Regarding
the STB2
By Anubis
REGARDING THE SECOND REVISION OF THE APPLE SET TOP BOX PROTOTYPE
Back in 1995, Apple manufactured a prototype set top box for
use in a trial run of an interactive TV service in Great Britain.
The service, as near as I can tell from what little information
I have gathered,was supposed to provide video-on- demand and
pay for view services and less than 1000 of the STB2's were made.
I have obtained one of these prototype units, and the following
is all the information I was able to obtain from dismantling
and testing it.
EXTERIOR APPEARANCE
The STB2 is about the size of a small VCR, but only half as
thick. The top of the unit features a sliding cover secured by
a single black metal screw in the rear of the unit. Case screw
damage to the back of my unit indicates it had been opened prior
to my obtaining it. The front of the unit is made of black plastic
and slightly curved out to the front. In the center of the front
panel is a 1/2 inch by 1 inch piece of translucent black plastic
with a rainbow Apple logo on the upper portion, and an infrared
receiver behind the lower. I am told that this is not a full
IRDA port, but merely a receiver for the remote unit, which I
do not have. At the left edge of the front is a round Power button
and a red indicator diode. On internal investigation it appears
this power button is wired to pin 2 of the onboard ADB interface,
and functions similar to the soft power key on standard Macintoshes.
The left side of the unit has no distinguishing features but
the right side mounts a standard ADB port and a security sticker
applied by its previous owner. The bottom of the unit is made
of unpainted sheet metal with four twist-lock plastic feet and
an FCC sticker, warning that the unit has not been approved by
the FCC and can not be sold in the US. The bottom is completely
devoid of all the other product stickers, serial number stickers,
barcodes, and safety warnings that you find on a released product.
The rear of the unit features all of the interesting stuff.
There are three RCA jacks for left and right audio out and video
out. There are two composite coaxial RF jacks, one for input,
and one for output, and a switch to select between channel 3
and 4. There is an HDI 30 SCSI port, similar to the SCSI ports
found on Powerbooks. There are SCANTV and SCANVCR ports that
are covered by plastic DO NOT REMOVE plugs. There is a standard
Mac serial printer/modem port, an Ethernet port, and an S-video
port. There is a standard three prong power input socket and
a toggle power switch. And last but not least there is a plastic
expansion card slot cover, that is secured by two metal screws
and also covers up the units security slot.
INTERNALS
Internal access to the STB2 can be obtained by removing one
screw in the rear of the unit and sliding the cover off. Inside,
the units CPU is a 68LC040 processor and there is also a dedicated
MPEG decoder chip. I have been told the motherboard is based
off of an LC 475 series Mac. The unit had a single 72 pin SIMM
slot that was empty, the unit also appeared to have an unknown
amount of ram soldered to the motherboard. The unit has its ROM
stored on a separate removable card, in all of the units I have
heard mention of from other sources, the STB2 featured a special
ROM with an all red circuit board.
(Picture take from Applefritter)
This "Red ROM" had a stripped down version of the
Mac OS burned into it among other embedded goodies to deal with
the set top box functions. But the unit I had had a plain vanilla
green ROM card. The unit has a standard LC style power supply
unit and also has a circular mount for either a fan or a speaker,
the unit I had did not have anything in this mount. There were
solder wells on the board for a 20 pin floppy disk drive connector,
though there is no jack connected to this mount, it appears one
could be added by anyone with good soldering skills. The unit
also has an odd looking expansion card slot, it looks like an
LC PDS slot but is oriented in the wrong direction. The slot
has a plastic carrier secured to the board with a plastic screw,
apparently expansion cards were seated facing to the motherboard.
TESTS OF THE UNIT
I had heard that when the unit was plugged into a TV and turned
on, it would show a blue screen with the words APPLE in the center
when it did not find the TV service it was supposed to use. I
tried to plug the unit into a TV but got no response on the screen.
I also tried using the RCA jacks with the same results. Unfortunately
I could not test the S-Video connector because I do not have
an S-Video adapter. I had also been told that the STB2 could
be booted with a standard Mac system on a hard disk connected
to the HDI 30 SCSI port. I hooked up a Zip drive to the SCSI
port with a HDI 29 adapter cable, hooked a keyboard and mouse
to the ADB port, and attempted to boot the unit. This trick works
on Powerbooks, the Zip drive uses standard SCSI protocols and
the bootstrap loader will recognize the drive as a boot volume
without having to load any drivers, but it did not work on the
STB2. The power key on the keyboard activated the unit, but there
was no evidence of hard disk activity and the power indicator
remained red. Next I tried booting off of a 350 megabyte hard
disk loaded with a version of System 7.5. The unit accessed the
hard disk on startup, but only for a few seconds, and the STB2
did not draw anything to the screen. I next tried a 150 megabyte
hard disk loaded with System 7.0. The unit would check the hard
disk at startup, and again once every minute thereafter, but
it did not boot, and did not display anything to the screen.
I next tried using a 250 megabyte hard disk lifted from a Quadra
700, my reasoning being that since the Quadra had a 68040 processor,
it was the most LC 475 friendly system I could obtain without
lifting the hard drive from an LC 475. It did not work, the STB2
did not even attempt to boot the drive. All three of the hard
drives were set to SCSI id 0 and should have been terminated.
Next I tried starting up the unit while holding down Command-Option-T-V
while hooked up to the RCA ports, as I had heard suggested by
an owner of another STB, it had no effect. I tried zapping the
PRAM (Command-Option-T-V) with no effect. I tried resetting the
CUDA chip by holding down the button on the motherboard for several
seconds (At least I hope it is the CUDA reset) but this
had no effect. I tried removing the ROM and starting it up, hoping
that some board level functionality of the LC 475 series might
take over the boot process. There was no effect. I tried adding
a 16 megabyte 72 pin SIMM to the SIMM slot and booting. There
was no effect. At this point I had done everything I could have
possibly done, if this were an LC 475 I was trying to boot, and
I would assume the unit to have a fried motherboard.
Apple up to this point has made three different prototype
set top boxes, not including the Pippin game console. None of
these set top boxes ever went to market, for all of its research
Apple never sold a single unit. The first set top box, referred
to as the STB1 or the STB GREY, is pictured below
I have been unable to find any hard information on the unit,
what it was designed for, or how many were made, but the few
chance bits of information I have gathered suggest that it has
an internal floppy drive, an internal hard disk, and a 15 pin
monitor out port. There are some units on the market, and they
occasionally appear on ebay.
Here is a picture of the innards of the STB1. You can clearly
see the floppy drive secured to the top of the unit.
The STB2 was Apples second attempt at a set top box. The person
who sold me my STB2 also sold between ten and fifteen more units.
I managed to track down several of the people who had bought
the persons other units by scanning the applefritter forums.
I discovered several things from them. The green ROM is a Mask
ROM intended for production units. This suggests that the STB2
I have was one of the last ones made, and Apple must have pulled
the plug on the project right before the units went on sale,
if production ROMS were made. The other buyers of this persons
units were having the same amount of trouble getting them to
boot as I was, suggesting that this batch of STB2's was defective.
At the time this was written the STB3 was Apples last foray
into the set top box market. I have heard only that the STB3
was a mock-up unit made out of wood, and that no prototype was
actually built.
Given all this information I can think of only four things
that would cause the units failure.
1. The unit is defective.
2. The unit will not boot because the Mask ROM does not have
a bootstrap loader.
3. A special key combination (like the Cmd-Opt-t-v) or some
other trick is required to boot Mask ROM units.
4. The unit requires the remote to activate the boot function.
Syntax Error/:
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