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Matt Agajanian · 06-01-2022, 08:03 PM

Hi all.

Was it possible to record a program with up to 112 steps on one side and data on the other side?

teenix · (This post was last modified: 06-01-2022 09:02 PM by teenix.)

No reason why not. The card sides aren't linked in any way. The HP microcode knows what is stored on the card from the card status information.

cheers

Tony

Dave Britten · 06-01-2022, 10:53 PM

Yup. Just have a program that's no more than 112 steps on one side, and data from only the primary registers on the other.

I think I've read some tips/articles in PPC Journal that mentioned having more steps/data in memory when writing the card so that you still get one side of the card prompting you with "CRD" to pass the other side through.

Matt Agajanian · 06-02-2022, 01:41 AM

Cool! Thanks.

teenix · 06-02-2022, 02:39 AM

(06-01-2022 10:53 PM)Dave Britten Wrote: Yup. Just have a program that's no more than 112 steps on one side, and data from only the primary registers on the other.

I think I've read some tips/articles in PPC Journal that mentioned having more steps/data in memory when writing the card so that you still get one side of the card prompting you with "CRD" to pass the other side through.

Also, programs with more than 112 steps or maximum RAM storage doesn't have to go on the same card, but it is more sensible. It also doesn't matter which side of the card you put in first when reading, the microcode figures it out from the Status information on the card side.

cheers

Tony

tangdfx · 06-02-2022, 02:25 PM

Hi，Tony

Is it possible that the program and data save on the same card side.

If it is not possible on the original hp67，is it possible on your HP67C ？

Thank you.

Dave Britten · 06-02-2022, 05:08 PM

(06-02-2022 02:25 PM)tangdfx Wrote: Hi，Tony

Is it possible that the program and data save on the same card side.

If it is not possible on the original hp67，is it possible on your HP67C ？

Thank you.

Not on the original 67/97. One card side holds either program steps or register data.

The TI-59 has a slightly dumber/more flexible approach to memory and cards. The calculator has 960 bytes of RAM divided up between program steps and storage registers (by default, 480 program steps and 60 registers, or a 50/50 split). You can allocate between 0 and 100 storage registers in increments of 10 (80 bytes), with the rest being treated as program memory.

Each side of a card holds 240 bytes (30 registers), or 25% of the calculator's memory. Thus there are four notional "banks" in memory, and two cards written on both sides can hold the complete memory of the calculator. Any one of those four banks can be written to the side of a card, by entering 1-4 into the display, pressing 2nd Write, and feeding in a card. That card side will be tagged with the bank number, and will be automatically read back into the correct bank (unless manually overridden).

If you've configured the calculator with a number of registers other than a multiple of 30, then you can potentially write a bank containing a combination of program steps and registers onto one card side. As far as the TI-59 is concerned, it's just reading raw bytes from the card into memory - how they are subsequently interpreted depends on how the memory has been partitioned.

The 59 card reader being "dumb" does offer one trick that I use often: after you write a program card, you can manually read it back into bank 4 (top of memory, where storage registers 0-29 live) by entering -4 into the display and feeding in the card. This will verify the card can be read without erasing the program steps in the lower banks of memory.

teenix · (This post was last modified: 06-03-2022 12:18 AM by teenix.)

(06-02-2022 02:25 PM)tangdfx Wrote: Hi，Tony

Is it possible that the program and data save on the same card side.

If it is not possible on the original hp67，is it possible on your HP67C ？

Thank you.

As Dave mentioned not on the original 67.

The 67 and (C) CPU boards imitate the way the CRC chip works so that the original HP-67 microcode can work normally to read/write the cards and therefore operates the same as the original 67. This approach by HP allows different operations with the cards such as Merge.

It is possible to put any data on the cards with the CPU board but would still be limited to the 952 bits. However the chip used for the 67 CPU board does not have much spare program storage remaining and a modification such as this will require more than is available.

cheers

Tony