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Apple Interactive Television Box

From Higher Intellect Vintage Wiki
Apple Interactive TV (STB3)
Apple Interactive TV (STB3)
Apple Interactive TV (STB3)

The Apple Interactive TV Box is also referred to as the Apple Set Top Box (or STB). Based on a Macintosh Quadra 605 or Macintosh LC 475 board but with added hardware MPEG decoder. The final product was intended to network boot from nCUBE super-computer hardware with Oracle Media Server over a T1/E1 network. The failure of this project is generally attributed to the high cost of deployment as the concept was a little too ahead of its time.

The STB (Set Top Box) project appears to have started around 1992-1993. The STB3 model used in test deployments is dated around 1995. The entire project was shutdown by about 1996.

General Info[edit]

Apple Computer assigned model number M4120 to this system (possibly specific to the STB3 unit).



  • According to sources in discussion forums over the years, getting video output from these systems has not been accomplished by hobbyists likely due to the lack of specialized software drivers. Without the original Oracle based boot system and image, you're only option is using the external SCSI port with a standard MacOS image.
  • With a SCSI drive connected, supposedly holding down the Option key on a connected keyboard will make the system boot off the disk.
  • The RJ45 port labeled "Network" is very likely E1/T1 only and not Ethernet. With the consumer ROM, the Set top box will not boot fully unless it can download an OMO (Oracle Media Net) application over this interface - this is why the boxes appear dead/not bootable.
  • The Development box has a Different Boot Rom to the normal Boxes. The Normal boxes booted from the ATM AAL1 Network which was connected to a nCUBE Media Server (Later known as Video Server).
  • It seems that initial video signal only outputs on units with the red colored ROM SIMM (likely the one with LC 475 on the label) whereas units with a green SIMM likely won't until the necessary components are provided over the netboot.


This is an earlier "prototype" system built in a metal case. An LC 475 board was used but the LC PDS connector was modified to be on the underside of the board, as the second system board with the TV connections sat underneath. The power supply appears to be from a Macintosh IIsi. These units may have a floppy drive integrated in the case.


  • Base system: LC 475 68LC040 25MHz, 4MB board memory
  • MPEG Decoder: C-Cube CL450
  • Display planes: 2
  • Graphics plane resolution: 640x524, 8-bit color
  • Graphics output: SCART/UHF
  • MPEG Transport Stream: proprietary framing
  • Network: G.703 @ 2.048 Mbit/s, RS232 @ 9.6 kbit/s


This version of the Set Top Box is believed to be unreleased by Apple for any sort of deployment tests.


These are the more common units found online and were also the ones used in the BT test deployment.

To open the ITV, you remove one screw from the rear panel and lift the top cover off. Inside, there are plenty of standard Mac parts, including the 68040 cpu, NCR 53C96 SCSI controller, Zilog Z8530 serial controller, the 3.6V PRAM battery, CUDA switch, and a 72pin SIMM socket, which appears to have a 4meg SIMM installed. There also appears to be another 4meg of RAM on the mainboard. There are 4 cable connections going to the mainboard: the PSU, the input (ADB?) port on the right side panel, the IR receiver, and the front-panel mounted on/off switch. All other ports are mounted directly to the mainboard itself. Just forward of the RAM is a mounting spot for a fan, though in this unit neither the fan nor the cable to supply power to it from the PSU are present.

Now is where the hardware get's interesting, as promised by the ports on the rear. First, near the RAM soldered to the mainboard is a socket which has a 64-pin Apple Flash SIMM installed, labled 'LC 475 GM', which contains 2048k of CMOS flash memory in the form of 8 (256k x 8) Intel E28F020 flash memory chips. Next to this is the Aztec power supply. Near the NCR and Zilog chips is the video decoder, a Philips SAA7188A, which is able to encode video data to NTSC, PAL, or S-video formats. On the other side of the mainboard is the MPEG decoding chip from C-Cube Microsystems, labled 'CL450-P160'. I've also seen mentioned that not only is MPEG decoding supported, but the hardware in the ITV is also said to support Quickdraw and Quicktime. There's also a retangular plastic frame which corresponds to the external expansion cover and which extends nearly to the front of the casing. At the forward part of this plastic frame is an expansion socket, somewhat like the PDS expansion slot of the LC-series Mac's, though this connector runs parallel to the front of the casing, not along the rear portion of the side panel. Also near the MPEG decoder is a XILINX XC4010-4 FPGA (Field Programmable Gate Array), which can be seen as a reconfigurable processor though it is unclear exactly what it's function is in this case. To the rear of the XC4010-4 is a ROM labled 'STB3 A3.1N 551AA6'.

