Monday, September 12, 2016

Sony Kanji Video Titler XV-J770 and XV-J777

The last Sony equipment that we saw was the XV-T600, which is not a MSX. That's not fair, Sony was a big supporter of MSX standard and, most important to this blog, sold many devices powered by MSX technology. To repair this injustice we will examine two Sony Kanji Video Titlers at once: XV-J770 and XV-J777.

The XV-J770 is in Wikipedia's list and we can see it in the MSX Magazine's pages:

Picture of Sony XV-J770 from page 79 of MSX Magazine 1990-04

If you have a good eye (and good memory), the mouse of XV-J770 is the well known Sony MOS-1, the same one that Sony sold for their MSX computers and is included in XV-J550. The small controller keyboard is the same of XV-J550 too. Although not famous as its cousin XV-J770, XV-J777 have a very close look.

Pile of Sony Kanji Video Titlers.
From top to bottom: XV-J550, XV-J770 and XV-J777.
The silks are the only difference that can be
spotted between XV-J770 and XV-J777.

The keyboard and mouse connectors
are the same on all three models.

They have the same high and are both taller than the XV-J550, which gives more space inside their cabinets. More space is a good thing if you think in to hack those machines. They are high enough to put a small cartridge, and the XV-J550 have a internal MSX slot. The expansibility of the XV-J770 and XV-J777 looks promising.

From behind, all connectors are the same, Sony included
S-Video output on those machines. The XV-J777's rear metal
plate is painted in black while in XV-J770 it's in bare metal.

Both units have a power outlet to connect other equipments
(in this picture the power outlet of XV-J777
is obstructed by XV-J770's power cord)

Another difference between these two titler's models and the previous one, the XV-J550, is the presence of a external mass storage. They have a slot for IC Cards, this way the user isn't stuck with the internal storage, which is a small (16KB) SRAM backed by battery. With all this storage available, the front of both titlers have a button row to select between the many data banks saved.

The two video titlers have a button row to select which
of programmed title sequence will be used. The door
below those buttons protects the IC card slot.

Behind the doors, the IC card slot.

What's inside XV-J770 and XV-J777?

The internals of those two video titlers aren't the same, while they are still very similar. In a Sony's catalog from 1991 those two equipments are announced and the only listed difference between XV-J777 and XV-J770 is that XV-J777 comes with an IC card. So I guess that the internals of those two machines are intended to be the same but I have two different revisions of the main board. Probably if someone buys many of those titlers we will find some XV-J777 and XV-J770 with the same board.

Lucky us, so we can see two different boards (though very similar):

Main board of Sony Kanji Video Titler XV-J770

Main board of Sony Kanji Video Titler XV-J777.
You can see, at lower of this picture, the "included"
64KB IC card inserted in its slot.

The first thing that I noticed after open the titlers was: there is no slot connector. Damn. The XV-J550 have a MSX slot connector, but doesn't have internal clearance to put anything in this slot. The XV-J770 and XV-J777 have room to put a cartridge but doesn't have the connector.

The component side of the board have the main processor (Zilog Z80 in my XV-J777 and Sharp LH0080A in my XV-J770), the VDP (Yamaha V9938) and the respective ROMs and RAMs. As the boards are almost the same, I'll use the XV-J777 pictures:

The first column of IC's are all ROMs; the second column
have, from top to bottom, two SRAMs (8KB each), the CPU (Zilog Z80) and,
lastly, another ROM. At bottom right two groups of RAMs.

At top, a bit blurred, you can see six RAM ICs,
64KB as Main RAM and 128KB as Video RAM (in the
previous picture you can see better these chips).
At bottom, the MSX2's Video Processor, the Yamaha V9938.

We already have many items to identify these two machines as MSX based: Z80 CPU, V9938 VDP, VRAMs, RAMs, etc. We still need to check the ROMs and to find the PSG and PPI equivalents.

At solder side the two boards are almost the same, too:

The solder side of XV-J777 main board

And the one from XV-J770

The solder side gives to us more items in our MSX based checklist, there we can see the PSG and PPI equivalent, the MSX-System II (Yamaha S1985) and a Sony custom memory mapper (Sony MB64H444).

The two QFPs at middle are the Yamaha S1985 and the Sony MB64H444

To eliminate the last item on our checklist, Tabajara saved the contents of all those ROMs from XV-J777 and now we can confirm:

00007ed0  01 09 00 09 22 62 f8 c9  4d 53 58 20 20 73 79 73  |...."bøÉMSX  sys|
00007ee0  74 65 6d 00 76 65 72 73  69 6f 6e 20 32 2e 30 0d  |tem.version 2.0.|
00007ef0  0a 00 4d 53 58 20 42 41  53 49 43 20 00 43 6f 70  |..MSX BASIC .Cop|
00007f00  79 72 69 67 68 74 20 31  39 38 35 20 62 79 20 4d  |yright 1985 by M|
00007f10  69 63 72 6f 73 6f 66 74  0d 0a 00 20 42 79 74 65  |icrosoft... Byte|

They are MSX based machines!! These ROMs will be the subject of another post (hey, there are a lot of ROM ICs to be analyzed)

Another nice detail in solder side is the board manufacturer name: Mitsumi Elec. Co. Ltd. Mitsumi was the only manufacturer in the list of MSX licensees that didn't built any MSX (NEC did some MSXs for Philips). Even doing these PCBs at Sony's request, I guess we can now say that Mitsumi built at least these MSXs.

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