Pioneer UC-V102 - Part 3

In this post we will finally see what you got with a Pioneer UC-V102.

What's Pioneer UC-V102

It's a MSX2 computer, a very expansible MSX2 computer. It already come with a FDD controller and two floppy disk drives, a RS-232C serial interface, superimpose capabilities and many slots.

Front: (first row) Floppy Disk B and A (3.5" DD), reset button;
(second row) power button, MSX cartridge slot (50-pins),
controller 2 and 1 (DB9 male)

Back: There is four sets of RCA connectors, each one is Video+Audio L/R:
top-left, top-right and bottom-left are for Inputs; bottom-right is the output,
then the RGB21 connector (also an output) and the stereo/mono selector.

In the middle block there are three 100-pins "custom" slots, the keyboard
connector (Hirose QM40-26PA-EP), printer port (Centronics 14-pins female)
and RS-232C (DB25 female).

At right is the power supply, with a power jack and a power cord.

The slot map of Pioneer UC-V102 is a bit unusual with RAM in slot 0/2. For some reason the MSXMEM2 always counts 256KB of memory mapped RAM on this machine; with or without my SD-Mapper connected (which have 512KB RAM).

MSXMEM2 output. The slot 1 is the external cartridge slot,
with a SD-Mapper connected. You can see that we have RAM
in slot 0/2 (built-in) and in slot 1/3 (SD-Mapper)

Without the SD-Mapper connected, TestRAM finds the correct amount of RAM, 64KB. With the SD-Mapper connected it hangs while detecting the Memory Mapper.

TestRAM running without an external Mapper connected

The actual slot map for Pioneer UC-V102 is:

SLOT0-0: MSX-BIOS
SLOT0-1: MSX2 SUB-ROM
SLOT0-2: 64KB RAM
SLOT1: External
SLOT2-0: MSX-SERIAL
SLOT2-1: Internal
SLOT2-2: Internal
SLOT2-3: Internal
SLOT3-0: MSX Disk-ROM
SLOT3-1: Internal
SLOT3-2: Internal
SLOT3-3: Internal

Wow! You can see that this machine have a lot of expansion opportunities! At front it have one primary slot cartridge and, internally it have six secondary slots. The 100-pins expansion slots are, for real, two 50-pins slots, side by side.

The Pioneer UC-V102 expansion slots

Each column of three slots goes to a connector in motherboard, named "Expansion SLOT A" and "Expansion SLOT B". Pioneer sold some expansion boards to use in UC-V102: the dual serial board (with two of those, the Pioneer UC-V102 could control up to five Laserdiscs) and the digitizer board. No pictures of any of these boards, but I guess that the "dual serial" board is (more or less) two MSX serial interfaces glued together. I still did not test MSX cartridges in these slots, but I hope to do that soon.

I did the ROM dump from all slots that have a ROM installed using the SAVEROM and did put the extracted files on this ROMs tarball. The files named UCV102PS.SLT are full dumps (0000h to FFFFh) of primary slot P and secondary slot S. The files with .ROM suffix are only the memory pages where MSXMEM2 shows there is a ROM installed.

Examining the DISK.ROM, we can found an Easter Egg showing that not only the UC-V102 keyboard was borrowed from Mitsubishi ML-G30:

This bios program is coded by T.Osada
This hardwear is developed by M.Ishikura
This casing is designed by N.Miyazaki
Consumer's electric product development section
GUNMA Works , MITSHUBISHI ELECTLIC SOCIO TECH

I really don't know what to think about that. The machine looks like a work from Pioneer, there is a Pioneer ASIC on the mainboard. We already saw Mitsubishi's keyboard being used in MSX computers from other brands, so it's not so surprising see the same keyboard with Pioneer UC-V102, but the use of same DiskROM opens some doubts: Did Pioneer copied this ROM without the Mitsubishi knowledge? It was a licensed work? Mitsubishi had something more with this machine?

These doubts will remain open and maybe will never be answered. While we wait those answers, let's see the Pioneer UC-V102 hardware. In our next post.