brs (03/28/83)
I am trying to compare the graphics support available for different inexpensive home computers. The requirements are cost around $500 providing high resolution (full TV) and graphics commands built into Basic. The desirable graphics commands might be grouped as follows: (A) point plotting, line drawing (B) drawing of other shapes such as arcs, circles, squares (C) transformations: translation, rotation, scaling (D) transformations on generated objects rather than rectangular regions (E) object manipulations: selection, handling overlaps (F) filling of regions with color (G) animation: small separately moving objects (sprites, player/missiles) (H) animation: flipping between entire screens or screen sections "sprites" are a form of E for limited-sized objects. Note that simulating transformations in Basic (rather than machine language) can rarely be done in real-time. In fact, hardware support is preferable. Preliminary research has produced the following. Please send corrections and additions to me and I will summarize for the Net. The first line gives a typical computer store price, RAM size, high-resolution points, high-resolution non-background colors. The second line describes the graphics commands available. Radio Shack Color Computer with extended Basic: $500, 32K, 256*192, 8 A, B, C, F, H Atari 800 with Programmer Kit $550, 48K, 320*192, 1 (3 by tricks) A, F, G Commodore 64 $400, 64K, 256*192, 4 (changable on an 8*8 character basis) A, F, G The above seem to be the only ones selling in quantity today (Vic 20 and TI 99/4a have character graphics only, Apple II is around $1100). I have heard rumors that Commodore and Atari may also have "extended Basic" cartridges (the former called VSP?) but have no details. Keyboard rankings are: Atari, Commodore, Radio Shack. All of the prices have just been cut dramatically. Promising others just available but only read about include: TI CC-40 (builtin 30 char display like Epson HX-20) $350, 48K, 256*192, 16 Timex Sinclair 2000 $200, 48K, 256*192, 8 Sanyo PHC25 $250, 48K, 256*192, 8
jsgray (03/29/83)
The TRS-80 Colour Computer supports only green/black or buff/black in high resolution (256X192) mode (not the 8 colours stated in the comparison). In the next best mode (128X192), you can use four different colours. To get 8 colours, you have to use very low resolution (something like 64X64). Despite the limited colour and resolution, it is still a good machine because it has an excellent BASIC, with a lot of graphics functions that other low-priced home computers lack. (Not that I like programming in BASIC... I tend to write M6809 assembler on it) Jan Gray ...watmath!jsgray