The Atari 1450XLD Computer System

The Flagship Atari Computer

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      The Atari 1450XLD computer system.   This was to be the flagship of the "Next Generation" of Atari computers.   The term Next Generation is a little inappropriate.   Even though the new 1400XL and the 1450XLD would bring a new look and new features to the aging Atari 8-bit line, they were still using the same 6502c, the same chipset and no other really radical enhancements.

      Not to put a damper on such a fine product, the 1450XLD may have not had a newer 16bit CPU or faster clock speed.   What it did have was a new addition to the Atari chipset (which comprised the ANTIC, GTIA, POKEY and PIA).   The new chip was called "FREDDIE" and what this little chip could have done was something that was sorely needed.   Freddie was an MMU (Memory Management Unit), this new chip would have allowed BOTH the CPU and the ANTIC chip to independantly access different areas of memory for their own use.   What did this mean for the user?   It meant that a 1450XLD with a 1090XL expansion box containing one or more of the 64K memory modules would allow the CPU to access memory for programs (up to 64K) and the ANTIC could access up to 8K or more if needed to display graphics.   This meant that programmers would have more freedom and flexibility in writing programs that could have had more complex commands, better graphics and enough memory to accomplish what they had in mind.

     The next enhancement of the 1450XLD was its built in 300 baud modem.   Atari from the start saw that computers would one day all be tied to central information systems and to each other and thought that it was important to include a modem in its computers.  (Unfortunately Atari never included software that could upload and download until Atari Corp released SX-Express).

    The 1450XLD also had a built in voice synthesiser to allow the user to write speech easily into their programs, by using the V: handler, users to have their programs speak, adding a new dimension to interactive computer use.

    The final enhancement of the 1450XLD was it parallel disk drive controller interface and the inclusion of a 360K double density disk drive (a 2nd drive could be added at an authorized Atari service center)  The parallel disk interface is much faster then the SIO interface of all the other Atari computers and would allow for up to 100K per second data transfers.   However the disk interface proved to be unreliable and difficult to design and expensive since it required a PAL (Programmable Array Logic) which acted almost like a CPU itelf.   This was because the disk drive could only deliver data at slow speeds and the disk drive itself was only spinning at 300 RPM.  

   Hard drives spin at 3600 RPM and faster, most hard drives have a data buffer built into their onboard controller, disk drives do not so the parallel bus interface would look for the next piece of data from the disk drive, the disk could not access the data quick enough and the process would time out.   Atari had to design a PAL to control the flow of data to and from the disk drive to keep time outs from failing, this was an expensive solution.

   The original Atari 1450XLD motherboards known as the "TONG" motherboard were HUGE and contained an onboard disk drive controller as well as a prototyping area and several ROM sockets which are rumored to have been either for foreign language sets for the voice synthesiser or for Apple ][e emulation ROMs.   No one has ever been able to confirm or deny these rumors.   It is believed that due to the disk drive controller problems, Atari had created a new short board 1450XLD motherboard with NO disk drive controller onboard, it would instead be a daughter card which would be sold and installed at a later time at an authorized Atari service center.   The 1450XLD's would be sold as 1450XL's and when the user wanted the disk drive upgrade, they would bring their Atari 1450XL to an Authorized Atari service center and have the disk controller and one or two disk drives installed.   This would make the PC seem more expandable to the customer and would have generated high volumes of upgrades for service centers and Atari to cash in on.

    The 1450XLD is a beautiful machine with an ominously powerful look and feel.   Its disk drives are fast and although in todays world, the modem is useless, its nice to know the feature is there.   The monotone robotic sounding voice synthesizer is primitive by todays realistic true voice .WAV files, but it too is a pleasant feature to have built in.   The 1450XLD is a machine all Atari users wish was released, perhaps it would have made a little more of a difference if it and the 1090XL had been released.  Unfortunately, well never know...