nas-2

N2-kbd

This is actually a new machine to me! It’s only taken me over 25 years to finally get one…  And then it’s like buses – 3 come along together (more or less).  😉

The NASCOM-2 has quite a lot of enhancements over the NASCOM-1:

  • Faster processor
  • Greater RAM/EPROM capacity on board
  • Built-in processor buffering to drive the Nas-bus directly
  • 8k Microsoft BASIC on board
  • Switchable start address on power-up/reset
  • Keyboard extended to include cursor + graphic keys
  • Improved NAS-SYS 1 monitor (in a single 2k ROM)
  • 300/1200 baud Kansas City tape interface
  • All graphic characters available from keyboard

The major advantage was that this computer could be equipped with enough on-board RAM to use it as a fully self-contained computer without the need for a bus system. The switchable start address allowed the system to boot up into BASIC if required, almost identically to the Tandy Level II computer. This made for a much more popular machine – especially when pre-assembled boards were offered for sale.

Almost all the extra bits that were necessary for a NASCOM-1 system were already present here. However, it is notable that NASCOM still required the user to wire a suitable relay (and driver transistor if necessary) to control the cassette deck. As almost all these systems used such a circuit it seems a strange omission.

The big increase in capability on the same PCB size (8in x 12in) was achieved in two ways. First, the workspace and video RAM was fitted as two 1k x 8 static RAM ICs instead of 16 1k X 1 devices. Secondly, much of the I/O and address decoding was achieved by replacing TTL logic with four PROMs.

 

 

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2 Responses to “Nascom-2”


  1. 1 KEN SMITH 09/11/2012 at 3:26 pm

    I HAVE A WORKING NASCOM 2 WITH DUAL FLOPPY DD, GRAPHICS CARD, PIO CARD FREE TO A GOOD HOME. ANY TAKERS?

  2. 2 KEN SMITH 04/12/2012 at 12:31 pm

    From Ken Smith
    A good home has now been found for the Nascom 2.
    See the blog http://nascom-uk.blogspot.co.uk/


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