This file describes types of cartridge images supported by the Atari800
emulator.

There are:
- raw images - files that contain only dump of cartridge memory
- CART files - images with additional 16-byte header, which contains type
  of the cartridge

For raw images you usually have to select the cartridge type each time
you insert an image. To make it easier, you only select from types of same
image size. If there's only one supported type that matches file's length
(like there's for 4 KB cartridges), that type is selected automatically.

The advantage of using CART files is that you don't have to select
the cartridge type, because it is stored inside the file.

The CART format has been introduced in Atari800 0.8.0, when there were
only 4 supported cartridge types. The format has not changed, only new types
have been added.

The format is:
 first 4 bytes containing 'C' 'A' 'R' 'T'.
 next 4 bytes containing cartridge type in MSB format (see the table below).
 next 4 bytes containing cartridge checksum in MSB format (ROM only).
 next 4 bytes are currently unused (zero).
 followed immediately with the ROM data: 4, 8, 16, 32, 40, 64, 128, 256, 512
 or 1024 kilobytes.

The recommended file name extension for CART files is CAR.

Currently supported cartridge types:

+----+-----------+------+---------------------------------------------------+
| Id |  Machine  | Size | Name                                              |
|----+-----------+------+---------------------------------------------------+
|  1 | 800/XL/XE |    8 | Standard 8 KB cartridge                           |
|  2 | 800/XL/XE |   16 | Standard 16 KB cartridge                          |
|  3 | 800/XL/XE |   16 | OSS two chip 16 KB cartridge (034M)               |
|  4 |   5200    |   32 | Standard 32 KB 5200 cartridge                     |
|  5 | 800/XL/XE |   32 | DB 32 KB cartridge                                |
|  6 |   5200    |   16 | Two chip 16 KB 5200 cartridge                     |
|  7 |   5200    |   40 | Bounty Bob Strikes Back 40 KB 5200 cartridge      |
|  8 | 800/XL/XE |   64 | 64 KB Williams cartridge                          |
|  9 | 800/XL/XE |   64 | Express 64 KB cartridge                           |
| 10 | 800/XL/XE |   64 | Diamond 64 KB cartridge                           |
| 11 | 800/XL/XE |   64 | SpartaDOS X 64 KB cartridge                       |
| 12 | 800/XL/XE |   32 | XEGS 32 KB cartridge                              |
| 13 | 800/XL/XE |   64 | XEGS 64 KB cartridge                              |
| 14 | 800/XL/XE |  128 | XEGS 128 KB cartridge                             |
| 15 | 800/XL/XE |   16 | OSS one chip 16 KB cartridge                      |
| 16 |   5200    |   16 | One chip 16 KB 5200 cartridge                     |
| 17 | 800/XL/XE |  128 | Atrax 128 KB cartridge                            |
| 18 | 800/XL/XE |   40 | Bounty Bob Strikes Back 40 KB cartridge           |
| 19 |   5200    |    8 | Standard 8 KB 5200 cartridge                      |
| 20 |   5200    |    4 | Standard 4 KB 5200 cartridge                      |
| 21 |    800    |    8 | Right slot 8 KB cartridge                         |
| 22 | 800/XL/XE |   32 | 32 KB Williams cartridge                          |
| 23 | 800/XL/XE |  256 | XEGS 256 KB cartridge                             |
| 24 | 800/XL/XE |  512 | XEGS 512 KB cartridge                             |
| 25 | 800/XL/XE | 1024 | XEGS 1 MB cartridge                               |
| 26 | 800/XL/XE |   16 | MegaCart 16 KB cartridge                          |
| 27 | 800/XL/XE |   32 | MegaCart 32 KB cartridge                          |
| 28 | 800/XL/XE |   64 | MegaCart 64 KB cartridge                          |
| 29 | 800/XL/XE |  128 | MegaCart 128 KB cartridge                         |
| 30 | 800/XL/XE |  256 | MegaCart 256 KB cartridge                         |
| 31 | 800/XL/XE |  512 | MegaCart 512 KB cartridge                         |
| 32 | 800/XL/XE | 1024 | MegaCart 1 MB cartridge                           |
| 33 | 800/XL/XE |   32 | Switchable XEGS 32 KB cartridge                   |
| 34 | 800/XL/XE |   64 | Switchable XEGS 64 KB cartridge                   |
| 35 | 800/XL/XE |  128 | Switchable XEGS 128 KB cartridge                  |
| 36 | 800/XL/XE |  256 | Switchable XEGS 256 KB cartridge                  |
| 37 | 800/XL/XE |  512 | Switchable XEGS 512 KB cartridge                  |
| 38 | 800/XL/XE | 1024 | Switchable XEGS 1 MB cartridge                    |
| 39 | 800/XL/XE |    8 | Phoenix 8 KB cartridge                            |
| 40 | 800/XL/XE |   16 | Blizzard 16 KB cartridge                          |
| 41 | 800/XL/XE |  128 | Atarimax 128 KB Flash cartridge                   |
| 42 | 800/XL/XE | 1024 | Atarimax 1 MB Flash cartridge                     |
| 43 | 800/XL/XE |  128 | SpartaDOS X 128 KB cartridge                      |
| 44 | 800/XL/XE |    8 | OSS 8 KB cartridge                                |
| 45 | 800/XL/XE |   16 | OSS two chip 16 KB cartridge (043M)               |
| 46 | 800/XL/XE |    4 | Blizzard 4 KB cartridge                           |
| 47 | 800/XL/XE |   32 | AST 32 KB cartridge                               |
| 48 | 800/XL/XE |   64 | Atrax SDX 64 KB cartridge                         |
| 49 | 800/XL/XE |  128 | Atrax SDX 128 KB cartridge                        |
| 50 | 800/XL/XE |   64 | Turbosoft 64 KB cartridge                         |
| 51 | 800/XL/XE |  128 | Turbosoft 128 KB cartridge                        |
+----+-----------+------+---------------------------------------------------+

