SONY MSX2 based Titler XV-T550 mod and PAL mode problem.

Door flyingharuka

Supporter (7)

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15-08-2019, 16:20

hi im chinese MSX fans. this is my first topic.

I have an XV-T550. I saw the topic of NYYRIKKI, but I couldn't find a proper way to use the keyboard.

So I started to modify the MSX myself. I want to modify it into a pure MSX2 gaming console ,

First I removed the sub-ROM.and installed a socket, the titler software was burn-in this chip.

Then I looked at the service manual and found that CN506 Pin2 in the analog video board could be cut off, so that MSXLOGO could be displayed.

However, now there is a problem that the screen cannot be displayed properly.
I guess it is displayed in 60HZ mode under MSX BASIC. How can i solve this problem?

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Van sdsnatcher73

Prophet (2335)

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15-08-2019, 16:58

I don’t think I can help you with your issue other that saying 你好,欢迎光临!

Van hamlet

Scribe (3732)

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15-08-2019, 17:00

Welcome flyingharuka. Nice to meet a Chinese user here!

Van Pentarou

Champion (400)

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15-08-2019, 18:49

You want to change video mode to NTSC or PAL?
I can see a Carnivore2 in the 2nd photo, the cart has a built-in video mode changer and you only need a Joystick to make the selection.

Van flyingharuka

Supporter (7)

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15-08-2019, 19:25

yeah thatis my diy c2 cart, but i want to be fixed the video mode.

If the display can be stabilized, I think NTSC or PAL is both all right.

Van Pentarou

Champion (400)

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15-08-2019, 19:35

What kind of display are you using? Is it capable of both NTSC/PAL?

Van flyingharuka

Supporter (7)

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15-08-2019, 20:28

Pentarou wrote:

What kind of display are you using? Is it capable of both NTSC/PAL?

yeah, in fact, many TV sets in China can support both NTSC/PAL formats, even some TV can both PAL, NTSC and SCEAM.

I want to get different modification ways, because I can buy a lot of titler. They are a very old stock.

itsays :" sony XV-T550 machine and keyboard & mouse , function ok , no cancel no return"

I bidded one of them and decided to modify it to a usable MSX2 compatible.

edit:

I guess need to modify the analog board if I want to transform video mode to NTSC. Then I may need to refer to the XV-J550 -- the Japanese version of analog board , I need here friends to help to find their differences. or how to modify to NTSC,

If I want to change to PAL, maybe make some changes to BIOS ROM.
BTW:
omg, the service manual is tooooo bad that I can't see what's marked on it.

Van NYYRIKKI

Enlighted (5889)

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16-08-2019, 01:56

flyingharuka wrote:

hi im chinese MSX fans. this is my first topic.

Hi, and welcome!

Quote:

I have an XV-T550. I saw the topic of NYYRIKKI, but I couldn't find a proper way to use the keyboard.

Yes, that is a bit tricky one... Part of the keyboard lines are connected to the controller, but rest of the keyboard lines are available only in MSX-Engine where they are pretty hard to jump wire to any proper MSX keyboard... I "solved" the issue by connecting old PS/2 keyboard to "mouse port" (Joystick port 1) and then I wrote little TSR program to use it... This kind of solution was fine enough for running DOS applications, writing BASIC programs and running my favorite debugging environment, but it can't really be used for gaming purposes... There exists some PS/2 keyboard interface cartridges (at lest from Leonardo Padial) as well and I expect them to work better than software solution, but I guess they are pretty hard to find.

Quote:

So I started to modify the MSX myself. I want to modify it into a pure MSX2 gaming console

Here I took quite different approach.. I also wanted to play games on it, but I didn't do any modifications to the device it self... It seems to be quite good, but I noticed some minor hickups. Notably one of my favourite shoot em ups; "Pleasure Hearts" had some minor graphics corruptions here and there during game play... I guess this is because of the genlocker...

Quote:

However, now there is a problem that the screen cannot be displayed properly.
I guess it is displayed in 60HZ mode under MSX BASIC. How can i solve this problem?

