On average, there is one new software package written for the IBM Personal Computer every day IBM's original PC - the 5150 - had been the machine that spawned a whole new era of generic, dull and identi-kit computers which ended up trouncing everything that had gone before. However, this was not so much to do with IBM itself, but more because its 5150 was built from off-the-shelf parts, and the BIOS was easy enough to reverse-engineer - first in the Columbus PC and more famously by Compaq - which meant that all sorts of clone manufactures quickly piled in. Seven years had passed since the Commodore PET - the first recognisably-modern "personal computer" - had launched, and hundreds of different machines had come and gone in its wake, especially with the home-computer explosion of 1981-1984, but it wasn't too long before the IBM interpretation of the "PC" pushed almost everything else out of the way. IBM was however slow off the mark in Europe, allowing companies like Sirius/ACT to do well for a while in the business market, until the 5150 found its way to the other side of the Atlantic in 1982. The follow up was the XT - reportedly targetted at the Sirius - and then the AT. All these machines did well in banks and corporates, if not in the wider market, and came to also define the legions of clones that followed them. IBM seemed to implicitly acknowledge that its buyers were safe and steady corporate types who "never got fired for buying an IBM" and so seldom seemed to directly advertise particular machines, rather it concentrated on maintaining its name in the market. This was exemplified with this sort of advert (which is an amalgam of a three-page spread), featuring the "Charlie Chaplin" motif that ran for several years, which extoled the virtue of how much software was available for the IBM PC. In reality, it was software - availability, consistency and compatibility - that allowed the IBM PC to reign supreme. For the first time, users could buy a machine and know that packages they had used before would not only work on any PC, but that their purchases would most likely work on the next PC they bought. IBM was also very slow to develop its PC once it had actually launched it, and it really needed some developing as the original came with a feeble 64K - no more than many "toy" home computers at the time. This was becoming quite a limiting factor when running serious business applications, many of which were rapidly getting bigger and more demanding. To overcome this, early machines did a lot of memory paging - saving and reading memory from disk, but the low specification also meant that software writers had to cope with 64K as a lowest common denominator. The situation was also made worse by the fact that IBM's earliest PC was floppy-disk only, which only made paging slower - four to ten seconds to get a response by some accounts[source: "PC Passé", Personal Computer World, December 1984, p.98]. By the time the AT came out in 1983, IBM seemed to have learned from the limitations of the 5150. By now, a hard disk was standard and IBM's AT came with Intel's 80286, which ran three times faster than the 8088. That's a significant leap in performance: for a machine to go three times faster in 2024 would be like upgrading from a 4GHz CPU to a 12GHz one overnight. Much like the 5150 before it, the AT failed to make an appearance in Europe until ages after its US release. Even by the early spring of 1985, Guy Kewney in PCW was writing about how financial battles within IBM were preventing the company from selling to its European division at anything sufficiently below the retail price to make it worth selling. Not only that, but it was suggested that unreliable hard disks and chip shortages meant that quite often the machines didn't even work[source: "Fooling Yourself, Guy Kewney, Newsprint, PCW, March 1985 p.92].