Didn't Gates say 640K (which was the amount of space left in the 8086/8088 one megabyte address space after you removed the space for the ROM, graphics and other memory mapped devices).
Maybe I’m mistaken but I thought it was 64.
I believe you are correct.
My IBM PC-1 (still have it) came with 16kB of DRAM and cassette basic and had chip sockets so you could increase it to 64kB I believe. Then with the addition of other cards and a multipurpose card (I forgot the name of it) you could fill it out to the maximum of 640kB. That multipurpose card also provided a battery backed up real time clock so you didn’t have to type in the time and date every time you booted the machine...
It had dual monitors, a monochrome and CGA/color monitor.
It had dual 5-1/4” 360k double sided floppy drives.
A little later I got a 20 MB hard drive and 8087 coprocessor for it. I wrote an assembly language floating point math library using the 8087 coprocessor that increased the math computational speed by a factor of 7 doing linear circuit analysis... It was really cool...
It was allegedly 640K. But, it's the equivalent of an urban legend. Gates was never actually quoted saying that.