Commodore 64: Virgin Tape loader

@DrWatson

Published in 

C64 tape formats

 · 18 May 2021

Found on...

• Aaargh!
• Action Force
• Barry McGuigan Boxing
• Dan Dare 2
• Double Dragon 2
• E-Swat
• Erebus
• FA Cup Football
• Guardian 2
• Line of Fire
• Manic Miner
• Motorbike Madness
• Shogun

Future Bike ? (hmm, thres = $016E on this one, need raw dump)

 Threshold : $15E (350) clock cycles (TAP byte = $2C). 
 Bit 0 : $21 
 Bit 1 : $3B 
 Endianess : MSbF 
 Pilot : $AA (*256) 
 Sync : $A0  

 1 byte : Block Number (they start at 0) 
 1 byte : VIC screen hide/show, value is $00 or $10, ($10 = show) 
 2 bytes : Load Address (low,high) 
 2 bytes : End Address (low,high). 
 2 bytes : Execution Address (if $0000 then no action taken) 
 n bytes : Data. 
 1 byte : Checksum (0 xor all n data bytes) 
 

Note : The same format can be found in 'Hi-Tec Tape' but with higher threshold.