binder@dosadi.DEC (The Stainless Steel Rat) (07/02/84)
I don't recall the requestor, but someone was looking for a raster
graphics controller chip - the NEC uPD7220 Graphics Display Controller
may be a candidate. Some of its features are these:
1. uP interface, does DMA with 8257/8237 controllers.
2. Interfaces up to 256K 16-bit words of display memory, 4M pixels.
3. Light pen input, external video synch input.
4. 1024x1024 display, four planes of colour or grey scale; two in-
dependently scrollable areas. 1 to 16x zoom. Panning.
Cheers,
Dick Binder (The Stainless Steel Rat)
UUCP: { decvax, allegra, ucbvax }!decwrl!dec-rhea!dec-dosadi!binder
ARPA: binder%dosadi.DEC@decwrl.ARPA
Posted Monday 2nd July 1984, 10:52 EDT by DOSADI::BINDERken@turtlevax.UUCP (Ken Turkowski) (07/03/84)
The NEC 7220 is a real dog to interface to (but then again, "software
doesn't cost anything" ...). I would instead recommend the Hitachi
63484, which has a 16-bit interface, and has clipping. It generates a
variety of graphic primitives, runs "quickly" without "snow mode", and
handles up to 4K x 4K x 16 frame stores.
--
Ken Turkowski @ CADLINC, Palo Alto, CA
UUCP: {amd,decwrl,dual,flairvax}!turtlevax!ken
--
Ken Turkowski @ CADLINC, Palo Alto, CA
UUCP: {amd,decwrl,dual,flairvax}!turtlevax!kenjcp@BRL-TGR.ARPA (07/07/84)
From: Joe Pistritto <jcp@BRL-TGR.ARPA> Keep in mind that the 7220 is SLOW!!!! I have experience witht he Heurikon MLZ-VDC multibus graphics board, which uses a 7220 as its mind, and it takes noticable times to do stuff like fill rectangles, (never mind complex shapes, etc). It is an order of magnitude slower than the raster graphic boxes I am used to, (such as the Lexidata 3400, Ramtek, etc.) Just be advised what you're getting yourself into in terms of performance. -JCP-
BILLW@SRI-KL.ARPA (07/07/84)
I would assume that the 7220 is slow as described only when using the built in commands to do graphics (NEC claims 800ns per pixel, which isnt bad for drawing lines, but isnt good for filling large rectangles). If you dula port your memory, then the processor can do bitblt type operations directly on the graphics memory, which ought to speed things up... BillW