Expert cartridge loader
=======================
  info by Fabrizio Gennari <fabrizio.ge@tiscalinet.it>

Used by the Trilogic Expert cartridge to save freezed games. Also some commercial games (Eye of Horus...) use it

Encoding:
---------

 Threshold: $141 (321) clock cycles
 Bit 0: TAP byte $1F
 Bit 1: TAP byte $33

Data Endianess: MOST Significant bit First

 Lead-In Byte :  $0F
 Sync sequence:  $0E, $0D, $0C, $0B, $0A, $09, $08, $07, $06, $05, $04, $03, $02, $01, $00

Structure:
----------

  The length of the block is calculated from Start and End address, which is
written at the start of the block (after the SYNC Byte):

 00 Start Address of data (Low, High byte)
 02 End   Address of data (Low, High byte)
 04 Data
 05 Checksum (sum of the Data bytes + 1 for each Data byte, modulo $100 (256))

