HP67 running

[teenix]

Hi Bernhard,

Thanks for the link. I was aware of some of the people that laid a lot of the ground work for opening up these calculators and I certainly do find their efforts impressive. Because of limited resources I have had to rely on some of those efforts at times for my own emulator and am grateful for their hard work, although I have tried as much as possible to be my own detective otherwise the journey of discovery is quite bland.

The read/write was simpler to create than I thought it was going to be as the calculator code does all the hard work, although as usual there was a quirk. All you need to do is make the program data available or be ready to receive it when required.

Basically...

each cardArray element = array [0..13] of Integer

[Write - to card]
CRC 260 - motor on
index = 0

CRC 1700
if write
cardArray[index] = crc_Reg_$90
inc index

CRC 360 - motor off
if write...
save cardArray to disk


[Read - from card]
Load program file into cardArray
index = 7 // why this is so escapes me ???

CRC 1700
if read
Place cardArray[index] into crc_Reg_$99
inc index

CRC 360 - motor off
if read...
nothing to do

Data files, merge etc work exactly the same

The only thing I can't explain is that on a [read] the first 7 data elements which are supposed to be zero's cause a problem with the calculator firmware and the read fails. If I set the array index to 7, bypassing these bytes, it all works.


I got a bit carried away as I found a sound recording of a real card reader and activates on CRC 260 (motor on) - although there is a menu item to leave it off.

cheers

Tony