<But there's a difference between a Z-80 running a text-mode interface, <and an 8088 running a GUI. Also, remember that Bill Gates didn't know Not much. Some z80 systems were faster, considering by time thge 4.77 mhz 8088 was making inroads around 84ish the z80s were cranking at 8mhz some faster. Also the 8088 was anout the same efficientcy as the z80 for byte data. There were a few z80 system with 128k or more of ram running at 6mhz around the time of the PC introduction. I have a Visual1050 (early 1984) that is z80 128kb ram and GUI capable running CPM and GSX-80 all competing with PC GUI systems. Nice box with 10mb hard disk and two 400k floppies and mono monitor. <very much about operating systems, as opposed to languages. MS Windows <is the only OS MS programmed ground up, something they only started No. The internal file system (disk operating system <dos>) used on the TRS80 disk basic was amoung the many that preceeded it that was before 1979. The file system was FAT based. <after the A1000. And, I've never seen Windows multitask under 8MB in the <way the Amiga or a UNIXoid computer can. W3x was not preemtive nor very good coopertive multitask. And even with 32mb didn't change that. It would take w95 to get to that point. CPM in the guise of MPM was doing for years by then. I'd also had CP/M multitasking in 64k in '81. No majik. There was also multiuser basic for Altair and NS* had a multiuser version of the NS* OS. <>> and Gates replied that multitasking really wasn't possible in <>> anything under 8 megs of ram. To which the same reporter replied, The PDP-11s running RSTS (or TSX-11) in the 70s didn't multitask either... sometimes with several dozen users usually in 64kb and maybe 256kb of ram. But heck the PDP-8 was doing in before that in 8kw (RTS-8 or os/8). Of course if you want something modern that can multitask in less than 8mb VAX/VMS (runs fair in 4mb!). Allison