in PC98 BIOS dumps I've found. Specifically, those are
the files present in the Neo Kobe PC98 archive's BIOS files.
* There has been some discussion on what model PC98 BIOS is required. See:
    * From what I can tell, none of the BIOS included in the Neo Kobe archive are
    appropriate. I tried making the BIOS myself as per the mkrom.sh file with a
    few different models, but to no avail. Whatever BIOS tontonkaloun used to 
    make his Zet98.rom works. I didn't see any mention of specifically what
    model that file was generated from.

For reference, my Neo Kobe archive contains BIOS for the following models:

Epson PC-486HX
Epson PC-486MU
NEC PC-9801 (unknown model)
NEC PC-9801-86 Sound Board
NEC PC-9801UX NEC PC-9821 (unknown model)
NEC PC-9821Ce2
NEC PC-9821V13 NEC
PC-9821V20 YM2608 (OPNA) rhythm samples


According to https://46okumen.com/pachy98/, there's a LOT of disk formats PC98
games can be found in. The only format I care about is .hdm, the format the ROMs
in the Neo Kobe archive are distributed in.

* We need to go from HDM to D88 for this core. Let's take Albion - Domino
Soldier from the Neo Kobe archive as an example. The files are:

Albion - Domino Soldier [FD].zip
    * Albion - Domino Soldier (Disk A).hdm
    * Albion - Domino Soldier (Disk B).hdm
* The [FD] means Floppy Disk. Some games also have an [HD] archive, for Hard
Drive. From reading the thread, it seems people have only had success running
the floppy disk versions of games.
    * wark91 seems to confirm only floppy versions work at the moment:
* To convert the HDM files to D88, I used an ancient piece of software called
Virtual Floppy Image Converter running in a Win2K virtual machine:
    * Open it. Check "EXPORT FOLDER" and provide a path to export the D88 file
    to. set "FORMAT" to "D88 format". Drag the HDM file in the box that says
    "Drag & Drop File(s) Here to Convert"
    * Copy the Albion - Domino Soldier (Disk A).d88 and Albion - Domino Soldier 
    (Disk B).d88 files to YOUR_SD/games/Zet98 or wherever.

A couple side notes:

    * Relying on VFIC seems prone to breaking in the future. Someone rewrote a
    couple conversion tools in Python:
        * We can't go directly from HDM to D88 using these tools. However, going
         from HDM to FDI then using pgimeno's FDI to D88 script
         (http://www.formauri.es/personal/pgimeno/misc/converters.php) might
         work. I haven't tried it. It would be great to have a direct converter
        independent of VFIC.

===== RUNNING GAMES =====

* Boot to the Zet98 core. As mentioned above, if it successfully boots, you'll
get a black screen but hear a few beeps. If you wait long enough DOS(?) will
load, but you don't need to wait.
* Hit F12, go to FDD 0 *.D88 and load Disk A of Albion. Do the same for FDD1 and
Disk B.
* Hit Reset.
* Wait for a while, it takes a moment to boot. Some text from DOS will show up
after a while and continue booting the game.


* Some games (Rusty) will display a message telling you to flip DIP switch 2-8
to 2.5MHz in order to run. In that case, hit F12 and scroll to the bottom to
toggle it. Additionally, some games will look visually messed up
(duplicated/misaligned image) but WILL NOT provide the warning Rusty does. The
fix is the same: switch to 2.5MHz.
* In general, having the DIP switches set to what puu recommends is probably a
good idea:

DIP1-8 Extend
DIP1-3 Normal
DIP2-1 1
DIP2-2 Basic
DIP2-3 80
DIP2-4 25
DIP2-5 Keep
DIP2-6 Connect
DIP2-7 Control
DIP2-8 2.5MHz

===== OTHER NOTES =====

* On my PVM (supports up to 1080i), I'm unable to get a good image unless
vga_scaler is set to 1. I don't know why this is, as supposedly the PC98 runs at
640x400. Without this on, some games display only a dark green color, and in
general the brightness seems to be screwed up. With the VGA scaler on they look
fine... unfortunately, without scanlines!