The Philips CDI 310 EMC/EMI Testing Unit is a transportable CD-i player with an integrated floppy disk drive, showing multiple signs of being a pre-production unit built for EMC/EMI compliance-testing. It appears to have been custom-built out of a CDI 350 rather than manufactured as a standard retail model.
Advertised as the Philips Transportable CD-i System with floppy disk drive, the Philips CDI 310 likely never reached the market in significant numbers. According to Philips’ product introduction sheet, the model was positioned as a professional multimedia platform combining a CD‑i player, floppy disk drive, and pointing device for institutional or professional use. The floppy drive was intended for storage and updating purposes, making the system suitable for training, presentations, and POI/POS installations. Only a handful of 310 units have surfaced so far, which makes the one documented here particularly special.
Like the other portable Mini MMC-based models, it was manufactured by Marantz. This hardware generation is known for leaking SMD capacitors, something I have documented in my CDI 350 repair articles. Because of this, I powered the unit on only for as long as absolutely necessary to avoid causing further damage. I captured a few screenshots, attempted to initiate a serial connection and tried to read a floppy disk. As expected, it suffers from bad video output, and both the floppy disk drive and serial connection fail to function as intended. The CD functions are very likely affected as well, although I did not test them.
Noticeable differences
Compared with the CDI 350, one difference immediately catches the eye: there is no screen and the entire top section of the case is closed. The top cover and the extension port cover differ completely from the rest of the chassis, almost as if they were never part of the same design. The usual labelling Philips Portable CD Interactive / Floppy Disc Player CDI 310 Multipurpose System is missing. At first glance, it might seem that somebody removed the typical rubber coating, which becomes sticky over time as the softener escapes, and repainted the surface. However, this is unlikely, as this unit clearly precedes the retail versions.
A regular CDI 310 unit shows the correct labelling and a matching top surface (photo courtesy of CD-i Fan):
The remainder of the chassis appears to come from a CDI 350, although the areas for the display button and the brightness dial are covered with a sticker. Parts of the original labelling (Display On/Off and the in portion from Video in/out) have been removed.
Side of the CDI 350 with 22ER9142 DVC dock (top) and CDI 310 EMC/EMI Testing Unit (bottom):
Bottom of the CDI 350 (left) and CDI 310 EMC/EMI Testing Unit (right). Note the low serial number (000005):
Top assembly
In order to remove the top cover, we first need to open the expansion socket cover. The view here should give us a glimpse of what we’re dealing with: lots of copper tape.
Once the top cover has been removed, you’ll notice that copper tape is attached everywhere. This immediately complicates disassembly and will almost certainly make reassembly even more challenging later on.
Everything looks a bit makeshift, as if it’s been cobbled together for testing. Small pieces of the plastic have been snapped off, and ordinary nuts are used as spacers for the FDD controller PCB. Despite this improvised appearance, both halves of the top section were clearly manufactured specifically for the CDI 310 and not borrowed from a CDI 350.
The top assembly attaches to the main chassis at the point where the screen hinge is located on the 350, but otherwise it is rather unstable and held together at the rear only by the extension socket cover.
FDD controller PCB (PD06 WI284K1000)
The CDI 310 FDD controller PCB features a National Semiconductor DP8473 Floppy Disk Controller PLUS-2 chip, 64 KB of SRAM, a PAL device, several 7400-series logic ICs and a small power circuit. No service manual or schematics exist for this board, but the overall combination of components looks strangely familiar — especially the PAL marked 7117. This mix of parts also appears on the floppy-controller boards used in the larger Maxi MMC and Mini MMC models, such as the one in my CDI 605T. Although there is still no service manual for those units either, the Technical Documentation for CDI 605T Users, chapter 10 Floppy specification, provides a useful explanation of how the controller works and helps in understanding the architecture seen here.
The connection to the mainboard is made through several flat-flex cables. One FFC runs from JL06 to J402 of the mainboard, which is a bit odd because J402 is the screen connector on the CDI 350. Four additional FFCs (JL01-JL04) lead to the mainboard’s extension socket (J606). The FDD controller PCB also includes a feed-through extension socket (JL05) for connecting the 22ER9142 DVC dock, allowing the 310 to retain compatibility with the CD-i Digital Video Cartridge.
The PCB itself looks as though it has been assembled by hand, with uneven solder joints and flux residue on both sides. And, of course, the SMD electrolytic capacitor is leaking.
