General Caption: Emphemerides, Calculations, Al Khwarizmi (c.780--c.850):
The ephemeris is written in Medieval Latin and uses Roman numerals. The zodiac constellations or zodiac signs listed in the lower right box.
The image itself is from Otto E. Neugebauer's (1899--1990) The Astronomical Tables of al-Khwarizmi, (1962).
Al Khwarizmi (c.780--c.850) was a Persian Medieval Islamic mathematician, Medieval Islamic astronomer, and Medieval Islamic geographer.
Among other things, he wrote the book Al Jabr (c.820) from whose title we derive the word algebra.
Al Khwarizmi's own name mutated into the modern word algorithm. He is the eponym of algorithm.
Algorism ultimately defeated abacism. You can do a very fast simple calculation with an abacus, but there is NO record of the calculation, and so to check the calculation you have to do all the steps over again and probably make a new mistake. And, of course, there is way to go beyond simple calculations. So algorism, with its written record and ability to on to more and more elaborate calculations, had to win.
To give a comparison case: the abacus was like a calculator; algorism was like a computer.