lotus

previous page: 2.1) What are the memory limits of the various Acorn machines?
  
page up: ARM (Acorn Risc Machine) FAQ
  
next page: 2.3) Can PC VGA & Multisync Monitors be added to an Acorn machine?

2.2) What is a second processor and what second processors are there?




Description

This article is from the comp.sys.acorn FAQ, by Paul Vigay with numerous contributions by others.

2.2) What is a second processor and what second processors are there?

A second processor was the generic name for a range of parasite processors that could be linked to Acorn's original 8 bit machines via what was called the `Tube` interface. Basically the host machine became dedicated to handling the Input and Output while the second processor would do the higher level functions (like running your programs). The second processor ran asynchronously to the host processor allowing incredible increases in execution speed for programs. A wide range of processors were supported t his way allowing Acorn's eight bit range of machines to remain viable and useful for much longer than their technology would suggest.

The Second Processors that existed are :-

Z80 second processor.
6 MHz RAM.
64k Memory.
CP/M OS.
External second processor for all eight bit machines.
  
* 6502 second processor.
3 MHz RAM.
64k Memory.
Extended version of the BBC MOS.
External processor for all eight bit machines.
  
32016 second processor.
6 MHz RAM.
256k-4096k Memory.
Panos.
External processor for all eight bit machines.
  
ARM 1 second processor.
4 MHz RAM. (At a guess...)
4096k Memory.
Brazil OS.
External processor for all eight bit machines.
  
6502 co-processor. (internal second processor)
4 MHz RAM.
64k Memory.
Extended version of BBC MOS.
Internal processor for Master 128 machines but could be fitted external to the other eight bit machines.
  
80186 co-processor.
10 MHz RAM.
512k Memory.
DR-DOS+ with GEM.
Internal processor for Master 128 machines but could be fitted external to the other eight bit machines.

 

Continue to:













TOP
previous page: 2.1) What are the memory limits of the various Acorn machines?
  
page up: ARM (Acorn Risc Machine) FAQ
  
next page: 2.3) Can PC VGA & Multisync Monitors be added to an Acorn machine?