Yes, I noticed this as well... The BIOS is Japanese, so it boots to 60Hz, but I think this device can't sync to 60Hz because of the genlock hardware is fixed to 50Hz. Although genlocker causes these kind of problems, I still kind of like it... Playing ie. Nemesis on top of some TV space document is quite psychedelic experience. Tongue

If you ask me, I would keep this as PAL 50Hz device rather than starting to modify the analog part, but then you have to select some way to boot it to 50Hz mode instead. Here are some ideas how you can do that:

- If your CF interface boots to BASIC, write "10 VDP(10)=2" and save the program with name AUTOEXEC.BAS ... This way the output will change to 50Hz when BASIC starts.
- If your CF interface boots to DOS then you need to add 50HZ.COM (*) to your AUTOEXEC.BAT
- If you have some custom made ROM in the machine or you can ie. flash your CF interface, you can patch the functionality to there as well. (I used this method) I can help if needed.
- Desolder the Japanese BIOS and burn European version to ROM instead.

(*) How to get 50HZ.COM ??? -> Execute this BASIC program:

10 DEFINTA-Z:DIMD(7):FORI=0TO7:READD(I):NEXT
20 FORI=0TO2:IFITHENN$=OCT$(32+I*8):READD(2)
30 COPYDTON$+"Hz.COM":NEXT
40 DATA-6111,32511,750,-3209,-26157,-30402,-26157,201,758,-538

... This will make you 3 little programs:
- HZ.COM will toggle between 50Hz/60Hz when executed
- 50HZ.COM will force the display to 50Hz (that is what you need)
- 60HZ.COM will force the display to 60Hz mode.

Van lintweaker

Champion (417)

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16-08-2019, 07:42

Very nice! I am with NYYRIKKI to not do hw modifications, leave it at PAL.
I still have a unit around waiting for me to make it a proper MSX2 as well. I'll keep an eye on this thread.

Van flyingharuka

Supporter (7)

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17-08-2019, 11:57

Thanks a million for your reply ,NYYRIKKI.
I have started to replace an EPROM.

Last night, I combined the BIOS of NMS8250 according to the structure of XVT550
(0-7fffh = mainrom, 8000-bfffh = diskrom, c000-ffffh = extrom or I misremembered)

If I had time to do it, I would write about some new progress.

Van igal

Master (216)

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28-08-2021, 16:18

Hi. (sorry for my very bad English)

I don't know if it's work on the XV-T550..

On Philips NMS8280 (Superimpose, genlock), if you change the original VDP9938 (Msx2) for an VDP9958 (Msx2+), you need to fixe a video synchronous problème by an hardware modification specific.
The symptomatic problem it's like a [60hz video signal] on a [50hz monitor].

After a long research and very big chance, I find a very simple software solution for fixe the "turn around image".

For more informations => http://msxvillage.fr/forum/topic.php?id=1866&pt=1

Sorry, it' s in French :)
Il faut dissocier trois problèmes qui sont peut être liés mais dont je ne saurais expliquer la cause mais simplement trouvé la solution.

Premier problème résolu:
1) Le fait de basculer le 8280 par SET VIDEO 2,X,X (avec la présence d'une source vidéo Externe 50Hz) désynchronise l'affichage de MSX. La "stabilisation" de l'affichage du MSX est rétabli par SCREEN X,,,,,3.
Nb: La boucle sur SET VIDEO 2,X,X sert seulement maintenir le BUG jusqu'à ce que l'écran soit correctement cadré.

Second problème résolu:
2) Le fait de Basculer le 8280 pas SET VIDEO 2,X,X (avec la présence d'une source vidéo Externe 60Hz) désynchronise l'affichage de MSX. Pour rétablir la syncrhonisation avec la source vidéo externe, il faut commencer par basculer le VDP en 60Hz avec VDP(10)=4.
Après quoi, il faut procéder à SCREEN X,,,,,3.
Nb: La boucle sur SET VIDEO 2,X,X sert seulement maintenir le BUG jusqu'à ce que l'écran soit correctement cadré.

Troisième problème résolu:
3) Brancher un 8250 / 55 / 80 sur un LCD, l'image vibre terriblement. Les commandes VDP(10)=3:VDP(10)=2 permettent de solutionner ce problème.
Nb: VDP(10)=3:VDP(10)=2 devra être réitéré si le MSX bascule à un moment sur du 60Hz.

Ces Solutions sont software donc effectivement, cela résout le problème "que" temporairement, mais évite un lourd passage sur la table d'opération en suivant le protocole rapporté par Jipe ^^

En conclusion:
Je ne maîtrise pas le processus et ne saurai donc pas expliquer le pourquoi de ces solutions.
Cependant, je suis tout ouïe pour des explications constructives