Sony Kanji Video Titler XV-J550: the inside

A video titler is the equipment responsible to create title screens, credit lists, captions, subtitles, etc. You know, the kind of video editing that today is done by a software in any computer or even in cellphones. In the XV-J550's days this was done by specialized equipment: the video titler.

Last post we present the XV-J550 and XV-T550 video titlers. One is targeted to Japanese market and the other to western markets, this difference reflects in some changes between both models. Being a video titler, XV-J550's main function is to put text on screen, since it's aimed for Japanese market, it needs to support Kanji characters, so it have, at least, more ROM than XV-T550, to store these Kanji Fonts.

Although they have the same outward appearance, XV-J550 and XV-T550 have different PCBs. Evidence suggests that the XV-T550's PCB was prepared to be shared with the XV-J550, there are some unpopulated placements for ROM on XV-T550's mainboard that can be used by Kanji ROM.

This is the mainboard from XV-T550, take a look in the two unpopulated
placements for ROM chips and the shielding over V9938
(picture from this MSX Village thread)

By now, all (three) XV-J550 that I saw the insides had the same PCB's look (maybe different minor revisions, but the same overall shape). And this PCB's appearance is consistently different from the one that I saw in pictures of XV-T550 and is printed in its service manual:

This is the XV-J550 mainboard seen from solder side.
The two chips that you can see are the Sony custom mapper
and the MSX-System II

And this is the XV-T550 mainboard, picture from XV-T550 Service Manual.
You can see that many components are in different locations on the board.

My guess: the XV-J550 was first released in Japan. Seeing that it's a good product and there is a broader home video market, Sony wanted to sell it in Europe, but had to make some revisions on the board for this release; this new board was meant to be shared by the two versions of the titler (XV-J550 and XV-T550), but for some reason the XV-J550 with the new PCB did not reached the market (or we didn't yet found any XV-J550 with this new board). I believe that, instead release the same old product with a new internal organisation, Sony did launched new video titlers, like the XV-J770.

What's inside XV-J550?

There is two big boards (and some small boards) in XV-J550. One with all the MSX hardware and other responsible to handle the AV inputs and outputs. The designers made a very compact unit, the other video titlers from Sony have almost two times the height of the XV-J550/XV-T550:

XV-J550 on top of XV-J777.

This compactness made the XV-J550 a beautiful equipment, but compromises the "hacking" possibilities. It's impossible to use the cartridge slot  while XV-J550 is closed and is very hard to fit any additional circuitry in this limited space.

How you can use the XV-J550/XV-T550 cartridge slot

XV-J550 have most of what can be expected from a MSX2 system, but it have only one joystick port, one MSX slot and the keyboard connector doesn't have all pins connected to use a complete MSX keyboard.

CPU: Z80 @ 3.58Mhz
RAM: 64KB
VDP: Yamaha V9938 with 128KB VRAM
PPI: MSX-System II
Sound: PSG equivalent inside MSX-System II
Storage: 64KB SRAM energized by a CR2032 battery
Keyboard: separated keyboard customized for video production functions
Additional features: Superimposer
I/O ports: two stereo AV inputs and two stereo AV outputs, one keyboard connector, one joystick port and one MSX slot.

There is no external storage in XV-J550, but you can save your title sequences in the battery backed SRAM. The MSX slot lacks some pins too, namely: +12/-12 volts, SOUNDIN, SW1, SW2 and BUSDIR.

The XV-J550's mainboard. All ROMs are populated, there is
a big OKI chip connected and no shielding over the V9938.
It's in the same position of the XV-T550's mainboard that
we previously show, so you can easily compare both boards.

Without the RAM and ROM chips, the main ICs on processor board are:

Oki M71H003: Unknown
Sharp LH0080A: Z80 compatible
Sony MB64H444:Custom memory mapper
Yamaha S1985: MSX-SYSTEM II
Yamaha V9938: Video Display Processor

Here you can see the Z80, the mysterious OKI chip
and some RAMs and ROMs. You can't see the slot connector
because there is a MegaFlashROMSCC+SD 512 connected there.

The V9938 and the 128KB VRAM

MSX-System II from Yamaha

Sony custom mapper. Probably a Fujitsu MB64H444PF gate array

There is many ROM chips on this circuit board, but I still don't know what is in each one of those. This mystery will be solved when we read the contents of those ROMs in a EPROM reader. Since the Sony HB-F1XD uses the same set of S1985+MB64H444, I won't be surprised if the BIOS and SUB-ROM are also the same in the XV-J550 and HB-F1XD.