Id is the cartridge type code stored in the CART file.

Machine indicates if the cartridge is for Atari 8-bit Home Computers
(400/800 and XL/XE) or the Atari 5200 Game System.

Size is length of image in kilobytes.

Below are descriptions of all types. For bank-switched cartridges banks
are numbered in the order they appear in the image file, starting with 0.

+---------------------------------------------------------------------------+
| Type 1: Standard 8 KB cartridge                                           |
+---------------------------------------------------------------------------+

 Standard 8 KB cartridge, that occupies 8 KB of address space between $A000
 and $BFFF.

+---------------------------------------------------------------------------+
| Type 2: Standard 16 KB cartridge                                          |
+---------------------------------------------------------------------------+

 Standard 16 KB cartridge, that occupies 16 KB of address space between
 $8000 and $BFFF.

+---------------------------------------------------------------------------+
| Type 3: OSS two chip 16 KB cartridge (034M)                               |
+---------------------------------------------------------------------------+

 NOTE: This cartridge image format has been obsoleted by Type 45 because its
 order of banks is incorrect (i.e. the order in a physical cartridge's ROM
 chips is different). This format is still supported by the CART file format
 for backward compatibility.

 The cartridge occupies 8 KB of address space between $A000 and $BFFF. Its
 memory is divided into 4 banks, 4 KB each. Bank number 3 (the last one) is
 always mapped to $B000-$BFFF. Bank in $A000-$AFFF is selected by an access to
 $D500-$D5FF. Only 4 lowest bits of address are significant:
 - $D5x0 selects bank 0.
 - $D5x1 is not useful - it selects banks 0 and 1 (the bytes are binary AND of
   the corresponding bytes from banks 0 and 1).
 - $D5x3 or $D5x7 selects bank 1.
 - $D5x4 selects bank 2.
 - $D5x5 is not useful - it selects banks 1 and 2 (the bytes are binary AND of
   the corresponding bytes from banks 1 and 2).
 - $D5x2 or $D5x6 is not useful. It disables ROM (there are $FF bytes in
   $A000-$AFFF).
 - $D5x8-$D5xF disables whole cartridge (enables computer's memory in address
   space between $A000 and $BFFF).

+---------------------------------------------------------------------------+
| Type 4: Standard 32 KB 5200 cartridge                                     |
+---------------------------------------------------------------------------+

 Standard 32 KB cartridge for Atari 5200, that occupies 32 KB of address
 space between $4000 and $BFFF.

+---------------------------------------------------------------------------+
| Type 5: DB 32 KB cartridge                                                |
+---------------------------------------------------------------------------+

 A 32 KB bank-switched cartridge. There are 4 banks. Bank 3 is mapped to
 $A000-$BFFF. Bank in $8000-$9FFF is selected by an access to $D500-$D5FF.
 Two lowest bits of address select bank 0, 1, 2 or 3.

