We have sold the Wizztronics 256K Ram bare Upgrade board PCB to Atari 800XL owners for about 14+ years now.  Using this Wizztronics 256K upgrade board, you can Pump up your Stock Atari 800XL computer to 256K of usable Ram Disk Storage.

 The bare Wizztronics 256K upgrade board, requires a double sided 16 pin header (Blue) for easy installation.  For Atari 800XL computers that have the CO21697 Antic Chip you will require 3 TTL chip installation pictured to the left.  If you have the 800XL CO12296 Antic Chip you will have to install 2 additional TTL chips (74LS158($.35) + 74LS373($.75), on the board.

Depending on your exact Atari 800XL configuration, you might have to install (unsolder and solder in 9), 16 Pin I.C. Sockets) for the required 8, 256K ram chips and Installation board 16 pin Header.  You will have also unsolder and lift 7 pins on the Pokey chip so you can attach the ribbon cable.

Supplied:  1 Bare Wizztronics 800XL 256K upgrade board, with installation instructions.

Extra Items required:  16 / 16 Pin double header $2.50, 1 each TTL 74LS139($.39), 74LS153($.35) and 74LS158 from the 800XL motherboard and one 33 ohm resistor from the 800XL motherboard. 

Not Supplied:  The Atari 5 1/4 Ram Disk Software to drive the Upgraded 800XL Ram, Solder,  I.C. Sockets, Extra TTL chips if required, short 5 conductor Ribbon Cable, short length of hook up wire and 41256 ($2.00 each) Ram Chips.  Most items are available Thru Best Electronics.

Required:  The ability to Unsolder and Solder in Components, The ability to read a Component layout Print.

Without the 800XL Ram Disk Software, the upgraded 256K Atari 800XL computer will act like an Stock Atari 64K computer.  The only Stock Atari 8 bit software that will access the 800XL upgraded 256K Ram, are Atari Stock programs that can normally Access the Atari 130XE extra Ram banks, like Atariwriter Plus Word Processor program.