the3dfxdude
Experienced Member
Has anyone worked with early IBM touchscreen calibration? Is it a fairly hard thing to get right?
I have an IBM 4055, and I am not sure how unique the design is. I think it is similar to other IBM touchscreen design, particularly the one was sold as an external overlay to a monitor in later years. This one is built in and sold this way. Basically it is a glass that sits over the actual CRT. There is some kind of wire wrapping around the edges where you can't see. The idea I think is to deflect the touchscreen glass or measure pressure where you are tapping. I got this information from a diagram from the service manual.
The IBM guide to operations disk for the 4055 has a calibration routine. The system has a battery that keeps the calibration settings onboard inside the monitor. But unfortunately the lithium battery died about 2 years ago. I installed a new battery and the monitor is working, and I can access all the functions in the IBM guide to operations software. It will detect touches to the screen, but I must run the calibration. Otherwise the control program will not load, and none of the menu buttons in the IBM software will respond correctly to touching the right spot. No part of the screen seems to recognize any button. But it will respond to things like "touch anywhere" and the calibration.
So in calibration, it requires you to touch like 18 asterixes with the end of a pencil eraser. You are suppose to line up the eraser so that it is covering up the asterix when looking straight on. After pressing the 18 asterixes, then it does some calculations. If it thinks some of points were not pressed right, it asks you to press them again. It only lets you three attempts, and then it makes you start completely over. I've almost pressed all once before, maybe down to just one, but no success yet.
There is a C/Basic library that you can use to write your own program on the control program disk. But after trying that route, the functions will return error saying unable to send or receive data at all. The instructions say to run two things before running your own program. One is the initial setup program, which will bring you to a menu where you can calibrate. You can also use a switch to skip the menu I think. But anyway, I cannot finish calibration, so I always have skipped it. Then after exiting that program it says "System loaded". The next program when I run, it says, "Control program not loaded". If you proceed and run your own program, like I said, the example program or your program cannot communicate with the display.
I know a couple things. 1) the IBM software can communicate with the display and detect touches. 2) but you might not be able to with third-party software unless the touchscreen portion of the display is fully calibrated. I'm left with thinking I either need to disassemble the IBM software and find out how it works, or inspect the logic boards inside the display, particularly the part where it inputs from the touch screen and transmits to the PC. I haven't removed the touchscreen piece, and I'd rather not. It's a clean display, no damage I can see, and seems to be working. I have seen some of the boards still installed and they also appeared fine.
So I am hoping someone might know a bit of the calibration process, if there are similar displays out there, if this rings a bell.
I have an IBM 4055, and I am not sure how unique the design is. I think it is similar to other IBM touchscreen design, particularly the one was sold as an external overlay to a monitor in later years. This one is built in and sold this way. Basically it is a glass that sits over the actual CRT. There is some kind of wire wrapping around the edges where you can't see. The idea I think is to deflect the touchscreen glass or measure pressure where you are tapping. I got this information from a diagram from the service manual.
The IBM guide to operations disk for the 4055 has a calibration routine. The system has a battery that keeps the calibration settings onboard inside the monitor. But unfortunately the lithium battery died about 2 years ago. I installed a new battery and the monitor is working, and I can access all the functions in the IBM guide to operations software. It will detect touches to the screen, but I must run the calibration. Otherwise the control program will not load, and none of the menu buttons in the IBM software will respond correctly to touching the right spot. No part of the screen seems to recognize any button. But it will respond to things like "touch anywhere" and the calibration.
So in calibration, it requires you to touch like 18 asterixes with the end of a pencil eraser. You are suppose to line up the eraser so that it is covering up the asterix when looking straight on. After pressing the 18 asterixes, then it does some calculations. If it thinks some of points were not pressed right, it asks you to press them again. It only lets you three attempts, and then it makes you start completely over. I've almost pressed all once before, maybe down to just one, but no success yet.
There is a C/Basic library that you can use to write your own program on the control program disk. But after trying that route, the functions will return error saying unable to send or receive data at all. The instructions say to run two things before running your own program. One is the initial setup program, which will bring you to a menu where you can calibrate. You can also use a switch to skip the menu I think. But anyway, I cannot finish calibration, so I always have skipped it. Then after exiting that program it says "System loaded". The next program when I run, it says, "Control program not loaded". If you proceed and run your own program, like I said, the example program or your program cannot communicate with the display.
I know a couple things. 1) the IBM software can communicate with the display and detect touches. 2) but you might not be able to with third-party software unless the touchscreen portion of the display is fully calibrated. I'm left with thinking I either need to disassemble the IBM software and find out how it works, or inspect the logic boards inside the display, particularly the part where it inputs from the touch screen and transmits to the PC. I haven't removed the touchscreen piece, and I'd rather not. It's a clean display, no damage I can see, and seems to be working. I have seen some of the boards still installed and they also appeared fine.
So I am hoping someone might know a bit of the calibration process, if there are similar displays out there, if this rings a bell.