+---------------------------------------------------------------------------+
| Type 6: Two chip 16 KB 5200 cartridge                                     |
+---------------------------------------------------------------------------+

 In Atari 5200 there's 32 KB of address space reserved for the cartridge
 ($4000-$BFFF). A two chip 16 KB cartridge is mapped that way:
 - First 8 KB are mapped into lower 16 KB. Since an address line is not
   connected, $4000-$5FFF and $6000-$7FFF contain same data, which is first
   half of the cartridge image.
 - Similarly, second 8 KB are mapped into upper 16 KB.

+---------------------------------------------------------------------------+
| Type 7: Bounty Bob Strikes Back 40 KB 5200 cartridge                      |
+---------------------------------------------------------------------------+

 The cartridge with "Bounty Bob Strikes Back" game uses very strange
 bank switching method:
 - Four 4 KB banks (0,1,2,3) are mapped into $4000-$4FFF. An access to $4FF6
   selects bank 0, $4FF7 - bank 1, $4FF8 - bank 2, $4FF9 - bank 3.
 - Four 4 KB banks (4,5,6,7) are mapped into $5000-$5FFF. An access to $5FF6
   selects bank 4, $5FF7 - bank 5, $5FF8 - bank 6, $5FF9 - bank 7.
 - The remaining 8 KB is mapped to upper 16 KB of cartridge address space
   in Atari 5200. That is, $8000-$9FFF and $A000-$BFFF contain same data.

+---------------------------------------------------------------------------+
| Type 8: 64 KB Williams cartridge                                          |
+---------------------------------------------------------------------------+

 The cartridge has 8 banks mapped to $A000-$BFFF. An access to $D500 selects
 bank 0, $D501 - bank 1, etc. An access to $D508-$D50F disables
 the cartridge.

+---------------------------------------------------------------------------+
| Type 9: Express 64 KB cartridge                                           |
+---------------------------------------------------------------------------+

 The cartridge has 8 banks mapped to $A000-$BFFF. An access to $D577 selects
 bank 0, $D576 - bank 1, etc. An access to $D578-$D57F disables
 the cartridge.

+---------------------------------------------------------------------------+
| Type 10: Diamond 64 KB cartridge                                          |
+---------------------------------------------------------------------------+

 The cartridge has 8 banks mapped to $A000-$BFFF. An access to $D5D7 selects
 bank 0, $D5D6 - bank 1, etc. An access to $D5D8-$D5DF disables
 the cartridge.

+---------------------------------------------------------------------------+
| Type 11: SpartaDOS X 64 KB cartridge                                      |
+---------------------------------------------------------------------------+

 The cartridge has 8 banks mapped to $A000-$BFFF. It also contains an
 additional cartridge slot which allows to plug a second cartridge in.
 An access to $D5E7 selects bank 0, $D5E6 - bank 1, etc. down to $D5E0. An
 access to $D5E8-$D5EB disables the SDX cartridge and enables the second
 cartridge. An access to $D5EC-$D5EF disables both cartridges.
 Accesses to all addresses on page D5 always reaches the second cartridge,
 even if it is disabled by SpartaDOS or if the SpartaDOS cartridge itself is
 enabled.

+---------------------------------------------------------------------------+
| Type 12: XEGS 32 KB cartridge                                             |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 4 banks, 8 KB each.
 Bank 3 (the last one) is always mapped to $A000-$BFFF. Two lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF.

+---------------------------------------------------------------------------+
| Type 13: XEGS 64 KB cartridge                                             |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 8 banks, 8 KB each.
 Bank 7 (the last one) is always mapped to $A000-$BFFF. Three lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF.

+---------------------------------------------------------------------------+
| Type 14: XEGS 128 KB cartridge                                            |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 16 banks, 8 KB each.
 Bank 15 (the last one) is always mapped to $A000-$BFFF. Four lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF.

