Compaq Deskpro 8086 (1984) - The original 100% IBM-compatible PC Clone Now here is an interesting unit recently discovered... an original Compaq Deskpro 8086 from 1984! This was *the* very first system, along with the original Compaq Portable, to be 100% IBM-compatible. Of course other systems had x86 processors such as the 8088 and 8086 back in the 1980s, along with an 8-bit ISA bus, but many of them were only up to 95% code-compatible. This meant that the code either had to be patched to run on the non-compatible system, or a specific vendor-version of the software needed to be released. This was not the case with the Compaq Deskpro, though! This unit is running with the following hardware specifications: - AMD 8086-2 16-bit CPU @ 4.77MHz (the original CPU of which the x86 instruction set architecture was based on, from 1978 - second-sourced AMD model rated for 8MHz) - Intel 8087 16-bit FPU @ 4.77MHz ~ 50 KFLOPS computational processing capability - 640KB of DRAM (20-bit address bus - lower 640KB used for system memory - upper 384KB reserved for hardware) - ISA Compaq CGA Video Processor w/ 16KB VRAM - ISA 3COM 3C503 10BASE-T/10BASE-5 NIC from 1989 (the very first 3COM NIC to feature a built-in Ethernet transceiver) - ISA XTIDE Compact Flash card w/ 2GB CF Card - ISA FDD Controller w/ twin 1.2MB 5.25" FDDs - ISA ST-412 HDD Controller w/ twin Seagate ST-225 20MB MFM HDDs - ISA Serial/Parallel Clock I/O Card - MAGNAVOX Computer Monitor 80 composite amber monochromatic monitor from 1989 - 65 watt AT-compatible PSU UPDATE: - AMD 8086-2 16-bit CPU was removed - NEC V30 16-bit CPU @ 4.77MHz - 8086-compatible CPU with 8080 ISA compatibility and an 18% performance boost clock-for-clock compared to the the 8086 With the NEC V30, the disk transfer speeds are now around 160KB/s, and FTP transfers are up from 35KB/s to 38KB/s; a modest improvement for a simple drop-in CPU upgrade. --------------------------------------------- Well now, I'm surprised to see everything this system from 1984 is capable of running! The system is currently running either MS-DOS 6.22 as the main OS, FreeDOS 8088/8086 for newer software compatibility, and MINIX 2.0.2 for UNIX kernel and application testing and compiling. I have setup this system with some of the mTCP networking software (special thanks to Michael Brutman) and have this system acting as a full-fledged FTP server. With the 8086 CPU @ 4.77MHz and 3COM 10BASE-T NIC, it is capable of 35KB/s upload and 25KB/s download. It may be possible to improve the speed by upgrading the CPU to an NEC V30 or V33, which are essentially 3rd party x86 CPUs capable of the Intel 8080 ISA or 80286 performance-per-clock, respectively. Both have a nice processing capability boost, which should result in higher transfer speeds; an 80286 or 80386 CPU accelerator board is also possible, which would improve the CPU processing capability by 30% to 100%. While this unit does not have a soundcard, it is still capable of playing games on this luxurious amber monochromatic composite MAGNAVOX Monitor 80 from 1989. Even Freddy Krueger enjoys playing a game or two! The benchmark program is CheckIt, and is freely available for download online. Disk speed with the 20MB MFM HDDs is around 50KB/s, but the 2GB Compact Flash card caps out around 150KB/s; a worthy improvement for such a venerable system. The Intel 8087 FPU @ 4.77MHz has around 50 KFLOPS of computing capability. While this may not sound like much by today's standards, considering a NVIDIA GTX1080 has SP FP32 computational processing capabilities of over 10 TFLOPS, back in the 1980s, a FPU in such a small system was invaluable for scientists, developers, and statistics computation. Microsoft QuickBASIC 4.5 can take full advantage of the FPU when designing 3D graphics and animation. Computation takes around 30 seconds with only the CPU and software libraries, whereas with the FPU included, computation takes only around 9 seconds. --------------------------------------------- Now, the 8086 is a very interesting CPU, and unlike its 8088 brother CPU, this one has the full 16-bit data-bus! Both are 16-bit CPUs, but the 8088 only had an 8-bit data bus, resulting in half the performance at the cost of compatibility with 8-bit ICs back in the day. This is the same reason the 80386DX was such an advantage over the 80386SX as well, as the SX only had a 16-bit data bus, compared to the DX's full 32-bit data bus. The 88 and SX models were kind of the "Celeron" processors of their time, being low-cost but still keeping the compatibility of the full processors. Similarly, the Pentium Overdrive was also a real Pentium, but the data bus on it was only 32-bit, compared to the 64-bit data bus of the native Pentium. This was done in order to fit the 32-bit data bus of the 80486, but because of this, it took two clock cycles to do what the native Pentium could do in one clock cycle due to half the data bus. --------------------------------------------- I do have a few upgrades possibly planned for this system, however. Included in those upgrades will be the NEC V30 CPU, which is now done, and if I can find it, the extremely rare and elusive NEC V33 CPU. The NEC V30 was an 8086-compatible CPU with 8080 ISA compatibility, but the V33 was an 8086-compatible CPU with 80286 performance-per-clock, had 80186 ISA compatibility, and was about three times faster clock-for-clock over the stock 8086. The NEC V20, on the other hand, was an 8088-compatible CPU which gave an automatic 10% performance boost over the 8088 clock-for-clock, and had 8080 ISA compatibility as well built in; it was a nice drop-in upgrade for systems back then. There was also an NEC V33A which was an 80286 ISA compatible processor with protected memory mode as an alternative, and those can be found pretty easily on Yahoo Japan Auctions (or a proxy like buyee.jp), but these are only for systems with an 80286 present. --------------------------------------------- Stay retro!