Re: 6502 emulation update

[Charlie Springer <RAM@regnirps.com>]

On Wed, 3 Jan 2007 22:41:48 -0800, RedskullDC wrote
(in article <Mk1nh.1143$A8.139@news-server.bigpond.net.au>):

> $200 seems pretty expensive.
> 
> Have you checked out the ARM boards/modules at www.futurlec.com ?
> 
> For example: http://www.futurlec.com/ET-ARM_Stamp.shtml
> Includes Philips LPC2119 Microcontroller with 128kb Internal Flash Program 
> Memory
> . 16/32 Bit Operation with a speed of up to 58.9824MHz
> . Direct In-Circuit Program Download with RS-232 Connection
> . Up to 46 I/O points
> . 4 Channel 10-Bit A/D Converters
> . 2 CAN Interfaces with Acceptance Filters
> . 2 UARTS and Fast I2C, together with SPI
> . Two 32-Bit Timers with Four Capture and Compare Channels
> . On-Board Real-Time Clock
> . Power LED with Load and Reset Button
> . Easy to Install and Remove
> . Ideal as an Interchangeable Controller for Real-Time Systems
> 
> For $24.90 US .

Yes, these look good. The $200 was for an ARM9 at 200 MHz with 8 meg of fast 
RAM and 32 meg of FLASH.

An ARM7 setup can be very inexpensive. I have seen chips at $3.05.

On the other hand, the ARM9's tend to need external RAM and FLASH and a full 
speed ARM9 needs 32 bit data paths. The less expensive ones use 16 bit data 
paths because they expect people to use the Thumb instruction set. I prefer 
the ARM set with conditional execution of any instruction. The conditional 
execution bit was axed for the Thumb which squeezes many instructons down to 
16 bits. But you still need to load 32 bit data which needs two reads unless 
you use the high pin count versions with 32 bit paths.

-- Charlie Springer