+---------------------------------------------------------------------------+
| Type 15: OSS one chip 16 KB cartridge                                     |
+---------------------------------------------------------------------------+

 There are two types of OSS 16KB cartridges; this is the later, simpler one.
 Used by BASIC XL 1.03, Action! 3.6, MAC/65 1.1 and BASIC XE 4.1 (and possibly
 also by later versions of the above software).
 It consists of one 16 KB ROM chip.
 The cartridge occupies 8 KB of address space between $A000 and $BFFF. Its
 memory is divided into 4 banks, 4 KB each. Bank number 0 (the first one) is
 always mapped to $B000-$BFFF. Bank in $A000-$AFFF is selected by an access to
 $D500-$D5FF. Only bits 0 and 3 of address are significant:
 - A3=0, A0=0 - selects bank 1
 - A3=0, A0=1 - selects bank 3
 - A3=1, A0=0 - disables cartridge (enables computer's memory in address space
   between $A000 and $BFFF)
 - A3=1, A0=1 - selects bank 2

+---------------------------------------------------------------------------+
| Type 16: One chip 16 KB 5200 cartridge                                    |
+---------------------------------------------------------------------------+

 16 KB cartridge for Atari 5200, that occupies 16 KB of address space
 between $8000 and $BFFF.

+---------------------------------------------------------------------------+
| Type 17: Atrax 128 KB cartridge                                           |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 8 KB of address space between $A000
 and $BFFF. The cartridge memory is divided into 16 banks, 8 KB each.
 If a byte written to $D500-$D5FF has highest bit set, the cartridge is
 disabled. Otherwise four lowest bits select the bank mapped to $A000-$BFFF.

+---------------------------------------------------------------------------+
| Type 18: Bounty Bob Strikes Back 40 KB cartridge                          |
+---------------------------------------------------------------------------+

 The cartridge with "Bounty Bob Strikes Back" game uses very strange
 bank switching method:
 - Four 4 KB banks (0,1,2,3) are mapped into $8000-$8FFF. An access to $8FF6
   selects bank 0, $8FF7 - bank 1, $8FF8 - bank 2, $8FF9 - bank 3.
 - Four 4 KB banks (4,5,6,7) are mapped into $9000-$9FFF. An access to $9FF6
   selects bank 4, $9FF7 - bank 5, $9FF8 - bank 6, $9FF9 - bank 7.
 - The remaining 8 KB is mapped to $A000-$BFFF.

+---------------------------------------------------------------------------+
| Type 19: Standard 8 KB 5200 cartridge                                     |
+---------------------------------------------------------------------------+

 Standard 8 KB cartridge for Atari 5200, mapped into $8000-$9FFF
 and $A000-$BFFF.

+---------------------------------------------------------------------------+
| Type 20: Standard 4 KB 5200 cartridge                                     |
+---------------------------------------------------------------------------+

 Standard 4 KB cartridge for Atari 5200, mapped into $8000-$8FFF,
 $9000-$9FFF, $A000-$AFFF and $B000-$BFFF.

+---------------------------------------------------------------------------+
| Type 21: Right slot 8 KB cartridge                                        |
+---------------------------------------------------------------------------+

 8 KB cartridge for Atari 800, mapped into $8000-$9FFF. Atari 800 was
 the only 8-bit Atari with a Right Cartridge slot, in addition
 to the Left Cartridge slot as present on all 8-bit Ataris.

+---------------------------------------------------------------------------+
| Type 22: 32 KB Williams cartridge                                         |
+---------------------------------------------------------------------------+

 The cartridge has 4 banks mapped to $A000-$BFFF. An access to $D500 selects
 bank 0, $D501 - bank 1, etc. An access to $D508-$D50F disables
 the cartridge.

+---------------------------------------------------------------------------+
| Type 23: XEGS 256 KB cartridge                                            |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 32 banks, 8 KB each.
 The last bank is always mapped to $A000-BFFF. Five lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF.

+---------------------------------------------------------------------------+
| Type 24: XEGS 512 KB cartridge                                            |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 64 banks, 8 KB each.
 The last bank is always mapped to $A000-$BFFF. Six lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF.

+---------------------------------------------------------------------------+
| Type 25: XEGS 1 MB cartridge                                              |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 128 banks, 8 KB each.
 The last bank is always mapped to $A000-$BFFF. Seven lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF.

+---------------------------------------------------------------------------+
| Type 26: MegaCart 16 KB cartridge                                         |
+---------------------------------------------------------------------------+

 A 16 KB cartridge, that occupies 16 KB of address space between $8000
 and $BFFF, and can be disabled by writing a byte with bit 7 set to
 $D500-$D5FF.

