CompuServe Messages

Hi Kev, Never looked close enough at the 68340 to get to know the DMA controller. I was going to suggest it was probably similiar to the 68440 DDMAC, but this device only has two modes – Burst Transfer (block) and cycle steal without hold. The 68450 has a third mode, but I don't know what it is (XRM=11 is MC68450 reserved). Acording to MC68340/D, when request mode is internal, there are four adjustable bus bandwidths. If you have 32 bit bus built around the 16 bit interface on the 68340, the DMA module can sustain a transfer rate of 33.3 MBytes/second (doing DMA to/from a 32 bit device from/to 32 bit memory via 32 bit data bus), or if via 16 bit bus, 8.4 MBytes/second – no slouch! I would rather play with my 68332. Know where I can get some real high torque (and I mean high!) stepping motors cheap? Wouldn't mind replacing the rotors on the Az-El array. 73, Kelly