Key components and markings
This section documents all markings, identifiers, and major components found on the FDD controller PCB. If you prefer to skip ahead, you can jump directly to the floppy disk drive.
Markings:
E67S 12HV-0
PD06
WI284K1000ICs
QL01 - DP8473V
(N) S9152AH F
DP8473V
1987 (c)
[DP8473 Floppy Disk Controller PLUS-2]
QL02 - 64K-RAM
SANYO
LC3564QM-10
JAPAN 23678
[64K (8192 words x 8 bits) SRAM]
QL03, QL04, QL05 - 157
T 9324H
74HC157A
[Quad 2-Input Data Selectors/Multiplexer]
QL06 - 4040
T 9324H
74HC4040A
[12-stage binary ripple counter]
QL07 - 20
T 9314H
74HC20A
[Dual 4-input NAND gate]
QL08 - 85
T 9304H
74HC85A
[4-bit magnitude comparator]
QL09 - 245
T 9252H
74ACT245
[Octal Bidirectional Transceiver with 3-STATE Inputs/Outputs]
QL10 - 27
T 9239H
74HC27A
[Triple 3-input NOR gate]
QL11 - PAL
(Ti) 16R4-25C
12??? TIBPAL
Label 7117
[LOW-POWER HIGH-PERFORMANCE IMPACT PAL CIRCUIT]
QL12 - 123
T 9324H
74HC123A
[Dual retriggerable monostable multivibrator with reset]
QL13 - BP5005
ROHM
BP5005
9318
[DC-DC converter]
QL14 - 74
T 9240H
74HC74A
[Dual D-Type Flip-Flop with Preset and Clear]
QL15, QL16 - 02
HC02
9229Y7
[Quad 2-input NOR gate]
QL17 - 32
T 9241H
74HC32A
[Quad 2-input OR gate]
QL18 - 08
T 9315H
74HC08A
[Quad 2-input AND gate]
QL19 - 7407
SN7407
(Ti) 8CF
[Hex Buffers and Drivers With Open-Collector High-Voltage Outputs]
QL20 - 04
T 9316H
74HC04A
[Hex Inverter]
QL40 - 244
T 9322H
74HC244A
[Octal 3-State Noninverting Buffer/Line Driver/Line Receiver]Crystal
XL01 - 24MHZ
S24.000
KDS 2HConnectors
JL01, JL02, JL03, JL04 - to mainboard J606 (extension socket)
25 pins, FFC
JL05
100 pins (extension socket)
JL06
25 pins, FFC - to mainboard J402
JL07
26 pins, FFC - to FDDCapacitors
CL22
10
10V
leaking
CL32 - +12V
ELNA
(M)
25v100µF
CE85°
9244
(U)
CL33 - +5V
ELNA
(M)
6.3V1000µF
CE85°
9031
(U)Mitsumi F359F2
The floppy disk drive in the CDI 310 is a slim Mitsumi F359F2, which, coincidentally, has a similarly low serial number. I have not taken the FDD apart yet; however, detailed photos of this model are available on Wikimedia Commons.
Main chassis
The main chassis of the CDI 310 isn’t quite so easy to take apart, as four FFCs from JL01-JL04, which feed into a single board with edge connectors, are firmly attached to the extension socket using copper tape. After some careful prying, I finally managed to loosen it and separate the assembly. At first glance, the interior does not look much different from a 350, apart from the occasional strip of copper tape applied for additional shieldung.
You will also notice that the speakers are missing – hardly surprising, as speakers serve little purpose without a display. The CD mechanism (CDM 9) mounted on the mainboard and the small circuit board for the power connection (aka PP06 POWER CONNECT PANEL) to the right of the mainboard are already familiar from the CDI 350.
Mainboard (PM06 WY282K001-0)
Let’s take a closer look at the CDI 310 mainboard (aka PM06 MAIN PANEL). Don’t be put off by the yellow silkscreen – this is perfectly normal. Although the unit I repaired in the 350 repair articles has white silkscreen, there are also mainboards with yellow silkscreen that are functionally identical.
As expected, this unit shows the usual signs of leaky capacitors and the resulting damage. A few details stand out straight away: the system ROM with a handwritten sticker bearing the date 93-7-10, as well as traces of soldering work and components that have been removed or replaced.
Read part 2 for a detailed comparison with the CDI 350 mainboard.
Credits
Many thanks to CD-i Fan for providing information and photos of a regular CDI 310 model.
History
2026-08-25: Initial version published
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