Apple Computer Inc yesterday duly introduced its first three Power Macintoshes, with a rather misleading base price of $1,819, since the price excludes fairly important items such as a sceen and a keyboard. The three are the Power Macintosh 6100/60, 7100/66 and 8100/80, subscripts referring to the clock speed of the PowerPC 601 chip. Apple reckons it has over 150 software developers worldwide committed to shipping native PowerPC versions of their applications. Apple Business Systems also announced that it plans to introduce Apple Workgroup Servers based on the PowerPC in May. The $1,820 base price buys an 8Mb 6100/60 with 160Mb disk. Adding basic monitor and keyboard takes the price to $2,100. The 7100/66 is from $3,200 the 8100/80 from $4,500, rising to $6,160 for a system including 16Mb of memory and 2Mb of Video RAM. Apple also has PowerPC logic board and processor upgrades for current Macs, and a new Apple Multiple Scan 20 Display 20 two-page, colour Trinitron display, costing $2,150.