Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!mcvax!ukc!stc!idec!camcon!anc From: anc@camcon.co.uk (Adrian Cockcroft) Newsgroups: comp.sys.amiga,comp.graphics Subject: PC2 Graphics beats Amiga Message-ID: <500@titan.camcon.co.uk> Date: Fri, 24-Apr-87 11:46:54 EDT Article-I.D.: titan.500 Posted: Fri Apr 24 11:46:54 1987 Date-Received: Thu, 30-Apr-87 02:33:59 EDT Organization: Cambridge Consultants Ltd., Cambridge, UK Lines: 62 Keywords: PC2 PS2 Amiga 82786 Xref: mnetor comp.sys.amiga:4231 comp.graphics:566 NB This is a second attempt at posting news and is the first real attempt at generating outgoing news from this site! The new IBM PC2 range was described in the Guardian computer pages on 9/4/87. Based on this information and other background info the PC2 graphics will be substantially better than the Amiga. They will also be substantially more expensive! All models use the Inmos IMSG171 colour lookup table, this has 256 entries and 6 bit DACs per colour giving 18 bits or 256K possible colours. Recent press announced a multi million pound order for these between IBM and Inmos. This supports 8 bits per pixel or 8 bitplanes. The low end PC2's seem to have a gate array that generates video timing to give noninterlaced 640 by 480 at 70 Hz refresh. Due to memory limitations this resolution is at most 4 bits per pixel. At 320 by 240 a full 8 bits per pixel can be generated. The memory is encoded as packed pixels in bytes rather than multiple bitplanes. All drawing is done in software. Summary vs Amiga: better to look at (no flicker, more colours) but much slower. The high end PC2's have a plug in card with 1 Meg of video ram and use the intel 82786 graphics chip. These machines are 80286 and 80386 based. I am using the Intel 82786 on a 68010 based prototype machine at the moment (together with Inmos G170) and it is very fast. It supports windowing in hardware with different windows having different bits per pixel including zero (zero BPP = 1 colour, takes no ram). This is done by fetching data for the video shift register from all over the place on the fly. It also has a drawing processor that includes a BITBLT (2.5 MPixels/s) fill area (30 Mpixels/s) lines, polylines and circles (2 MPixels/s) and CHARBLT at 20000 characters/s (given an ascii string and a font up to 16*16 pixels per char defined per character to give proportional spacing and kerning in hardware). The drawing processor is given a program to execute of graphics instructions which can be any size with unconditional jumps and subroutine call/return embedded. The CPU is told when the drawing processor has finished. All this is faster than the Amiga but the price for hires monitor + extra graphics RAM card will be about $2000. For those who want a 68010 (8MHz) + 82786 + G170 + (512K or 2Meg) + floppies + SCSI winchester + parallel & serial ports + Inmos C012 transputer link adapter that runs Tripos or OS/9 the Micro Concepts Image-10 is available. The Tripos is NOT from Metacomco, it is a much improved Cambridge University version. The hardware is available, Tripos and OS/9 are up and running but the Tripos 82786 windowing graphics drivers are not finished yet. 82786 configured for 768 by 576 50Hz interlaced PAL compatible timings. Cost is about 2000 pounds for twin floppy (720K each) or 2800 pounds for 20Mb winny+floppy (512K RAM). This doesnt include a monitor or software. A cheap (500 pounds) genlocking frame grabber will be ready soon. Contact Micro Concepts 2 St Stephens Road, Cheltenham, Gloucestershire, England. (0242) 510525. I spend my spare (!) time working on the Tripos graphics software for this machine and it has no involvement with Cambridge Consultants Ltd.