HP Forum Archive 19

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HP-71b DTH$() and HTD() commands Message #1 Posted by Don Shepherd on 23 July 2010, 2:49 p.m. I am curious about the background of these commands to convert between decimal and 5-digit hex values. What's so special about 5-digit hex values? Does it have anything to do with importing machine code into the 71b?

Re: HP-71b DTH$() and HTD() commands Message #2 Posted by Raymund Heuvel on 23 July 2010, 5:19 p.m., in response to message #1 by Don Shepherd Hi Don Assumption: 71B addresses are 20 bit -> 5 nybbles. The 71B Peek and Poke commands use 5 nybble addresses. Also Forth is 20 bit based, probably also due to the 20 bit 'A' field in the working registers. BR Ray

Re: HP-71b DTH$() and HTD() commands Message #3 Posted by John Pierce on 23 July 2010, 5:24 p.m., in response to message #1 by Don Shepherd There are five HEX digits in the highest memory address in the HP-71B, .... FFFFF(HEX)=1048575(10).

Re: HP-71b DTH$() and HTD() commands Message #4 Posted by Don Shepherd on 23 July 2010, 6:23 p.m., in response to message #1 by Don Shepherd Thanks Raymund and John. I wasn't aware of the address space on the 71b, and now these commands make some sense.

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