On 04/19/2012 02:17 PM, Steve Gray wrote: > 2. It does share peripherals and the bitmap graphics modes are mostly > the same Multicolor Bitmap is not quite the same as with the VIC-II. As a bonus TED got you more colors, a hardware cursor, hardware blinking and hardware reverse mode. > 3. Sound is much like the VIC. Remember originally the TED series was a > low-end machine to compete with the $99 Sinclair ZX-81. I think the competitor was the ZX spectrum. Compared to the video and audio circuit of the spectrum, TED was still better. In case you don't know it, sound in the spectrum is done with the CPU by flipping a single port bit. About the simplest sound hardware possible. > In stead of making the TED perhaps commodore should have updated the VIC > to 80 columns.... That would have meant a complete redesign of the memory controller and bus interface. Remember, the original VIC was only able to do 22 or so chars per line in color with the affordable memory back then. And even that was only possible since it had the extra 4 data lines for the color RAM. To be able to get 40 chars per line in color from this memory speed with the VIC-II meant to add internal 40 x 12 memory for char pointers and color information and the famous badline per character row to grab fill that memory. TED has only 8 bit to do everything, that meant 2 badlines per character row already. As a bonus you get more colors. If you need a second badline, why use only 16 colors, you have 8 Bits for attributes now. The only way Commodore would have been able to get 80 chars per line would have been to double the memory access speed (with 150ns DRAM you can do a complete RAS/CAS-Cycle every 260ns) and since video and CPU are using the same bus alternatively, also double the CPU speed. Or implement page mode. Also you'd need a faster char ROM. > Since most of the work is in the TED the machine is quite simple. With > 60k+ free memory for BASIC it makes a nice system to learn programming > on. I like the case and keyboard. I have to say I prefer the C16 over the Plus/4. The Plus/4 keyboard never agreed with me and they get flaky with age. :( Gerrit Message was sent through the cbm-hackers mailing listReceived on 2012-04-19 16:00:05
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