kh (10/26/82)
1) Can the basic 16K machine be later retro-fitted up to the "extended BASIC", or should I spend $100 more for that now? I understand the Extended gives better color graphics functions; is it worth $100 extra? Yes, it can be expanded later. And yes, it's definitely worth it to get extended basic. 2) Spec sheet sez the 6809E inside is clocked at 0.89 MHz. Seems slow; that chip is rated 2.0 MHz, right? The 68B09E is rated 2.0 MHz The 6809E is not, and there are other chips inside that also are not rated that high. You can double the clock speed in software, though this isn't guaranteed to work in all cases. For example, I/O will generally not work correctly, and the ROM cartridges usually won't work. I have heard that the Basic rom does switch speeds frequently, but I don't know for sure. (Replacing the two 6821's with 68A21's will usually solve most of the problems with high speed.) 3) What is their expansion buss like? Full 16-bit address? Easy to hook up home-brew hack cards to? It could be clean like the 6809, or did they hose it up like S100 did to the 8080? The expansion bus IS nice. Radio Shack publishes an understandable technical guide to the color computer which your local store should carry. It has all the relevant info. 4) How easily can I expand screen to 64--80 chars and LOWER CASE? (Yeah--buy some mem-map video board, right? Well, at least it need not have graphics!!!). 80-microcomputing has had articles on how to have lower case, and on many other hardware mods. If you do buy a CC, a subscription is probably a wise investment. See if you can get specific back issues somewhere locally. 5) Is the sound generator inside really limited to one tone at a time, at rather limited random pitches, or can it play 3+ genuine musical pitches at once? Someone here told me they use a genuine D-A converter, but it sounded like bad old square wave to me. There is a 6-bit D-A converter so you could write your own (assembly lang.) routines to get better sound. See technical manual for details. Generally, I would recommend Atari over Radio Shack for sound. The Commodore 64 also looks good (good price, too!), but quality has traditionally been a problem with any CBM machine. 6) How do you rate the BASIC and machine-code monitor? I DEFINITELY want to write machine code for a beatiful architecture like the 6809; wihtout machine code, I might as well use a Z80. Basic is Microsoft and very good (I'm talking extended basic). What machine-code monitor? There's none built in, but several companies make good ones. 6809 is definitely a step up from Z80. Too bad Radio Shack didn't build a machine that lived up to the power of the 6809. The design is obviously modified from an example by Motorola on how to inter- face the 6809 with the color graphics chip that the color computer uses. They added the keyboard and rs-232 interface and the cassette/sound/joystick interface and commissioned Microsoft to write a BASIC for it. Fortunately, there's room for escape with the expansion interface. PS--The analog (!) joystick, as used in the Missile Command (Polaris) game, is terrific. Also the BASIC can do File I/O to the casette, for us folks too poor to buy floppies. The analog joystick is definitely good for some uses, but for many (most?) games a self-centering one would be nice, and analog is usually not required. duke!unc!kh kh.unc@UDel-Relay
dce (10/26/82)
In addition to Kenny's information, let it be known that you can actually expand the Color Computer to 64K by bypassing the cartridge area. The Videtex cartridge is available for turning the computer into a terminal. You can also build a parallel interface for it. The list goes on and on... David Elliott