News: 0175782279

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How a Retrocomputing Enthusiast Got a 30-Year-Old Clamshell Computer Online (youtube.com)

(Sunday December 29, 2024 @03:34AM (EditorDavid) from the Palmtop-PC dept.)


It had a 4.8-inch display. Introduced in 1991, Hewlett-Packard's (DOS-based) HP 95LX Palmtop PC — a collaboration with Lotus — was finally discontinued back in 2003.

But one found its way to long-time Slashdot reader [1]Shayde (who in November [2]repaired a 48-year-old handheld videogame console from Mattel ). "I really wanted to get this HP95LX talking to the internet at large," they told Slashdot, " but network stacks for DOS in 1991 were pretty limited, and this machine didn't even have the hardware for a network connection.

"It did have a serial port though — a flat 4-pin custom interface. I did a bunch of research and learned how to custom-build an RS-232 hookup for this port, and using an external Wifi module, got it online — and talking to the retrocomputing BBS!"

There's [3]a video documenting the whole experience . (Along the way he uses 20-gauge hook-up wire from Amazon, a zip tie, solder cups, and an internet modem (the WiFi232 [4]Hayes modem emulator ). The whole thing is powered by two AA batteries — it has 512K of memory, and about half a meg of storage. My favorite technical detail?

"Conveniently, the HP 95 [Palmtop PC] uses the exact same pinout as the [5]HP 48GX handheld graphing calculator . So looking up on the Internet, we can determine what pins we need to map from the HP unit over to what would be a DB25 serial port..."



[1] https://www.slashdot.org/~Shayde

[2] https://games.slashdot.org/story/24/11/09/2049218/retrocomputing-enthusiast-repairs-mattels-48-year-old-handheld-videogame

[3] https://www.youtube.com/watch?v=7Ub94fbx7fM

[4] https://biosrhythm.com/?page_id=1453

[5] https://en.wikipedia.org/wiki/HP_48_series#/media/File:HP48GX_Calculator.jpg



Serial Cable (Score:2)

by JBMcB ( 73720 )

Those HP palmtops were amazing when they came out. There were other palmtops that ran various mutant versions of DOS, but the 95 ran full-blown DOS 3.22.

It's a neat project, but I don't quite understand all the reverse engineering going on with the serial port. You can buy a 90's standard 4-pin HP serial cable on eBay for $20. I still have one for my 48GX knocking around somewhere.

80s and early 90s (Score:2)

by backslashdot ( 95548 )

Every year there was a visible bump in technology. There were many things to be wow'd by in that era.

Pretty sure the mid 80s to mid 90s was by far the greatest decade for computing, if not other things. Man if only I went back to that era with the knowledge of today. Fuck.

Re: (Score:2, Funny)

by 93 Escort Wagon ( 326346 )

Hey, if you ever do make it back... at some point try to get word to the Ukrainians that they shouldn't give up their nukes.

What's special here? (Score:2)

by TurboStar ( 712836 )

YouTube is filled with hundreds of people restoring and improving old machines. Systems from the 1970s and 80s all have internet connectivity now. The RS232 to WiFi thingamabobs have been around as long as the ESP8266, perhaps even before that. It's cool that he got it running and made a video. Just not sure why it's here as news.

Someone got a Bendix G-15 running this month, which is certainly more newsworthy as it's from 1956. [1]https://youtu.be/-HibkocVn1U [youtu.be]

[1] https://youtu.be/-HibkocVn1U

Re: (Score:2)

by OrangeTide ( 124937 )

Yea. I did things the hard way and used my RS-232 cable to connected my 200LX to a Linux box. I spent an afternoon chatting with my friends on IRC before I got fed up with the keyboard. I didn't get very far with getting SLIP and TCP/IP working, but it is all theoretically possible.

The big advantage between the 95LX and 200LX is the higher resolution (640x200) that makes 80x25 and 40x25 text quite readable. The 95LX's 240x128 panel made for some weird wrestling with some DOS apps. I have both but rarely use

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