The encoder board have a more sparse look and, as said before, handles the AV inputs and outputs. There is only one IC on the backside of this circuit board.

The "other" board

The lonely IC on "other" board backside: SONY D1030

I did not found the usual SONY V70X0 chips inside the XV-J550, they are very common on MSX2 machines that have digitizer and/or superimposer features. But there are a lot of "washed" chips on the encoder board, any of those chips can be a V70X0 IC, so we can't really say that this machine hasn't the Sony video chipset.

Next post, more Sony video equipment!

Sony Video Titlers XV-T550 and XV-J550

Last post we talk about MSX being used in video production, and that made sense to MSX manufacturers reuse their knowledge to build MSX-based appliances to this job.

From Sony

And yes, this idea made a lot of sense. So much sense that we have many video production MSX appliances from at least three manufacturers. Sony is, by a large margin, the most productive manufacturer in this area: I have now four MSX based video appliances from Sony, and the knowledge about other three.

Even with these good news for MSX researchers is always good to remember: not all Sony video appliances are MSXs, a bit worst, most Sony video appliances aren't MSXs. And even some machines with great possibilities are totally unrelated with MSX hardware. We will see more about that on next posts, by now, we will see the XV-J550, the first one cited in the Wikipedia article.

XV-T550/XV-J550

Some of those machines already have some information on the internet. Others are pretty obscure. One that I didn't have but is very well known is the Sony XV-T550; it's a video titler aimed to Western markets, the Japanese version, XV-J550, although almost the same, have less information available. Of course, being a lucky guy, I have the japanese version.

Sony Kanji Video Titler XV-J550, the keyboard and mouse connectors

XV-J550 comes with a very familiar mouse (Sony MOS-1)

And an unfamiliar keyboard

Both machines are, by this blog definition, MSX computers. Being more specific, they are MSX2 computers. They have MSX BIOS, MSX BASIC, and can run unmodified MSX software without any hardware modification.  There is a cartridge slot between the two PCBs, with the machine opened you can connect any cartridge and it will be started when the titler were powered on.

You need to keep XV-J550 opened to use the cartridge slot.
Remember that the cartridge needs to be connected with the label front facing.

There are only two issues: the video output is off, by default, and the PSG sound output goes to a speaker in the controller keyboard. If you have the keyboard connected, you will be with a black monitor and a singing keyboard. If you don't have the keyboard, you will think that nothing is happening and something broked. (Three issues, if you count the fact that the XV-J550/XV-T550 needs to be kept opened, there is no space for a cartridge when closed)

Having the keyboard, the sound is lame, but, at least, some sound will be played. Find a way to turn on the video output is the last item on our "to do" list to allow us to play MSX2 games on those video titlers. Problem solved by NYYRIKKI, who discovered a lot of things about this hadware and provides two modified Disk-ROMs, one for MultiFlashROMSCC+SD and other one for Nowind interfaces, and . Using this modified DIsk-ROMs you can run any disk based software on your XV-T550. Sadly, for me, these Disk-ROMs didn't work in XV-J550.

NYYRIKKI researched the software of XV-T550 (you can get a copy of this ROM and the XV-T550's Service Manual in Hans Otten's page) and found that to turn on the video output, you need to write specific values in address &H4FFF, and fetch a instruction from the ROM on slot 3.1. He did this with this code (comments by me):

; ...
; Here we have some code to detect the XV-T550
; ROM. I removed it all as I didn't know if the
; same bytes were at the same places in XV-J550
; so the code below will run in any MSX.
;
; Which gives some funny effects when I tested if
; the modified Disk-ROM works in a Sony HB-T7
; that have the modem software at SLOT 3.1
; ...
;
; Change the output to PAL/50Hz
;
di                      ; Disable interruptions
ld a,000010          ; Set bit 2
out (099h),a            ;
ld (0ffe8h),a           ; Update the mirror copy
                        ; in RAM
ld a,%10001001          ; of VDP register 9
out (099h),a            ;
;
; Enable SRAM and Video
;
ld hl,4FFFh             ; Switch address
ld e,%10000001          ; Bit 7:   SRAM and Video
                        ; Bit 0-1: map BANK1 on address
                        ;          4000h to 5FFFh
ld a,%10000111          ; Select slot 3.1
call 0014h              ; WRSLT
;
; Fetch a instruction from SLOT3.1
;
rst 30h                 ; Interslot call
db %10000111            ; Select slot 3.1
dw 5270h                ; Address to be called
                        ; it's a RET in XV-T550 ROM
;
; Turn off the SRAM
; (the video continues enabled)
;
ld hl,4FFFh
ld e,000001
ld a,%10000111
jp 0014h

This code needs to have a RET instruction at address &H5270 of the BANK1 in the software ROM at slot 3.1. If the RET is not there, the execution doesn't go back from the CALLF and the machine runs the next instructions from Slot 3.1 with unpredictable results.

