I was web surfing last night - I should have been programming my prop :-(
Anyway, I was thinking that for the PropAltair and similar emulations, that ram is always the problem. So, I thought about using 2 props as follows...
One prop would be the standard prop running VGA (or TV) and keyboard (and maybe mouse) and Serial (FullDuplex) and running a terminal emulation (VT52, VT100, etc). This is basically what OBC has done with PropComm (without the propdos). Nothing complex here. It can communicate serially to another prop. It may also use the SD card as a disk emulation to the second prop.
The second prop would have a serial connection to the first prop, and would load from eeprom as normal. It would then boot the emulation or load from the other prop. This prop would have its io pins connected directly to a 128Kx8 sram. This takes 17 pins for address, 8 for data and 3 for ce, oe and we, totalling 28 pins. This plus the 2 serial and 2 I2C makes the total 32 io pins the prop has. The sram has 10-15nS, so the prop will be slower than this.
Would a pcb with just the second prop built like this sound interesting, or should a pcb have both props on it including vga, tv, keyboard, mouse, etc?
Links to other interesting threads:
· Prop Tools under Development or Completed (Index)
· Emulators (Micros eg Altair, and Terminals eg VT100) - index
My cruising website is ·www.bluemagic.biz
Post Edited (Cluso99) : 1/22/2009 9:47:40 AM GMT