View Single Post
Old 28 June 2021, 01:15   #50
pandy71
Registered User
 
Join Date: Jun 2010
Location: PL?
Posts: 2,769
Quote:
Originally Posted by Toni Wilen View Post
256*25 (Genlock bit is settable and readable if RDRAM=1)

Other things I can think of that are much bigger in Lisa:

- 2 more bitplanes.
- Bitplane registers (I think it is 3 per plane) are 64-bit (was 16-bit)
- Sprite registers (4 per sprite) are 64-bit (was 16-bit)
- Palette registers probably are some kind of complex dual-ported design because they can be written to (or even read) by the CPU without visible glitches.
- "real" shres support, all horizontal comparators use shres timing internally. Denise was mostly lores based except bitplanes supported hires. But this shouldn't increase complexity much.
Thx Toni, i should check spec before asking.
Can't find now source but somebody listed that Lisa 391227-01 has over 225 thousand transistors - this mean it is most complex IC - it has more transistors than Agnus (Alice), + Paula + Denise + MC68000 - this is very odd to be honest unless HP process required something special then it is very difficult to justify such complexity.
pandy71 is offline  
 
Page generated in 0.06878 seconds with 11 queries