The chip, which was to be announced in September at 400MHz, 450MHz and 500MHz clock speeds, has been pushed back about a month to late October or possibly early November, the sources said. Intel officials confirmed the later launch, but would not commit to a firm date. The Mobile Pentium III will debut sometime after the Microprocessor Forum, which runs October 5-8, but before Comdex Fall, which starts November 15, said Intel spokesman Seth Walker. Walker, however, maintained that the chip has always been due later in the second half of this year. "It's always been second half. It's still second half," he said. Intel last June admitted to running into roadblocks with its Coppermine design, on which the Mobile Pentium III chip will be based, which have kept Pentium IIIs from performing at 600MHz and higher clock speeds. The California chip maker told PC makers in June that it would push back the introduction of a Coppermine-based desktop Pentium III until November, while it tweaked the design to gain greater performance. That chip also was supposed to run at 600MHz. Intel delivered this week a 600MHz Pentium III, but on its .25 micron manufacturing process. "The challenge is getting the design to run at the full frequency," Intel spokesman Howard High told PC Week in June. He also said in June that the first mobile Pentium III chip would ship in September. In the past two weeks, however, that schedule has been altered to be more in line with the launch date of desktop Pentium III chips, sources said. It is now likely that all of the Coppermine chips will be announced at the same time. The delay dismays some PC makers, who worry that product introductions late in the year may fall on deaf ears in the corporate market. Corporations, who are currently finalising Year 2000 preparations, may not have time to qualify systems with the new chip until after the New Year. Meanwhile, Intel, which maintains that the chip is due in the second half of the year, expects "strong second half sales," Walker said. The mobile Pentium III originally was supposed to debut in September at 450MHz, 500MHz and 600MHz, but the company revised those expectations in June. While it intended to ship the 500MHz in September, the 600MHz mobile Pentium III, which employs Geyserville Technology, was pushed back to the end of the year. Geyserville is technology that reduces the chip's clock speed and therefore power consumption while on battery power to extend battery life. The 600MHz mobile Pentium III with Geyserville Technology is now not expected until the first quarter of 2000. While Intel is grappling with Coppermine, it is moving ahead with other technologies and September will still see several product launches. The company will announce new chip sets and accompanying chips. They include the long-awaited 820 chipset, which offers support for Rambus Direct RAM, 4X Accelerated Graphics Port and a 133MHz memory bus. Two new Pentium III chips, a 600MHz and a 533MHz, will be launched to support the higher bus speed. At the same time, Intel will also announce the 810E a version of its 810 chipset for Pentium III-based PCs. It is likely that the 533MHz/810E based PCs will fall in at about $1,200 (£732). PCs using the 600MHz and 810E and 600MHz and 820 will be closer to $1500 and $2,000, sources said. Intel is also still on track to deliver a mobile Celeron chip running at 433MHz next month, however, sources said. Take me to the Pentium III Special.