While the XV-T550 have the RET instruction in the right place, this not the case of the software on XV-J550 and we got exactly the "unpredictable results" when we test the NYYRIKKI's ROMs on XV-J550. If we want to use these modified Disk-ROMs we need a dump of XV-J550's software and to find a suitable address to be called, one address that have a RET instruction. With that address in hands, we swap &H5270 with it.

To make the things a bit harder, the ROM chips aren't placed in sockets, but they are directly soldered in circuit board. So, to read them in a EPROM reader,  we need first to de-solder the ROM from PCB. And my skills with the solder iron are very bad, great chances to burn something. Better to wait for a friend with good solder iron skills.

Next post, let's see the XV-J550 internals.

EDIT (2016/07/20): Fixed some grammar errors and added some links to other posts and tags.

MSX and video production

Some times find a hidden MSX is a hard job, digging old magazines, finding service manuals, looking in auction sites and, at the end, make a bet and wait to see what will arrive in my home.

Other times you pick your next prey at Wikipedia.

One of the recommended uses of TMS9918A (the video chip used in MSX1) is as a video titler, the "transparent" color is indeed to be used to show the video stream from an external source, not as another name to "black". Being the TMS9918A the VDP of MSX1 computers, it's natural to have some MSX computers targeted to video producing.

Pioneer released their MSX1 with genlock capabilities. Victor released an Yamaha OEM, Victor HC-6, with a superimposer module. Sony did the HB-701FD which, in addition to the superimposer, is one of the few MSX1 that have a embedded Floppy DIsk Drive.

Victor HC-6 propaganda showing the superimposer module
(from MSX Magazine 1984-07)

When the MSX2 was released they came with the V9938 VDP from Yamaha, a video processor that, while keeping the compatibility with TMS9928, adds new video modes with higher resolutions and more colors. Sony cames with some companion chips, to makes easier to superimpose and digitize external images.

With those hardware resources available, many MSX2 with digitizer and/or superimposer features are released by the MSX manufacturers together with their "Video Graphics" software, like "Video Graphics Matsushita", "Video Graphics Philips", "Video EDIPAL", etc.

Philips NMS-8280 propaganda from Italian magazine MCmicrocomputer n.64

Article from Italian magazine MCmicrocomputer n.64
showing the features of Video Graphics Philips
running on Philips NMS-8280

To the computers without the built-in features, there were external cartridges available that could add those capabilities to any MSX2. And we can't forget the ecosystem of  third-party graphic softwares.

Advertising from Brazilian magazine "CPU Informatica",
selling a genlock (GL-150), a black and white digitizer
(DGT-100) and one with 256 colors (DGT-256).

Then we go back to Japanese Wikipedia that says:

"特にビデオタイトラーでは、ソニーのXV-J550/J770/T55Fシリーズや松下電器産業のVW-KT300などの家庭用タイトラーのハードウェア構成は明らかにMSXを応用・流用したものである。ただし、これらの機種では基本はMSXシステムをベースとしていても独自の実装がなされており、特にBIOSなどは大幅に簡略化されMSXとしての機能は望めないなど、簡単な加工程度では汎用のMSXシステムとして使うことは不可能である。"

Which, translated by Google means:

"Especially in the video titler, it is the hardware configuration of the household Titler, such as Sony's XV-J550 / J770 / T55F series and VW-KT300 of Matsushita Electric Industrial, which was apparently applied diversion the MSX. However, in these models base are made own implementation also is based on the MSX systems, general purpose MSX systems in particular, such as BIOS, etc. can not be expected to function as MSX is greatly simplified, with about a simple process it is impossible to use it as."

Hardware that is based on MSX, but had modified BIOS and could not be used as general systems. That makes a lot of sense! The manufacturers already have the hardware, the know-how to built it and, some of them, even the experience to create video editing software. Why not use all that in more equipment and get more money for a R&D that was already done?

So, we start another research front: Video equipment.