Date   : Tue, 14 Jun 2005 22:43:03 +0100 (BST)
From   : BBC Micro <b_b_c_m_i_c_r_o@...>
Subject: Re: Issue 4 BBC B's

This might be off topic but wasn't it the ULA in the
Electron that caused its delay to market? Ferranti
were having problems with the ULA dont know what the
problems were exactly... 
!Maybe some guy with the letraset making the mask! 


--- Andrew Benham <adsb@...> wrote:

> Mike Tomlinson wrote:
> 
> > The Video ULA was also changed
> > from a Ferranti chip requiring a heatsink to a
> VLSI unit, which didn't
> > need a heatsink, at about the same time.
> 
> I'm really glad that semi-custom IC technology has
> moved on, because
> "ULA" is a lousy piece of terminology.
> It stands for "Uncommitted Logic Array", which is an
> accurate name until
> the last few steps in the manufacturing process. 
> These steps take the
> uncommitted "sea of gates" and, by adding an
> interconnect layer of metal
> according to the specification of the customer, turn
> it into a custom IC.
> 
> Whilst uncommitted (which is the only time that it's
> actually a ULA) it
> is of no use (it's rather like an unprogrammed ROM)
> - other than it has
> the potential to become useful.
> 
> So, to the pedant, the terms "Video ULA" and "Serial
> ULA" are wrong - 
> because the Logic Array can't be Uncommitted at this
> point - it's been
> committed to a customer's specification.
> 
> -- 
> Andrew Benham         adsb@...
> Southgate, London N14, United Kingdom
> 
> The gates in my computer are AND OR and NOT, not
> "Bill"
> 
> 



               
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