+---------------------------------------------------------------------------+
| Type 27: MegaCart 32 KB cartridge                                         |
+---------------------------------------------------------------------------+

 A bank-switched cartridge that occupies 16 KB of address space between
 $8000 and $BFFF. It is controlled by a byte written to $D500-$D5FF. Bit 0
 selects one of two available banks, bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 28: MegaCart 64 KB cartridge                                         |
+---------------------------------------------------------------------------+

 A bank-switched cartridge that occupies 16 KB of address space between
 $8000 and $BFFF. It is controlled by a byte written to $D500-$D5FF. Bits 0
 and 1 select one of four available banks, bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 29: MegaCart 128 KB cartridge                                        |
+---------------------------------------------------------------------------+

 A bank-switched cartridge that occupies 16 KB of address space between
 $8000 and $BFFF. It is controlled by a byte written to $D500-$D5FF.
 Bits 0,1,2 select one of 8 available banks, bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 30: MegaCart 256 KB cartridge                                        |
+---------------------------------------------------------------------------+

 A bank-switched cartridge that occupies 16 KB of address space between
 $8000 and $BFFF. It is controlled by a byte written to $D500-$D5FF. Four
 lowest bits select one of 16 available banks, bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 31: MegaCart 512 KB cartridge                                        |
+---------------------------------------------------------------------------+

 A bank-switched cartridge that occupies 16 KB of address space between
 $8000 and $BFFF. It is controlled by a byte written to $D500-$D5FF. Five
 lowest bits select one of 32 available banks, bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 32: MegaCart 1 MB cartridge                                          |
+---------------------------------------------------------------------------+

 A bank-switched cartridge that occupies 16 KB of address space between
 $8000 and $BFFF. It is controlled by a byte written to $D500-$D5FF. Six
 lowest bits select one of 64 available banks, bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 33: Switchable XEGS 32 KB cartridge                                  |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 4 banks, 8 KB each.
 Bank 3 (the last one) is always mapped to $A000-$BFFF. Two lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF,
 bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 34: Switchable XEGS 64 KB cartridge                                  |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 8 banks, 8 KB each.
 Bank 7 (the last one) is always mapped to $A000-$BFFF. Three lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF,
 bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 35: Switchable XEGS 128 KB cartridge                                 |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 16 banks, 8 KB each.
 Bank 15 (the last one) is always mapped to $A000-$BFFF. Four lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF,
 bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 36: Switchable XEGS 256 KB cartridge                                 |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 32 banks, 8 KB each.
 The last bank is always mapped to $A000-$BFFF. Five lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF,
 bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 37: Switchable XEGS 512 KB cartridge                                 |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 64 banks, 8 KB each.
 The last bank is always mapped to $A000-$BFFF. Six lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF,
 bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 38: Switchable XEGS 1 MB cartridge                                   |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 16 KB of address space between $8000
 and $BFFF. The cartridge memory is divided into 128 banks, 8 KB each.
 The last bank is always mapped to $A000-$BFFF. Seven lowest bits of
 a byte written to $D500-$D5FF select the bank mapped to $8000-$BFFF,
 bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 39: Phoenix 8 KB cartridge                                           |
+---------------------------------------------------------------------------+

 A 8 KB cartridge, that occupies 8 KB of address space between $A000
 and $BFFF. It starts in enabled state and can be disabled by an access to
 $D500-$D5FF. Re-enabling is possible only by turning the computer off and on.
 Some units contain a RESET button that allows to enable the cartridge without
 touching the power button.

+---------------------------------------------------------------------------+
| Type 40: Blizzard 16 KB cartridge                                         |
+---------------------------------------------------------------------------+

 A 16 KB cartridge, that occupies 16 KB of address space between $8000
 and $BFFF. It starts in enabled state and can be disabled by an access to
 $D500-$D5FF. Re-enabling is possible only by turning the computer off and on.
 Some units contain a RESET button that allows to enable the cartridge without
 touching the power button.

+---------------------------------------------------------------------------+
| Type 41: Atarimax 128 KB Flash cartridge                                  |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 8 KB of address space between $A000
 and $BFFF. The cartridge memory is divided into 16 banks, 8 KB each.
 The 4 lowest bits of the address written to $D500-$D50F select the bank
 mapped to $A000-$BFFF. Writing to $D510-$D51F disables the cartridge
 and any write to $D520-$D5FF is ignored.