The Apple part number for the STB3 mainboard is 820-0638-01 and dated 1995.


  • Base system: LC 475 68LC040 25MHz, 4MB board memory
  • MPEG Decoder: C-Cube CL450
  • Display planes: 2
  • Graphics plane resolution: 640x524, 16-bit color
  • Graphics output: SCART/UHF/S-video
  • MPEG Transport Stream: MPEG2 transport stream
  • Network: G.703 @ 2.048 Mbit/s, RS422 @ 9.6 kbit/s

TattleTech Output[edit]

• Nubus/PDS Slot# = $00
◊ Board Name = MEMCjr Built-In Video 
◊ Board ID = 77
◊ Vendor ID = Apple Computer, Inc. 
◊ Revision Level = Macintosh CPU Family 4.1 
◊ Part# = The HORROR Continues 
◊ Date = 15-Jun-93
◊ Functional Resources :
+ Device sResource Name = CPU_68040
- Device Category = 10 (CPU)
- Device Type = 5 (68040)
- Device Software Interface Type = 0
- Device Hardware Type = 24
- Device sResource# = $FB
- Driver Number = [NA]
• Nubus/PDS Slot# = $0C
◊ Board Name = Kevin STB3 
◊ Board ID = 1661
◊ Vendor ID = Video Architecture Group 
◊ Revision Level = A3N Xilinx 3•28 SW 3•28•95 
◊ Part# = STB3 
◊ Functional Resources :
+ Device sResource Name = Display_Video_Apple_GM
- Device Category = 3 (Display)
- Device Type = 1 (Video)
- Device Software Interface Type = 1
- Device Hardware Type = 2
- Device sResource# = $81
- Driver Number = -49

Two 'video interfaces" are being detected by TattleTech.

MEMCjr is the video and memory controller that is left over when the LC475 turned into STB. This won't get us very far because the rest of the LC475 video hardware is missing.

Kevin STB3 is the new video controller that drives composite displays and it is associated with the driver Display_Video_Apple_GM. Normally this would be a DRVR resource in the video card for a NuBus board or it would be present in the logic board ROM. Obviously it is missing...

ROMDefs.h Hints[edit]

Part of what seems to be QuickTime source code, ROMDefs.h which is "NuBus card ROM Definitions" appears to make STB references:

enum {
  displayVideoAppleGM           = 16843010L, /*Video with Apple parameters for GM card.*/
  drHwSTB3                      = 0x0002, /* Assigned by Kevin Mellander for STB-3 hardware. */
  drHwSTB                       = drHwSTB3, /* (Both STB-3 and STB-4 share the same video hardware.) */


Video Architecture Group[edit]

The "Video Architecture Group" mentioned in the vendor ID of the output above appears to be an internal division of Apple (as noted on the last page of Also seeing "Xilinx" in the output potentially indicates the display adapter is controlled by that chip as mentioned in the component list below. We can also reference this interview with Nick Baker who was a member of this team at Apple:

After graduating from Imperial College London in 1990 he found his way to Apple and worked on the team that tried to create a specialized video card.  He then went to 3DO where he worked on their high-end gaming system which, unfortunately, failed in the market. 

>> Nick Baker:  The Video Products Group got split up.  It was more a Video Architecture Group.  I can't remember exactly what we called ourselves.  But we were looking at more focused on pulling in video onto the motherboard.  So as you--as Apple computers came out, they had video capability being built into the motherboard.  We were speccing those chips.  We weren't necessarily doing the designs ourselves anymore.  It was working with Phillips and others to do the silicon.

>> Nick Baker:  For base band video back then it was NTSC Pal.  HD was still far off.  From that standpoint it was at least supporting uncompressed video.  It was as good as probably you needed for a while.  We put in architectures to have a parallel pixel bus so the role band would suddenly need to go through main memory, for example. And then probably the idea was to have a slot that you could addin a compression card, for example, that somebody else could do.  But if you looked back at the last 10 years, then it's been quite an explosive raise of growth there in the capabilities.

As seen in the above information, the team worked with Philips for the actual board components. The section below mentions the Philips SAA-7188A-WP component on the STB3 board. Our assumption is that Philips component might be responsible for the actual video output hardware.

Mainboard Components[edit]

C-Cube MPEG Decoder CL450-P160[edit]

MPEG decoder, also found on the Apple MPEG Media System expansion card

Xilinx XC4010 -4 PQ208C X44364M[edit]

FPGA which we suspect does some sort of video display work as "Xilinx" also shows up in the STB display hardware properties. This may also be used for translation between video systems and PDS.

