PC-98: Graphic LIO not implemented

[hdk1983]

Describe the bug
Graphic LIO is a set of routines in BIOS ROM. I found it was used by the following games/applications:

• KATALITH
• MAZE_999 https://www.vector.co.jp/soft/dos/game/se023680.html
• Microsoft Basic programs that use graphics (probably MAZE_999 is built on Microsoft Basic)

Graphic LIO is in segment F990h. If you see some errors around in segment F990h, probably it is related to this issue. For example:

• KATALITH: ERROR CPU:Write 0 to rom at f9900
• MAZE_999: ERROR CPU:Write 20 to rom at f9900

To Reproduce
Steps to reproduce the behavior:

1. Run a program that uses graphic LIO
2. The program does not start

Expected behavior
The program works

Additional context
To verify the graphic LIO is used, I added a dummy implementation to DOSBox-X as follows:

dummyliopatch.txt

With this patch, KATALITH shows the following copyright screen:

And, MAZE_999 shows the following error (maybe because of the dummy implementation), looks like an error of Microsoft Basic:

I made a hello world program using MSGBOX statement of Visual Basic for DOS:

HELLO2.zip

With the above patch, this program starts with broken graphic screen (maybe because of the dummy implementation):

The hello world works on Neko Project:

[joncampbell123]

Actually, yes, I noticed "Sword of Legend" is quite consistent at jumping to segment F990, evidently without checking properly.

[joncampbell123]

If anyone has a PDF or link to documentation on the LIO interface that would be helpful.

The source code of Neko Project II appears to explicitly implement the LIO interface in bios_lio()

[joncampbell123]

Hm, "Sword of Legend" doesn't seem to really be looking for LIO.

EDIT: It does, it crashed because my initial implementation had a mistake.

EDIT: This is apparently why WINGS also crashed at startup. Now it just sits with a blank screen with debug output indicating that LIO was called.

EDIT: This is also why Balance of Power was crashing. Now it runs, minus many graphics of course.

[hdk1983]

I found Japanese documentation describing the graphic LIO on the web:

• http://chiclassiccomp.org/docs/index.php?dir=%2Fbooks%2FComputing%2FProgramming&highlight=PC-9801Bible_%E6%9D%B1%E4%BA%AC%E7%90%86%E7%A7%91%E5%A4%A7%E5%AD%A6.pdf (Page 184-)
• https://archive.org/details/PC9800TechnicalDataBookBIOS1992/page/n151
• https://archive.org/details/98HardBookBecomingStrongII1988 (Page 181-)

[yksoft1]

Hm, "Sword of Legend" doesn't seem to really be looking for LIO.

EDIT: It does, it crashed because my initial implementation had a mistake.

EDIT: This is apparently why WINGS also crashed at startup. Now it just sits with a blank screen with debug output indicating that LIO was called.

EDIT: This is also why Balance of Power was crashing. Now it runs, minus many graphics of course.

Hell Ogre also require it to work.

[hdk1983]

Fixed by #3508. Thanks.