+---------------------------------------------------------------------------+
| Type 42: Atarimax 1 MB Flash cartridge                                    |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 8 KB of address space between $A000
 and $BFFF. The cartridge memory is divided into 128 banks, 8 KB each.
 The seven lowest bits of the address written to $D500-$D57F select the bank
 mapped to $A000-$BFFF, bit 7 disables the cartridge.

+---------------------------------------------------------------------------+
| Type 43: SpartaDOS X 128 KB cartridge                                     |
+---------------------------------------------------------------------------+

 The cartridge has 16 banks mapped to $A000-$BFFF. It also contains an
 additional cartridge slot which allows to plug a second cartridge in. First
 8 banks are selected by an access to $D5F7-$D5F0, the other 8 banks by an
 access to $D5E7-$D5E0. An access to $D5E8-$D5EB or $D5F8-$D5FB disables the
 SDX cartridge and enables the second cartridge. An access to $D5EC-$D5EF or
 $D5FC-$D5FF disables both cartriges.
 Accesses to all addresses on page D5 always reaches the second cartridge,
 even if it is disabled by SpartaDOS or if the SpartaDOS cartridge itself is
 enabled.

+---------------------------------------------------------------------------+
| Type 44: OSS 8 KB cartridge                                               |
+---------------------------------------------------------------------------+

 Used in The Writer's Tool cartridge, it is actually an OSS one chip cartridge
 board (see Type 15) with an 8 KB ROM chip instead of a normal 16 KB one.
 The cartridge occupies 8 KB of address space between $A000 and $BFFF. Its
 memory is divided into 2 banks, 4 KB each. Bank number 0 (the first one) is
 always mapped to $B000-$BFFF. Bank in $A000-$AFFF is selected by an access to
 $D500-$D5FF. Only bits 0 and 3 of address are significant:
 - A3=0, A0=0 or 1 - selects bank 1
 - A3=1, A0=0 - disables cartridge (enables computer's memory in address space
   between $A000 and $BFFF)
 - A3=1, A0=1 - selects bank 0

Reference: http://www.retrobits.net/atari/osshack.shtml

+---------------------------------------------------------------------------+
| Type 45: OSS two chip 16 KB cartridge (043M)                              |
+---------------------------------------------------------------------------+

 There are two types of OSS 16KB cartridges; this is the earlier, more
 complicated one. Used by BASIC XL 1.02 and earlier, Action! 3.5 and earlier,
 and MAC/65 1.0. It consists of two 8 KB ROM chips.
 The cartridge occupies 8 KB of address space between $A000 and $BFFF. Its
 memory is divided into 4 banks, 4 KB each. Bank number 3 (the last one) is
 always mapped to $B000-$BFFF. Bank in $A000-$AFFF is selected by an access to
 $D500-$D5FF. Only 4 lowest bits of address are significant:
 - $D5x0 selects bank 0.
 - $D5x1 is not useful - it selects banks 0 and 2 (the bytes are binary AND of
   the corresponding bytes from banks 0 and 2).
 - $D5x3 or $D5x7 selects bank 2.
 - $D5x4 selects bank 1.
 - $D5x5 is not useful - it selects banks 1 and 2 (the bytes are binary AND of
   the corresponding bytes from banks 1 and 2).
 - $D5x2 or $D5x6 is not useful. It disables ROM (there are $FF bytes in
   $A000-$AFFF).
 - $D5x8-$D5xF disables whole cartridge (enables computer's memory in address
   space between $A000 and $BFFF).

 Reference: http://www.retrobits.net/atari/osscarts.shtml

+---------------------------------------------------------------------------+
| Type 46: Blizzard 4 KB cartridge                                          |
+---------------------------------------------------------------------------+

 A 4 KB cartridge, that occupies 8 KB of address space between $A000
 and $BFFF. Line A12 is unconnected, so the cartridge's memory is duplicated
 in $A000-$AFFF and $B000-$BFFF. The cartridge starts in enabled state and can
 be disabled by an access to $D500-$D5FF. Re-enabling is possible only by
 turning the computer off and on. Some units contain a RESET button that
 allows to enable the cartridge without touching the power button.

