Difference between revisions of "Sega Channel"

From MegaDrive Wiki
Jump to: navigation, search
(Added some technical schits)
m (7 revisions imported)
 
(5 intermediate revisions by the same user not shown)
Line 1: Line 1:
 
{{Template:PageStub}}
 
{{Template:PageStub}}
  
 +
{{AddonInfoBox
 +
| accessoryimage=SegaChannelAdaptorFrontSA.jpg
 +
| imgwidth=310
 +
| accessoryprogramscreen=
 +
| title=
 +
| maker=Sega, Scientific Atlanta, General Instrument
 +
| madefor=[[Mega Drive]]
 +
| alsoworks=
 +
| romsize=
 +
| sounddriver=GEMS
 +
| romsize = 256KB
 +
}}
 
The Sega Channel was a service offered by Sega between December 1994 to mid 1998. It the user to download various games, which changed on a monthly basis.
 
The Sega Channel was a service offered by Sega between December 1994 to mid 1998. It the user to download various games, which changed on a monthly basis.
  
Line 6: Line 18:
 
The Sega Channel signal originated in Denver, CO. It was carried over the Galaxy 7 satellite, located 91.0 degrees W longitude using transponder 1 with horizontal polarisation. The uplink signal was at a carrier frequency of 1.435 GHz and occupied 8 MHz bandwidth using QPSK modulation. The downlink signal was at a frequency of 1.1 GHz and occupied 6 MHz bandwidth using QPSK.
 
The Sega Channel signal originated in Denver, CO. It was carried over the Galaxy 7 satellite, located 91.0 degrees W longitude using transponder 1 with horizontal polarisation. The uplink signal was at a carrier frequency of 1.435 GHz and occupied 8 MHz bandwidth using QPSK modulation. The downlink signal was at a frequency of 1.1 GHz and occupied 6 MHz bandwidth using QPSK.
  
Subscriber Loop
+
===Subscriber Loop===
 
* occupied two 3 MHz non-contiguous channels
 
* occupied two 3 MHz non-contiguous channels
 
* data rate was 6 Mbit/s
 
* data rate was 6 Mbit/s
Line 13: Line 25:
 
* used Quadrature Partial Response (QPR) modulation
 
* used Quadrature Partial Response (QPR) modulation
  
QPR is a modulation scheme that uses a controlled inter-symbol interference. The receiver is capable of logically decoding the signal. QPR provides 20% better bandwidth performance than QPSK with only a minor increase in signal power. This Sega Channel adapter allowed the customer to download the game selected in less than 1 minute. The adapter contained 4 MB [[DRAM|DRAM,]] which held a game of up to 32 megabits (or 4 megabytes) in size. Once the game was downloaded, it worked exactly as if it were a cartridge. Sega also had ratings for each game and supplied the parents with a password (4 digit pin number) if so desired.
+
QPR is a modulation scheme that uses a controlled inter-symbol interference. The receiver is capable of logically decoding the signal. QPR provides 20% better bandwidth performance than QPSK with only a minor increase in signal power.
 +
 
 +
This Sega Channel adapter allowed the customer to download the game selected in less than 1 minute. The adapter contained 4 Megabytes of [[DRAM|DRAM,]] which held games of up to 32 megabits (or 4 megabytes) in size. Once the game was downloaded, it worked exactly as if it were a cartridge, but all saved data and the game itself was lost when the unit was turned off. Sega also had ratings for each game and supplied the parents with a password (4 digit pin number) if so desired.
 +
 
 +
[[Category:Hardware]]

Latest revision as of 11:29, 16 March 2015

This short article is in need of work. You can help us by adding to it.


310px

Fast Facts on the Sega Channel

Made By: Sega, Scientific Atlanta, General Instrument
Made For: Mega Drive
Size of Program ROM: 256KB

The Sega Channel was a service offered by Sega between December 1994 to mid 1998. It the user to download various games, which changed on a monthly basis.

Technical information

The Sega Channel signal originated in Denver, CO. It was carried over the Galaxy 7 satellite, located 91.0 degrees W longitude using transponder 1 with horizontal polarisation. The uplink signal was at a carrier frequency of 1.435 GHz and occupied 8 MHz bandwidth using QPSK modulation. The downlink signal was at a frequency of 1.1 GHz and occupied 6 MHz bandwidth using QPSK.

Subscriber Loop

  • occupied two 3 MHz non-contiguous channels
  • data rate was 6 Mbit/s
  • tunable to 68 different operating frequencies between 51 and 118 MHz
  • Bit error ratio was <10E-06
  • used Quadrature Partial Response (QPR) modulation

QPR is a modulation scheme that uses a controlled inter-symbol interference. The receiver is capable of logically decoding the signal. QPR provides 20% better bandwidth performance than QPSK with only a minor increase in signal power.

This Sega Channel adapter allowed the customer to download the game selected in less than 1 minute. The adapter contained 4 Megabytes of DRAM, which held games of up to 32 megabits (or 4 megabytes) in size. Once the game was downloaded, it worked exactly as if it were a cartridge, but all saved data and the game itself was lost when the unit was turned off. Sega also had ratings for each game and supplied the parents with a password (4 digit pin number) if so desired.