Date   : Wed, 11 May 2005 12:31:18 +0100
From   : Richard Gellman <splodge@...>
Subject: Re: Beeb versus Master?

Acting defence for the Master 128 Party....

Sprow wrote:

>>There was no actual sprite plotting code in any of the OS versions.
>>    
>>
>
>Yes there is - MOS 3.00 onwards contains sprite plotting code (move and copy
>block) as well as all the other handy extra VDU code like circle plotting
>and flood fills. Yum.
>  
>
Not quite sprite plotting though. Granted, those functions were very 
useful to have in ROM, but they weren't actual sprite plotting 
functions, like those provided by the SPRITER ROM (which, incidentally, 
operates identically to a subset of the Sprite calls in Risc OS).

>Back to the original question though both machines have selling points
>BBC B 
> - has motherboard speech sockets of course (whereas the Master needed a 
>   custom cartridge)
>  
>
Excepting the case of Speech! by Superior Software, of course (and its 
implementation in many Superior titles. All done through the standard 
sound chip.)

> - keyboard doesn't break every few months like the crappy Master ones
>  
>
Its not the keyboard so much as its connectors. My M128 keyboard has 
been fine for years, but I do accept that repeated in-and-out of the 
keyboard will snap the ribbons eventually (cheap plastic/strip 
conductors, as opposed to the webbed wires in the B).

>Master
> - a 1770 disc controller
> - a numeric keypad
> - stacks more RAM (so page is at &E00)
> - space for internal co processor
> - CMOS/real time clock for configuration settings
>  
>
Complete avec bug du millenium :)

>and I'm sure the subjective list could go on....
>Sprow.
>
>  
>
Just to add a few subtle extras to Sprow's list, the M128 has a few 
extra custom chips inside, notably the memory controller and I/O 
controller. These actually make the system operate indentical to the BBC 
B (excepting memory map differences of course), but package up the 
demultiplexors and logic chips into two 40-pin ICs. Couple these to the 
improved SERPROC and VIDPROC chips, and the whole thing runs at a 
slightly lower power consumption :)

On the downside, the M128 has less socket space for ROMs. Sockets 9 to 
15 are virtual, in effect, and actually map through to the MOS ROM chip, 
providing DFS, BASIC, ADFS, Edit, View, ViewSheet, and TERMINAL. So 
these can't be unplugged/swapped out.

Sockets 4, 5, 6, and 7 by default facilitate the sideways RAM. You can 
swap these in banks of 2 for a single socket on the board. e.g. 4 + 5 
can be replaced by a ROM, and 6 + 7 can be replaced by another ROM. 
links changing required.

ROM socket 8 is available on the board, and this plus the two above make 
up the three empty sockets on a standard M128. Sockets 0,1,2,3 map in 
twos to the catridge sockets. 0 + 1 = socket 0, 2 + 3 = socket 1.

-- Richard