1200XL OS to 800XL OS

[walter_J64bit]

Can someone just burn the 800XL OS to an EPROM and just pop it in the 1200XL would that work or you have to make some mod to the 1200Xl and can the same to be done with MMU?

[charliecron]

Well you cant just pop it in, theres a couple wires to be moved around, 1 to be added, but it'll work. Not sure about the MMU. Instructions are here. I've done it, easy enough..

 

http://www.retrobits.net/atari/pbi.shtml

[+kheller2]

Can someone just burn the 800XL OS to an EPROM and just pop it in the 1200XL would that work or you have to make some mod to the 1200Xl and can the same to be done with MMU?

 

As charliecron mentioned, its a bit more involved. 1200XL has two 8K roms, the 600/800XL ROM is asingle 16K.

[walter_J64bit]

Hmmm , It might just be easier to keep the old 1200XL OS.

[Almost Rice]

Hmmm , It might just be easier to keep the old 1200XL OS.

 

Actually its not that hard. The instructions are straight forward. Also you might want to add the 5V to SIO and Chroma while you have the system open. The only other things I would consider that you need is in the future is Supervideo or Clearpic and the 256k ram.

[+Guitarman]

Can someone just burn the 800XL OS to an EPROM and just pop it in the 1200XL would that work or you have to make some mod to the 1200Xl and can the same to be done with MMU?

 

 

The MMU does need to be switched with a newer one (XL/XE) but it is just a swap. The 1200XL OS chips are 24pin and the XL/XE OS is 28pin but the board locations have 28pin ability. I have done this upgrade to all my 1200XL's (including adding Basic C) and greatly suggest it. If you have a prom burner, you can make the OS and Basic roms yourself. The MMU can be used from a parted XL/XE or you can get them from Best or B&C.