[comp.sys.m68k] Texas Instruments 34061FNL Video Processor

steveh@tasman.cc.utas.edu.au (Steven Howell) (05/10/91)

	Due to the excellent success i had with my request on the 
Zilog SCC chip, i decided to post again concerning another piece
of hardware that we wish to employ.

	We have currently designed a Video Graphics Circuit based
around the Intel 82786 VCP as the core. But to our suprise, local  
suppliers have discontinued this chip, and Intel informed me that
they are no longer manufacturing this chip. 

	So i had a quick flick through our Co-Processor manuals to 
see whats avail. I found a TMS34061FNL IC claiming it was capable
of delivering high qual displays and has the ability to manage its 
own memory. Has anyone had any dealing with this chip.
Could they give me some feed back on what it is like in performance
and ability to program. Would it be considered capable of producing
640x480 in 256 colours, with its own bit map memory.


thanks in advance 

steveh

stevenw@disk.uucp (Steven Weller) (05/15/91)

[ Stuff on the Intel 82786 and TMS 34061 graphics chips omitted ]

It does not surprise me that the 82786 chip was discontinued.  It was
very slow, due mainly to the quad porting of the graphics memory.

The 34061 is pretty good.  It is a video controller designed for
driving VRAMs.  It does all the timing for video and memory accesses
but does not draw a thing - that's up to the CPU.

One disadvantage is that each scan line uses a multiple of 2**n
pixels (or bytes, I cannot remember).  This is a result of the use
of VRAM I think, and means that you can end up needing much more
memory than you would expect for certain display sizes.


Steve

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