5 ms·
It is amusing to note that on mini computers of the 1970's that what we now would call a "floating point co-processor" was a hardware option. Even with the Int
by DannyB2 7y ago
It is amusing to note that on mini computers of the 1970's that what we now would call a "floating point co-processor" was a hardware option. Even with the Intel 8086, a "math" coprocessor was a separate 8087 chip.
On mini computers you used a different version of the language compiler depending on whether your hardware had this coprocessor or not. Typically you didn't make this choice, but the system administration people made sure the correct compilers were installed to generate hardware supported floating point or software floating point. That tradition seemed to make its way into PCs. It was a while before you could just assume that everyone had hardware supported floating point. Oh, and every language's software floating point was annoyingly different. So no portable way of writing binary floating point -- you had to convert to/from ASCII.
GPUs are like a new fangled hardware floating point external to the CPU. Now to gradually become part of the main system again.
- reaperducer 7y agoEven with the Intel 8086, a "math" coprocessor was a separate 8087 chip. Even later than that. The 80386 had the 80387 in 1987, and the 68030 had the 68881 in 1984. The '881 was the first square chip I ever used.
- twoodfin 7y agoThe Intel ‘486 had the FP coprocessor integrated, but they split the line into the DX and SX models. The only difference was that the SX had the FP unit physically disabled.
- kijiki 7y agoThey still sold a 80487, of course. It was a '486 without the FPU being fused off, and when you plugged it into the "math co-processor" socket, it disabled the original CPU and took over both duties.
- DrScump 7y agoMy first computer was an IBM AT-compatible Zenith with an 80286. I bought an Intel AboveBoard memory board to fill out conventional memory to 640K and add extended memory. At the time, there was a promotional mail-in coupon for a free 80287 coprocessor direct from Intel, so I added that for free!
- univacky 7y agoCompilers like MS and Turbo C used a clever technique - a program could be compiled with a software floating point library and shipped, and the existence of the FP coprocessor would be detected at runtime and the program would self-modify appropriately. If there was a coprocessor, the first time any particular FP routine was called, it would overwrite the instruction calling the library with the appropriate FP coprocessor instruction.