I will post the service manual I found online here in hopes that it will help others out with their 2600 issues. This was the most up-to-date revision I could find and covers all known 2600 revisions.
Supercharger Tape Format Specification Tone Specifications: The Supercharger uses 2 distinct frequencies to store its data: A low frequency for a 1 bit and a high frequency for a 0 bit. To clarify this, let me state that the wavelength of the 0 bit is shorter than that of a 1 bit. The specific frequencies of the tones are not important as long as they are distinct enough to be distinguished by the Supercharger. To the Supercharger, each sinewave is a data bit. In the remaining text, I will refer to the tones as simply 'zero bit' and 'one bit' and any 'bytes' mentioned represent the 8 bits or tones that correspond to the byte's value. Now getting on with the actual format of the tape: Tape Format: Section: Header Tone Contents: Series of alternating 1 bits and 0 bits.
The end of the header tone is marked by two 0 bits. The header tone should last for a minimum of about 1 second. Example:.10100 Section: Data Header Contents: byte # -1 2 3Description -Start Address Lo-Byte Start Address Hi-Byte Control Byte This is the control byte, it determines the bankswitching mode of the SC.
Bits -D7-D5 D4-D2Function -Write Pulse Delay (Set to 0) RAM/ROM Configuration Value -000 001 010 011 100 101 110 1114$f000 -3 1 3 1 3 2 3 2$f800 -ROM ROM 1 3 ROM ROM 2 3# of pages to load (1 page = 256 bytes)5Data Header Checksum The 8 bytes in the Data Header must add up to #$55 (hex).6Multi-load byteTitles you can't find anywhere elseTry Scribd FREE for 30 days to access over 125 million titles without ads or interruptions! Start Free Trial Cancel Anytime.Titles you can't find anywhere elseTry Scribd FREE for 30 days to access over 125 million titles without ads or interruptions! Start Free Trial Cancel Anytime.Zero for single-load games.
For Multi-Load games you need to know what value the game is looking for. For Supercharger 8448 byte files this value is contained in the file. 7Lo-byte Bar Speed byte This is the lo-byte of the speed at which the bars move across the screen upon loading the game. Supercharger Fastload uses #$42.8Hi-byte Bar Speed byte This is the hi-byte of the speed at which the bars move across the screen upon loading the game. Supercharger Fastload uses #$02.Section: Page Header Contents: byte # Description - -1 Bank Byte - Tells Supercharger where to load the current page (256 bytes) into. This is determined as follows: Bank Byte Bits:7 6 5 4 3 2 1 0 / / Page # Bank #For example, a page loaded into bank 3, page 4 would have a page # of 000100 and a bank # of 11, combining these together you get 00010010 for a Bank Byte of #$13.
The simple formula to calculate the Bank Byte is: (Page #. 4) + Bank # 2Page Checksum - This byte is equal to: #$55 - (sum of all 256 bytes in page)Section: Data Page Contents: 256 bytes of data. The Page Header and Data Page sections are repeated for each page in the file to be loaded. Section: Footer Tone Contents: Series of alternating 1 bits and 0 bits. The footer tone should be about 1 second long.