 Reference: http://www.serious-dial.atari.pl/Serious/S13/A18.html

+---------------------------------------------------------------------------+
| Type 47: AST 32 KB cartridge                                              |
+---------------------------------------------------------------------------+

 This cartridge occupies 8 KB of address space between $A000 and $BFFF. The
 cartridge memory is divided into 128 banks, 256 B each. On power on, bank 0
 is visible in $A000-$BFFF (repeated 32 times) and also in $D500-$D5FF. A
 write operation to $D500-$D5FF disables the cartridge (freeing the
 $A000-$BFFF area) and selects the next 256-byte bank visible at $D500-$D5FF.
 After bank 31 the write operation selects bank 0 again.

 Reference: http://www.atari.org.pl/forum/viewtopic.php?pid=134014#p134014

+---------------------------------------------------------------------------+
| Type 48: Atrax SDX 64 KB cartridge                                        |
+---------------------------------------------------------------------------+

 A variant of Type 11: SpartaDOS X 64 KB cartridge. The banking scheme is
 identical, but the address and data lines between the cartridge port and the
 ROM chip are interleaved as follows:
   (Left - cartridge port + bank select lines, right - EPROM pins)
    A0 -  A6
    A1 -  A7
    A2 - A12
    A3 - A15
    A4 - A14
    A5 - A13
    A6 -  A8
    A7 -  A5
    A8 -  A4
    A9 -  A3
   A10 -  A0
   A11 -  A1
   A12 -  A2
   A13 -  A9  \
   A14 - A11   > bank select
   A15 - A10  /
    D0 -  Q4
    D1 -  Q0
    D2 -  Q5
    D3 -  Q1
    D4 -  Q7
    D5 -  Q6
    D6 -  Q3
    D7 -  Q2
 By deinterleaving a ROM image, one would get a normal image of type 11.
 See Type 11 for details on the banking scheme.

 Reference: http://www.dereatari.republika.pl/atarisch/sparta.zip

+---------------------------------------------------------------------------+
| Type 49: Atrax SDX 128 KB cartridge                                       |
+---------------------------------------------------------------------------+

 A variant of Type 43: SpartaDOS X 128 KB cartridge. The banking scheme is
 identical, but the address and data lines between the cartridge port and the
 ROM chip are interleaved. The interleaving is similar to that of Type 48,
 but with added A16 line, so it looks as follows:
   (Left - cartridge port + bank select lines, right - EPROM pins)
    A0 -  A6
    A1 -  A7
    A2 - A12
    A3 - A15
    A4 - A14
    A5 - A13
    A6 -  A8
    A7 -  A5
    A8 -  A4
    A9 -  A3
   A10 -  A0
   A11 -  A1
   A12 -  A2
   A13 -  A9   \
   A14 - A11    > bank select
   A15 - A10   /
   A16 - A16  /
    D0 -  Q4
    D1 -  Q0
    D2 -  Q5
    D3 -  Q1
    D4 -  Q7
    D5 -  Q6
    D6 -  Q3
    D7 -  Q2
 By deinterleaving a ROM image, one would get a normal image of type 43.
 See Type 43 for details on the banking scheme.

 Reference: http://www.dereatari.republika.pl/atarisch/sparta.zip
            http://trub.atari8.info/index.php?ref=atrax_128

+---------------------------------------------------------------------------+
| Type 50: Turbosoft 64 KB cartridge                                        |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 8 KB of address space between $A000
 and $BFFF. The cartridge memory is divided into 8 banks, 8 KB each. Banks
 are selected by an access to an address at $D500-$D5FF. Bits 0-2 of the
 address select the bank mapped to $A000-$BFFF. Bit 4 disables the cartridge
 and enables RAM. Bits 3, 6 and 7 are ignored. The cartridge starts with
 bank 0 enabled.

 Reference: http://www.retrogames.cl/turbosoft.html

+---------------------------------------------------------------------------+
| Type 51: Turbosoft 128 KB cartridge                                       |
+---------------------------------------------------------------------------+

 This bank-switched cartridge occupies 8 KB of address space between $A000
 and $BFFF. The cartridge memory is divided into 16 banks, 8 KB each. Banks
 are selected by an access to an address at $D500-D5FF. Bits 0-3 of the
 address select the bank mapped to $A000-$BFFF. Bit 4 disables the cartridge
 and enables RAM. Bits 6 and 7 are ignored. The cartridge starts with bank
 0 enabled.

 Reference: http://www.retrogames.cl/turbosoft.html
