----- Original Message ----- ----- Reply: ----- I suppose within the paradigm of the day you could consider the 603 and 604 "numeric co-processors", the only electronic (tubes of course) components in an otherwise electro-mechanical "system". The 603's claim to fame is that it's considered to be "the first mass-produced commercial electronic calculating device" and the 604 which came two years later in 1948 was an improved version which, as Chuck points out, added division capabilities. Having myself worked with the 604 (640 kilos/4 m3) I had to chuckle at its being called 'a miniature electronic calculator'; the word 'miniature' certainly had a different meaning in the context of the day: http://www.science.uva.nl/faculteit/museum/604.php Wish I'd kept my IBM manuals, including the 604; the person to whom I sent them years ago (you know who you are ;-) solemnly promised to make them available on the 'web, but I haven't found them so far... BTW, FWIW with a little fancy programming the 40x series of 'tabulating machines' could also be made to multiply, albeit *very* slowly... ;-) mike