Apple 343S0138-A[edit]

this chip is also present on the Power Macintosh 6200 board and we suspect it is related to comm/PDS


Brooktree Bt8069-Series Line Interface Unit (LIU). A line interface unit (LIU) is a semiconductor device that implements the T1 or E1 protocol in hardwired silicon.

Philips SAA 7188A WP 641472[edit]

Encode digital YUV video data to an NTSC or PAL CVBS or S-Video signal. Digital Video Encoder (DENC2-M, SAA 7188A) (possible reference: Philips Semiconductors Desktop Video Data Handbook, June 1994). It is also interesting to note that a similar chip Philips SAA7194 is found on the AV card for the Power Macintosh 6100 which has S-video output. Prior to the SAA7194, the Quadra AV design used the DMSD chip SAA7191 and VDC chip SAA7186. The SAA7194 apparently combines these.

NCR 53C96 609-3400665[edit]

SCSI controller also found on Macintosh LC 475 and Macintosh Quadra 605

Zilog Z0853008VSC Z8530 SCC[edit]

Controller for the RS-422 serial port as found in numerous Macintosh models.

VLSI 343S0164-b Apple[edit]

MEMCjr memory controller. Found in similar Macintosh models.

DSP TMXE320AV110PBM EA 52AJN1W[edit]

Texas Instruments. Assumed to be an audio processor.

A4 E1 NTSC 341-0783 23/1/96[edit]

Mainboard Comparison[edit]

Among the STB3 units there are some notable differences in the mainboard, seemingly based on how far along in development the unit happened to be.

In the above picture, the board on the left has 4 components located behind the T1/E1 network port. In almost every other STB3 board photo (example on the right side), these components are missing. The board with these components does also have a visible green wire connecting two other components. As that is not present on most other STB3 boards, we suspect that would have been an earlier production run.

Getting TV Output[edit]

The STB3 does not produce any TV output using the "final" mask ROM in North American NTSC units. A user on 68kmla forums was able to get some initial video from an STB3 with ROM 7.0 (red flash SIMM, not mask ROM).

This is likely at the point where it is attempting to netboot via the T1/E1 interface. This particular ROM might not allow the system to SCSI boot, but at least it does provide proof of a working video system.

Developer Video Card[edit]

Inside the STB3 is what appears to be a "PDS-ish" type of connector which would then require a right-angle adapter in order to accommodate a horizontally mounted expansion card. In some online auctions for STB3 units, a video card with the traditional Macintosh DB15 port has been included. This is a fairly rare option and we don't have any reported cases of hobbyists getting any output from the card. At least one forum user reported this was for machine development and likely the software driver was installed over netboot.

This card is apparently from MicroConversions, but we're not aware of a working driver still out there. The card does slightly resemble the MicroConversions 2124NB II Macintosh NuBus card which was released in 1995 (see below).

There is also an LC PDS version of this card MicroConversions 1724PD so it is possible that the STB3 developer video card is a version of one of these cards.


(download URL:

This archive of Set Top Box specific software components has been floating around the Internet for a number of years. We're not sure if these were used in the netboot images used in the trial deployment testing, but users have not been successful in having these let the Mac OS work with the STB video ports.

  • KeyColor
  • MoviePlayer - version 1.1d1 reported in About box
  • QuickTime - indicates version 2.0 in info box
  • Quicktime 11/15 - indicates version 1.7d0 in info box
  • E1Component - strings found inside this with ResEdit indicate this is for "Apple E1 Card" so logically T1/E1 network support on the STB board
  • Apple E1 Player - indicates version 0.1b1 in info box. When opened, says it is the STB E1/T1 Simple Player and appears to look for E1 video feed.
  • Serial Tool
  • TSDrvr INIT - indicates version A1.3 in info box. Notes on another site indicate this is probably a ColorSync extension.
  • TSDrvr INIT - 12/13

None of the above appear to activate video output using the composite or coaxial connections. TSDrvr resource strings mention MPEG1 and MPEG2 so we believe this is used by the MPEG decoder chip.

Under system 7.5.5, the TSDrvr INIT causes a bomb crash during the boot process both on our test LC and seemingly on the STB as well (no video output but boot process seemed to halt). Might only work under 7.1.x.


The nVision solution includes a deskside nCUBE media server and digital set-top box technology from Apple Computer, Inc., for delivering interactive content through a television set. The system is compatible with leading media server software such as that in use at Bell Atlantic and BT. The nCUBE media server itself provides 10 GigaBytes of disk storage, 16 I/O channels, a CT3 interface for T1 streams, and an ATM interface for E1 streams. Networking components for the system are provided by Alcatel and Telco Systems.

