Mod. 5140 - IBM's First Laptop Computer • Hacker News Board

Re: Mod. 5140 - IBM's First Laptop Computer

#41

Post by iancmceachern » Sun, Oct 05, 2025, 7:11 PM UTC

criddell wrote: post #25

iancmceachern wrote: post #13

Earlier quoted context omitted.

I'm down. I can design and build it, if there are folks out there who are keen to do the other aspects of a business please feel free to reach out.

Maybe you can answer this then. Back in the early 80’s, Radio Shack made the TRS-80 Model 100 laptop. It ran for 20+ hours on 4 AA batteries. A few years later, Psion came out with a series of small devices that ran on 2 AA batteries and got 30+ hours of runtime. With modern electronics and displays, could something like a model 100 be made that could run for hundreds or even thousands of hours on 4 AA batteries?

As others have noted, its the "modern display" that does it.

From the wiki here:

"Display: 8 lines, 40 characters LCD, twisted nematic (gray) monochrome, with 240 by 64 pixel addressable graphics. The screen is reflective, not backlit.[3] The screen was made by Sharp Electronics.[4] The LCD controllers are by Hitachi: (10) HD44102CH column controller ICs and (2) HD44103CH row driver ICs; the HD44102CH's provide the programmable hardware interface to software. The refresh rate is about 70 Hz (coarsely regulated by an RC oscillator, not a crystal)."

It's not even backlit.

Re: Mod. 5140 - IBM's First Laptop Computer

#42

Post by criddell » Sun, Oct 05, 2025, 7:53 PM UTC

iancmceachern wrote: post #41

criddell wrote: post #25

Earlier quoted context omitted.

Maybe you can answer this then. Back in the early 80’s, Radio Shack made the TRS-80 Model 100 laptop. It ran for 20+ hours on 4 AA batteries. A few years later, Psion came out with a series of small devices that ran on 2 AA batteries and got 30+ hours of runtime. With modern electronics and displays, could something like a model 100 be made that could run for hundreds or even thousands of hours on 4 AA batteries?

As others have noted, its the "modern display" that does it. From the wiki here: "Display: 8 lines, 40 characters LCD, twisted nematic (gray) monochrome, with 240 by 64 pixel addressable graphics. The screen is reflective, not backlit.[3] The screen was made by Sharp Electronics.[4] The LCD controllers are by Hitachi: (10) HD44102CH column controller ICs and (2) HD44103CH row driver ICs; the HD44102CH's provide the p…

Surely a display of similar specs made today would draw a fraction of the power the similar panel from 1983 did, no?

Re: Mod. 5140 - IBM's First Laptop Computer

#43

Post by SilentM68 » Sun, Oct 05, 2025, 11:45 PM UTC

It's interesting but I remember seeing Radio Shack TRS80 Model 100 Laptop at the RadioShack store and wanting it, but mom said no. I had to settle for the Color Computer, since it was somewhat cheaper. People usually remember IBM PC but don't realize that there were many other brands out there. In my high school days, we had access to Apple I & IIs as well as TRS80 Model III machines. TRS80 machines came with DOS, BASIC & Editor Assembler, which were taught at our high school digital class.

TRS80 100 https://www.oldcomputers.net/trs100.html

TRS80 Model III https://www.oldcomputers.net/trs80iii.html

COCO https://www.oldcomputers.net/coco.html

Re: Mod. 5140 - IBM's First Laptop Computer

#44

Post by michaelsmanley » Mon, Oct 06, 2025, 2:41 PM UTC

reaperducer wrote: post #32

lemonlearnings wrote: post #11

Earlier quoted context omitted.

Any details to share re. specs, operating system?

I had one. Great little system. Built like a tank, and just as heavy. Incredibly forward-thinking modular architecture. Keyboard, memory, drives, serial port, parallel port, even the screen could be replaced just by the turn of a lever or a push of a button. Fantastic keyboard, even by today's laptops standards. Ate batteries like M&Ms. I almost always kept it plugged in. At the time, running it off the pair of 720k…

Yeah, when I say "nice" about the screen, it is all relative. Mine was nice compared to the original screen on the Model 1.

There are very few pieces of laptop/notebook hardware that I really enjoyed. The 5140 was one of them. I doubt I'd enjoy it now, but 40 years ago I found it just lovely.

Re: Mod. 5140 - IBM's First Laptop Computer

#45

Post by iancmceachern » Mon, Oct 06, 2025, 5:05 PM UTC

criddell wrote: post #42

iancmceachern wrote: post #41

Earlier quoted context omitted.

As others have noted, its the "modern display" that does it. From the wiki here: "Display: 8 lines, 40 characters LCD, twisted nematic (gray) monochrome, with 240 by 64 pixel addressable graphics. The screen is reflective, not backlit.[3] The screen was made by Sharp Electronics.[4] The LCD controllers are by Hitachi: (10) HD44102CH column controller ICs and (2) HD44103CH row driver ICs; the HD44102CH's provide the p…

Surely a display of similar specs made today would draw a fraction of the power the similar panel from 1983 did, no?

Not really. Fundamentally things like this are driven by physics, not engineering or cleverness.

We've had solar powered calculators with LCD displays for decades. We're not really going to get much lower power without changing Fundamental technologies at the material and physics level. Much of what we have material and physics wise "is what it is", on this planet anyway.