HP 97: Disable printer?

[Dave Britten]

I'm guessing the answer is no, but is there any way to disable the printer on the 97 and make all the print instructions act like on the 67? My printer is non-functional until I get a new paper advance roller, and it would be great if the print instructions just displayed values instead. Any hidden jumpers inside the machine that will change how it behaves?

[teenix]

(01-22-2021 06:12 PM)Dave Britten Wrote:  I'm guessing the answer is no, but is there any way to disable the printer on the 97 and make all the print instructions act like on the 67? My printer is non-functional until I get a new paper advance roller, and it would be great if the print instructions just displayed values instead. Any hidden jumpers inside the machine that will change how it behaves?

Your guess was correct as far as I know. The microcode would need changing to display print functions. As your are most likely aware, switching to MAN mode will stop printing unless a print function key is used.

cheers

Tony

[Dave Britten]

(01-22-2021 07:23 PM)teenix Wrote:  Your guess was correct as far as I know. The microcode would need changing to display print functions. As your are most likely aware, switching to MAN mode will stop printing unless a print function key is used.

cheers

Tony

Yeah, was wondering if anybody had disassembled the firmware and seen anything that appeared to be provisions for displaying instead of printing. I keep the calculator in MAN mode, but it would be nice to include PRX in programs for the long-pause effect from the 67, or actual printing later if I get the printer working.

[teenix]

(01-22-2021 07:42 PM)Dave Britten Wrote:  Yeah, was wondering if anybody had disassembled the firmware and seen anything that appeared to be provisions for displaying instead of printing. I keep the calculator in MAN mode, but it would be nice to include PRX in programs for the long-pause effect from the 67, or actual printing later if I get the printer working.

The 67 and 97 share some code but not in this regard.

It might have been nice to have this functionality but there would need to be another ROM added to store the extra code and a method to activate it.

cheers

Tony

[[kby]]

Not that it would be a desirable solution for this case (unless the ICs were available and the boards already socketed, do you think swapping the (appropriate, probabltb#0) ROMsbetween a -97 and a -67 would work?-kby

(01-22-2021 11:41 PM)teenix Wrote:  

(01-22-2021 07:42 PM)Dave Britten Wrote:  Yeah, was wondering if anybody had disassembled the firmware and seen anything that appeared to be provisions for displaying instead of printing. I keep the calculator in MAN mode, but it would be nice to include PRX in programs for the long-pause effect from the 67, or actual printing later if I get the printer working.

The 67 and 97 share some code but not in this regard.

It might have been nice to have this functionality but there would need to be another ROM added to store the extra code and a method to activate it.

cheers

Tony

[teenix]

(01-23-2021 12:22 AM)[kby] Wrote:  Not that it would be a desirable solution for this case (unless the ICs were available and the boards already socketed, do you think swapping the (appropriate, probabltb#0) ROMsbetween a -97 and a -67 would work?-kby

Not possible, as the code could not work.

It might be possible for my HP-97 replacement CPU board tho ;-)

cheers

Tony

[Dave Britten]

(01-23-2021 12:22 AM)[kby] Wrote:  Not that it would be a desirable solution for this case (unless the ICs were available and the boards already socketed, do you think swapping the (appropriate, probabltb#0) ROMsbetween a -97 and a -67 would work?-kby

(01-22-2021 11:41 PM)teenix Wrote:  The 67 and 97 share some code but not in this regard.

It might have been nice to have this functionality but there would need to be another ROM added to store the extra code and a method to activate it.

cheers

Tony

Given the vast difference between the keyboard layouts and requisite scanning logic, probably not. Would be an interesting experiment, though.

[Paul Berger (Canada)]

Another problem is the the 97 uses the PIK chip to scan the keyboard but the 67 does not. It can be done I used a 97 to test the chips from a non-working 67 that turned out to have a bad ACT chip. The differences in keyboard layout made it very difficult to do anything with it and I had to wire up some extra keys because the 67s layout has more rows that the 97.

[Chr Yoko]

(01-23-2021 01:07 AM)teenix Wrote:  It might be possible for my HP-97 replacement CPU board tho ;-)

cheers

Tony

What ? 8-)

[Paul Berger (Canada)]

(01-23-2021 01:07 AM)teenix Wrote:  

(01-23-2021 12:22 AM)[kby] Wrote:  Not that it would be a desirable solution for this case (unless the ICs were available and the boards already socketed, do you think swapping the (appropriate, probabltb#0) ROMsbetween a -97 and a -67 would work?-kby

Not possible, as the code could not work.

It might be possible for my HP-97 replacement CPU board tho ;-)

cheers

Tony

Speaking of that, where are you with your HP-97 replacement? I could use one for a 97 I have that does not have a functional PIK. I had tried a PIC from a 91 but that did not work so well as several of the code points for the printer are different, especially symbols printed for key codes when listing a program.

Paul.

[teenix]

(01-24-2021 02:46 AM)Paul Berger (Canada) Wrote:  Speaking of that, where are you with your HP-97 replacement? I could use one for a 97 I have that does not have a functional PIK. I had tried a PIC from a 91 but that did not work so well as several of the code points for the printer are different, especially symbols printed for key codes when listing a program.

Paul.

I thought I would have it completed by now, but being away for 7 months things ground to a halt. I am still at the prototype stage so quite a lot to do yet, but making progress.

Yes, the 91 PIK chip has a different character ROM to the 97.

cheers

Tiny

[teenix]

(01-23-2021 11:01 PM)Chr Yoko Wrote:  

(01-23-2021 01:07 AM)teenix Wrote:  It might be possible for my HP-97 replacement CPU board tho ;-)

cheers

Tony

What ? 8-)

Mostly documented here...

https://www.hpmuseum.org/forum/thread-12156.html

cheers

tony