"Apple is leveraging its QuickTime multimedia and QuickDraw graphics technologies for use in its interactive TV set-top box," said Rick Shriner, vice president of Apple Core Technologies. "We believe the nVision system, which includes Apple's Interactive TV Box technology, will enable Interactive TV trials to come on line quickly. It will also serve as a proving ground for content and service developers who are working to create the compelling interactive television applications necessary for this new industry to succeed."

BT Tech Info[edit]

The set-top-box (STB) is based on an Apple Macintosh computer - the LC475 - running MAC O/S modified to support MPEG and a 2 Mbit/s network interface. At start-up it is downloaded with the application and Oracle Media Objects (OMO), the run time version of the authorware tool in which the services are created.

The network platform is being delivered by Alcatel Network Systems and comprises STM-16 SDH rings delivering content from the media server in Colchester to six remote telephone exchanges based in Colchester and Ipswich. Alcatel's ATM technology switches individual video and control channels at the remote exchanges where they are delivered as a 2 Mbit/s stream over either copper using asymmetric digital subscriber loop (ADSL), or fibre.

The ADSL technology, manufactured by Westell International, delivers over an ordinary telephone loop 2 Mbit/s in one direction, a 9.6 kbit/s bidirectional control channel, and the ordinary analogue telephone service. Fibre customers are connected using Alcatel's APON technology.

The Alcatel switching platform provides the concentration and distribution to allow up to 1200 of the 2500 customers to be connected to the server at any one time.

The server system consists of an nCUBE massively parallel computer controlled by a Sequent Unix computer both running Oracle's Media Server software. The significant advance in server technology since the earlier trial has been the ability to scale the server to allow up to 1200 customers independent access to 1000 hours of entertainment as well as the other applications. There is an EDI gateway to the server supporting the banking application.

All the video content compressed is to the MPEG1 standard at 2Mbit/s and carried in MPEG2 frames. The coding of all the short video sequences and bitmaps is carried out by BT using real-time coding technology.

Business support services utilise Oracle's database software and applications and all the significant components of the system are integrated with BT's normal billing, network management and customer service systems (CSS).

Capacitor Replacement[edit]

The STB3 logic board uses SMD capacitors known to leak electrolyte with age. These should be replaced to avoid damage to surrounding components.

  • 47uf 16v x 11
  • 10uf 16v x 17
  • 100uf 6v x 2
  • 100uf 10v x 1

The power supply will also contain leaking capacitors. As this is simply an LC based power supply, refer to the repair section of our Macintosh LC 475 page for a capacitor list based on PSU vendor.


The green mask ROM found in most of the Set Top Box units seems to be close to a Quadra 605 or LC 475 ROM. These do not produce any video output, but the system accepts an external SCSI boot volume and functions like a normal Macintosh. The red developer ROMs of which there seem to be numerous versions are much different. The red ROMs will produce a video output but not accept a SCSI boot volume. A deep analysis of the red ROM was done in and it reveals that an HFS volume exists on the red ROM containing a very minimal variation of System 7.1. This volume is named "HappyDisk" as seen below:

The System file seems to be a standard 7.1 version but with most of the unused parts removed. The Finder is simply an application which contains reference to something called "FredTV" and likely just waits for an MPEG stream.


The most notable test deployment of the Apple Interactive TV is with BT in the UK. We believe the STB units were also tested in a hotel under the Disney brand.

Apple and Bell Atlantic conducted trials in six states in the United States. Network functionality was provided by Oracle Media Net, which would download a "stack", a multimedia runtime application that was authored with Oracle Media Objects. Interactive educational programming was provided by The Lightspan Partnership. For units tested in the Washington, D.C. area, MPEG-1 content was streamed at 1.5 Mbps over an asymmetric digital subscriber line, a technology that was being developed by Bell Atlantic subsidiary Bellcore. Bell Atlantic ran their service trial on four nCube servers, which could each store up to 10,000 feature-length films. (from

By the spring of 1994 Apple became the number one supplier of set-top boxes in the UK. The business world projected that Apple would have installed over 600,000 set-top boxes in the UK by 1995. To put that number in perspective, there were already that many Macintosh computers there in 1994. Disney even purchased complete systems for its theme parks. It put the Apple boxes in guest rooms and provided content, tours, and entertainment for its guests. (from

Known Cable Providers Using The Apple Interactive Television:

  • Telia (Sweden)
  • Telenor (Norway)
  • Plein Cable (France)
  • British Telecommunications (UK)
  • Bell Atlantic (USA)




External Links[edit]

See Also[edit]