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HP-71b DTH$() and HTD() commands - Printable Version

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HP-71b DTH$() and HTD() commands - Don Shepherd - 07-23-2010

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 - Raymund Heuvel - 07-23-2010

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 - John Pierce - 07-23-2010

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 - Don Shepherd - 07-23-2010

Thanks Raymund and John. I wasn't aware of the address space on the 71b, and now these commands make some sense.