hacktv:analogcable:gi_boxes

GI/Jerrold boxes, general info

The information on this page applies to most Jerrold and General Instrument boxes, with some differences between models.

:!: If you have more information on these (e.g. installation/service manuals for the set-top boxes, or details on the meaning of the F key diagnostic functions), please email: philpem@gmail.com

+----------+
|  1   2   |
|   -A  -B |
+----------+

This mode permits the monitoring of the descrambler circuit, the FM receiver and the FM signal.

  • Digit 1: State of the descrambler
    • C = Clear channel
    • S = Scrambled channel
    • b = Barker channel
    • - = Disconnected
  • Digit 2: State of FM Receiver
    • O = FM Data being received “OK”
    • E = FM Data stream error
  • Indicator 1: on when the converter sees a purchasable event
  • Indicator 2: on when the converter is addressed over the FM data stream

This will show nine digits of serial number information, followed by two digits of firmware version information (on CFT-2100).

  • 0n: Place of Manufacture?
    • n=0: Japan
    • n=1: Taiwan
    • n=2: Taiwan (?)
  • 1n: Year of manufacture
    • n=last digit of year of manufacture e.g. 1991=1
  • 2n: Month of manufacture
    • 20: Jan
    • 21: February
    • 22: March
    • 23: April
    • 24: May
    • 25: June
    • 26: July
    • 27: August
    • 28: September
    • 29: October
    • 2A: November
    • 2B: December
  • 4n through 9n: serial number digits (per serial number label)
  • 11th and 12th numbers: firmware versions (as per F 3)

The serial number is also on the barcode label on the bottom of the box. Letters are converted to digits as follows:

Barcode 0 1 2 3 4 5 6 7 8 9 A B C D E F G H J K L M
Number 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 A B

Serial number after a RAM clear or battery failure

According to this post by Mixmaster, after the RAM is cleared, the serial number will reset to all 'F'.

Reported as showing the following:

  • i: Internal firmware
  • r: Expansion ROM version

CFT2100 boxes display the following alternating:

  • r0
  • h6
  • Digit 1: State of FSK data
    • R: receiving data
    • -: idle
    • T: transmitting data (two-way units only)
  • Digit 2: Data Parity/Checksum
    • O = Data “OK”
    • E = Data “ERROR”

Alternating display of frequency and level :?:

There are 16 different levels, 0-9, A-F.

:!: Note – both boxes I have display 0 / '83 alternating, for all channels and RF input powers.

Reported in this post by RFslacker to be the return frequency and level the box is set to transmit on, for 2-way boxes only.

Toggles clock on and off

:!: Note – seems to do nothing on CFT2100

  • E0: Normal
  • E1: Reset timeout, or good FM packet not received
    • If the Timer Mode = ON, then this error indicates the converter has not received a Reset Time-out command.
    • If the Timer Mode = OFF, then this error indicates the converter has not received a good FM packet.
  • E2: not used
  • E3: not used
  • E4: Illegal terminal. The set-top failed the Legal Terminal test.
  • E5: Default address. The set-top contains the default address due to a Clear Address command.
  • E6: not used
  • E7: The set-top has a faulty or wrong (defeat attempt) ROM installed or an incorrect initialization procedure.
  • E8: Site code error: The set-top is installed in a system for which it is not initialized (wrong site code).
  • E9: Invalid serial number: Bad checksum pattern in non-volatile memory
  • EA: The set-top has a faulty RAM or a dead battery.
    • This error occurs if the battery fails to keep the RAM alive during a power down. The error causes the set-top to disconnect and its barker channel to be set at 106.5 MHz.
    • Initialize the set-top to clear the error. If the error persists, the unit is in need of repair.

From http://cd.textfiles.com/group42/HACK/TV/CABLE/CABLE.HTM

 __ __ __ __ - __ __ __
 |  |  |  |    |  |  |
 |  |  |  |    |  |  |___ T = two-way capability, C = PROM programmable
 |  |  |  |    |  |
 |  |  |  |    |  |______ DI = Inband decoder, DO = Outband decoder,  
 |  |  |  |    |          PC = Single pay channel, A = Addressable
 |  |  |  |    |
 |  |  |  |    |_________ Output channel number (3 very common)
 |  |  |  |    
 |  |  |  |______________ D or I = tri-mode system, N = parental lockout   
 |  |  |                    feature (6 dB-only systems are "blank" here)
 |  |  |
 |  |  |_________________ M = mid-band only, X = thru 400 MHz,
 |  |                     Z = thru 450 MHz, BB = baseband
 |  |   
 |  |____________________ S = Set-top, R = Remote
 | 
 |_______________________ D = Digital tuning, J = Analog tuning
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  • Last modified: 2023/01/05 18:02
  • by philpem