meuchen@grad1.cis.upenn.edu (Paul Eric Menchen) (07/18/90)
In article <1990Jul16.173822.6405@cs.swarthmore.edu> jackiw@cs.swarthmore.edu (Nick Jackiw) writes: >dan@sics.se (Dan Sahlin) writes: >> PS. Does anyone have any ideas how the dithering is performed in 32-bit >> Color Quickdraw? It seems to work very well, and I can display a dithered >> version of color pictures even on a black and white Mac SE/30. >> Unfortunately this feature is for some reason disabled on a Mac Plus. > >Color QuickDraw, and its 32-bit superset, are written in 68030 code. The >Mac plus is a 68000. The feature is not disabled; it is nonexistent. Not quite. 32 bit QuickDraw and Color QuickDraw run fine on my 68020 Mac II. When 32 bit QuickDraw attempts to load, it checks for Color QuickDraw first, which isn't in the Mac Plus ROMs. I think you can patch Color QuickDraw on the Plus and SE. This is my impression from Inside Mac V which discusses the "features of Color QuickDraw implemented for the Macintosh Plus, the Macintosh SE, and the Macintosh II ..." This part I'm not sure on, and a look at the tech notes may be in order. Paul Eric Menchen meuchen@grad1.cis.upenn.edu
minich@d.cs.okstate.edu (Robert Minich) (07/19/90)
by meuchen@grad1.cis.upenn.edu (Paul Eric Menchen): | jackiw@cs.swarthmore.edu (Nick Jackiw) writes: |>dan@sics.se (Dan Sahlin) writes: |>> PS. Does anyone have any ideas how the dithering is performed in 32-bit |>> Color Quickdraw? It seems to work very well, and I can display a dithered |>> version of color pictures even on a black and white Mac SE/30. |>> Unfortunately this feature is for some reason disabled on a Mac Plus. |> |>Color QuickDraw, and its 32-bit superset, are written in 68030 code. The |>Mac plus is a 68000. The feature is not disabled; it is nonexistent. | | Not quite. 32 bit QuickDraw and Color QuickDraw run fine on my 68020 | Mac II. When 32 bit QuickDraw attempts to load, it checks for Color | QuickDraw first, which isn't in the Mac Plus ROMs. I think you can | patch Color QuickDraw on the Plus and SE. This is my impression from | Inside Mac V which discusses the "features of Color QuickDraw | implemented for the Macintosh Plus, the Macintosh SE, and the | Macintosh II ..." This part I'm not sure on, and a look at the tech | notes may be in order. The part about "features of Color QuickDraw implemented for the Macintosh Plus, the Macintosh SE, and the Macintosh II ..." includes in its entirety: o Text drawing modes are enhanced, and now include a text mask mode, drawing with multibit fonts, and fractional character positioning. o The QuickDraw picture format (PICT) has been enhanced, and inculdes a number of new opcodes. ... So, Color QD is not reaaly implemented for 68000 Macs (Plus, SE, Portable and pre-Plus) except that classic QD won't choke on PICT's with color opcodes (it basically ignores color info), and can use multibit fonts (no doubt making 0=white and all_else=black). Patching Color QD to run on a 68000 would involve rewritting most of CQD since it takes advantage of features introduced with the 68020 (bitfields). Assuming you get past these barriers (or Apple does...), you then have to deal with the fact that the 68000 probably wont be able to make the speed acceptable and you'd need some sort of frame buffer. The SE might work out here but the Plus has no slots and the Portable has severe restrictions on power usage by add in cards. Side note: classic QD does support limited color (8 fixed colors, to be accurate) but most software doesn't use it since you need a Color QD Mac to view it. (Someone once made a hardware box that actually implemented this color model for 68000 macines, but it was slow and rather limited.) -- | _ /| | Robert Minich |Q: Why is the food so lousy, and | \'o.O' | Oklahoma State University |the service so bad? Time traveler: | =(___)= | minich@d.cs.okstate.edu |A:The waiters know in advance what | U | - Bill sez "Ackphtth" |kind of tip they'll be getting.