Atari XL Series Computers - 1400XL  

Technical Documents

SW Implementation of Parallel Devices May 22, 1984

Atari 1400XL Product Spec



Detailed confidential document on the design and feature specifications for the 1400XL Computer System


Atari Speech Handler ERS
Detailed confidential document on the device handler program to control the speech synthesizer in the Atari 1400 and 1450 computer systems


Atari 1400 Telecommunicator
Atari 1400/1450 Modem
Detailed confidential technical documentation of the design and implementation of the Atari 1400 Telecommunicator modem cartridge for use with the Voltrax SC01 Speech

Synthesizer chip (1450XLD's used SC02 chip, not compatible) and implementation of the internal Parallel Bus Interface modem in the Atari 1400/1450 computers


Atari 1400XL PAL's Detailed document containing the PAL chip decoding and the Equations for the 1400XL PAL A, B and C chips.


1400XL Schematics Full set of all 8 Sheets of the Atari 1400XL Computer Schematics.


In an effort to preserve the ROM code to
 any of Atari's unreleased and sometimes
one of a kind products, the actual
code is being put up onto the site for
all to study, examine and preserve.



Atari 1400XL Stand ALone Test ROM
Atari 1400XL Telecommunicator Talking
Terminal Program ROM

NEVER use a standard XL/XE power supply on a 1400XL

You will damage the voice chip and the GTIA.  Above is a

photo from a 1400XL power supply.  You can use a standard

PC power supply and build you own cable to connect to your

1400XL to power it.



The Atari 1400XL Computer System

     Model #'s: 1201XL, 1200XLS, 1400XL

     Codename: (No Codename Known)



 The Atari 600XL and 800XL were both welcomed by the Atari computer community. They provided many new features and an expansion path that Atari's computers needed.   In June of 1983 Atari would follow up from the announcements of the 600XL and 800XL with its other computers.   Originally called the Atari 1201XL and the 1250XL these new systems would be renamed the Atari 1400XL and the 1450XLD.

The 1400XL system featured all the standard features of the Atari 800XL, but also included several new enhancements. The first was the inclusion of the new custom chip called FREDDIE which handled bank switching functions and would give the new system the ability to handle memory more effectively.

 The FREDDIE allowed the ANTIC chip to access separate memory from the regular 64K of the XL system which meant that the system could display more colors and more complex displays of graphics without sacrificing the memory available for the programs to run.  

The next new enhancement was the inclusion of a SC-01 speech synthesizer chip and modifications to the OS to allow for a V: handler for VOICE.   Included with the new system was a cartridge called The 1400XL Telecommunicator which utitlized the voice synthesizer to announce changes in the configuration of the terminal program such as baud rate, line feeds, wrap around and so on.  

The last feature which was given away by the note of the cartridge was a built-in 300 BAUD modem.   This is my option was a bad decision.  Atari had the right idea in seeing that tele-computing was definitely the way of the future, but was still playing the "We'll sell them a closed box and if they want more features next year they'll have to run out a buy a whole new one".   What Atari should have done was make the modem a slide in module which could have been removed and replaced with a 300-1200 modem or faster as time went by or simply added a built-in RS-232c port to allow users to plug in their own choice of modems such as the ever popular Hayes modems.    As a point of interest to collectors; the original 1400XL's that were made have motherboards which actually say 1400 on them, later on Atari opted to create a universal 1400/1450 motherboard called the 1450XL which has a power connector and PBI daughter-card connector on it for the addition of disk drives.  

The idea was to make a single motherboard for both the 1400XL and for the 1450XL's which would have the daughter card installed with a disk drive.    The best non-enhancement was the fact that Atari went back to using the Atari 1200XL type casing again along with that wonderful keyboard. The 1400XL was meant to be the direct replacement for the 1200XL which was released at the beginning of 1983, but its expansion bus and OS were not ready yet so it was shipped without Expansion.   The 1400XL (originally the 1201XL) was to be the 1200XL's replacement.  However it had added features and a higher cost, so it became the 1400XL and Atari's 800XL was to be the 1200XL direct replacement in a much more affordable design at $299 versus the 1200XL price of $899.





Are you a former Atari engineer?  Did you work on the 1400XL or have direct knowledge of this project? 

Please contact the Atari Museum:  CLICK HERE