padama@batcomputer.tn.cornell.edu (padama) (03/03/88)
I'm posting the following for a friend who does not have access to the net: Does anyone know of an algorithm for converting IEEE format floating point numbers to bcd floating point? Is there a commercially available program in 'C' or 68881 assembler to do this? Please respond to the net or to my mail id You could also email to kri@cornella.ccs.cornell.edu. Thanks, Padma Krishnaswamy
geof@imagen.UUCP (Geoffrey Cooper) (03/04/88)
In article <3910@batcomputer.tn.cornell.edu>, padama@batcomputer.tn.cornell.edu (padama) writes: > Does anyone know of an algorithm for converting IEEE format floating point > numbers to bcd floating point? You're in luck. BCD and IEEE are two formats supported by the 68881 hardware. The machine co-instructions of the 68881-68020 combination include commands to fetch a number from either format into a register and write it back in either format. So you can accomplish what you want in two 68881 FMOVE.x instructions. See the manual for details. - Geof -- {decwrl,sun,saber}!imagen!geof
stever@videovax.Tek.COM (Steven E. Rice, P.E.) (03/05/88)
In article <3910@batcomputer.tn.cornell.edu>, Padma Krishnaswamy (padama@batcomputer.tn.cornell.edu) writes: > I'm posting the following for a friend who does not have access to the net: > > Does anyone know of an algorithm for converting IEEE format floating point > numbers to bcd floating point? Is there a commercially available program > in 'C' or 68881 assembler to do this? Please respond to the net or to my > mail id. The 68881 fmove instruction will do this. Storing a value as a BCD result will convert it to a packed decimal string (2 digits per byte) with an exponent, as appropriate. The 68020 has an unpack instruction which allows unpacking the result as one digit per byte, with an appropriate value (hex '3' is useful) in the upper 4 bits of each byte. Steve Rice ----------------------------------------------------------------------------- * Every knee shall bow, and every tongue confess that Jesus Christ is Lord! * new: stever@videovax.tv.Tek.com old: {decvax | hplabs | ihnp4 | uw-beaver}!tektronix!videovax!stever