Motorola, Intel, IBM Make a Mainframe in a PC – The PC XT/370
13 hours ago
- #IBM Mainframe
- #Vintage Computing
- #Hardware Hacking
- The IBM PC XT/370 was a unique system from the 1980s that transformed a standard IBM PC/XT into a mainframe-compatible desktop by adding three expansion cards.
- It utilized two Motorola 68000 microprocessors (one modified), an Intel 8087 Math Coprocessor (also modified), and 512KB of memory to emulate IBM System/370 mainframe functionality.
- The XT/370 could function as a standard PC/XT, an IBM 3270 terminal, and a machine capable of running some System/370 software.
- Despite its niche appeal, the XT/370 was surprisingly fast and cost-effective, priced at $8,085 compared to a basic PC/XT at $4,395.
- The modified 68000 executed a subset of System/370 instructions directly, with other instructions emulated by software, showcasing innovative use of microcode.
- Motorola and Intel collaborated closely with IBM, highlighting the shifting power dynamics towards semiconductor companies in the early 1980s.
- The XT/370 demonstrated the potential of microprocessors to encroach on mainframe territory and showcased the versatility of PC expansion slots.
- Though an evolutionary dead end for System/370 on desktops, the XT/370 remains a fascinating example of 1980s technological ingenuity.
- Today, enthusiasts like @TubeTimeUS are restoring XT/370 systems, preserving this piece of computing history.