5 ms·

Serially-attached SD for old PalmOS devices

89 points by dmitrygr 5y ago

TedDoesntTalk 5y ago
This is incredible reverse engineering work. Great job!
adrianmonk 5y ago
That is quite a project! Hardware, firmware, protocol reverse engineering, hacking Palm OS itself to support the hardware, and writing apps to make it useful. And to top it off, it's all done while working within the limitations of a mid-1990s device. Desktop computers were limited enough back then, but this is a portable device and is even more limited. To those who haven't worked in this environment (I used to write Palm apps), it may be hard to appreciate exactly how limited. For example, the article mentioned heap size. I forget the exact numbers, and it varied from one device to another, but the total heap for your entire program was something like 32 kilobytes on some devices.
- TedDoesntTalk 5y ago
  I wrote some Java apps for Palm. The limitations made it a fun challenge!
- zubiaur 5y ago
  Dmitry, the author, is nothing short of a genius. He was fixing many issues with palmos devices back in the day. If you ever used skinui, his sdhc drivers, or any of his palmpowerups it is evident that this guy understood palm PDAs at a fundamental level. I’m fan of his work.
dleslie 5y ago
I'm still a little bitter that Palm failed. I have my Z22 kicking around, still charged, and I noodle with it from time to time. I feel like Android and iOS sort of forgot about the professional and semi-professional market segments, which have been drowned out by broader demand and had their preferred featureset designed out in favour of an experience with a broader market appeal. Opening a Palm device feels like you're being invited to schedule something, take note of something, or otherwise make a productive choice. Opening my phone feels like I'm supposed to respond to WhatsApp and browse shitposts on Reddit.
- causality0 5y ago
  I spent years ticking back and forth between Palm and Pocket PC devices. Palm hardware quality was bad and Pocket PC software was terrible. To this day I wonder why Palm thought it was ok that all their LCDs emitted a high-pitched humming noise when turned on.
  - lxgr 5y ago
    > Palm hardware quality was bad They were definitely not perfect, but at the time (and at my budget as a middle school student), Palm devices were the only way to have a pocket-sized computer of my own that I could bring to and use in school. The shareware community was amazing, and it's almost impossible to imagine how much stuff I could fit into 2 MB of total system memory: An eBook reader and a couple of books, several games (shout out to Space Trader), a TV remote control, offline newspaper articles... Only to see it all disappear in a heartbeat when changing batteries, with no way to restore while traveling for the summer! (My m100 had a flaky capacitor and would sometimes do that.)
    - causality0 5y ago
      The design was fantastic. They just made bad choices about parts vendors, in my opinion.
  - Lammy 5y ago
    > To this day I wonder why Palm thought it was ok that all their LCDs emitted a high-pitched humming noise when turned on. Maybe it was designed by people who couldn't hear it? High-pitched sounds are supposedly the first to go with age/tinnitus/etc: https://mosquitoloiteringsolutions.com/why-mosquito/sound-deterrent-for-under-25s/ https://mosquitoloiteringsolutions.com/why-mosquito/sound-de...
    - markrages 5y ago
      That was the era of the elecroluminescent backlight. This technology required a high-voltage (~100V) squarewave across the mostly-capacitive EL panel. This squarewave was at audio frequencies. The panel also happened to function as a piezo tweeter, depending on mounting. I worked for a cell phone company at the time. I have two memories of this technology: 1. Using the prototype phone out of its case and touching the 100 V squarewave to my ear. That's some tender skin... 2. Using a primary transformer in reverse as an audio transformer, to play the lab stereo over EL panel. It turns out the panel color changes a little bit with frequency.
blamazon 5y ago
If you liked this, check out the author's projects page. Lots of cool stuff.
jamal-kumar 5y ago
I used to use a palm III for "redboxing" payphones back in the day in a country which didn't use multifrequency tones to signal a coin drop. Was pretty much the most fun I had with the thing, it had a BASIC interpreter you could download so writing little programs that could do stuff like that wasn't actually hard at all
orangepurple 5y ago
I miss the Palm OS and device aesthetic
- lxgr 5y ago
  Then go and run Palm OS on your smartphone (yes, also non-jailbroken iOS) right now :) https://cloudpilot-emu.github.io/ https://cloudpilot-emu.github.io/
billiam 5y ago
This old Palm guy loved the reverse engineering done here.
anonymousiam 5y ago
I had a TRG-PRO which was a classic Palm Pilot, but with a CF card slot in the back and built-in software to use the additional storage. I suppose it could have used a SD card if you adapted it with one of these: https://www.amazon.com/Compact-Memory-Adapter-High-Speed-Extreme/dp/B06XD8ZP1P https://www.amazon.com/Compact-Memory-Adapter-High-Speed-Ext... http://www.pencomputing.com/palm/Reviews/trgpro.html http://www.pencomputing.com/palm/Reviews/trgpro.html

89 points by dmitrygr 5y ago

This is incredible reverse engineering work. Great job!

That is quite a project! Hardware, firmware, protocol reverse engineering, hacking Palm OS itself to support the hardware, and writing apps to make it useful. And to top it off, it's all done while working within the limitations of a mid-1990s device. Desktop computers were limited enough back then, but this is a portable device and is even more limited. To those who haven't worked in this environment (I used to write Palm apps), it may be hard to appreciate exactly how limited. For example, the article mentioned heap size. I forget the exact numbers, and it varied from one device to another, but the total heap for your entire program was something like 32 kilobytes on some devices.

TedDoesntTalk 5y ago
I wrote some Java apps for Palm. The limitations made it a fun challenge!
zubiaur 5y ago
Dmitry, the author, is nothing short of a genius. He was fixing many issues with palmos devices back in the day. If you ever used skinui, his sdhc drivers, or any of his palmpowerups it is evident that this guy understood palm PDAs at a fundamental level. I’m fan of his work.

dleslie 5y ago

I'm still a little bitter that Palm failed. I have my Z22 kicking around, still charged, and I noodle with it from time to time. I feel like Android and iOS sort of forgot about the professional and semi-professional market segments, which have been drowned out by broader demand and had their preferred featureset designed out in favour of an experience with a broader market appeal. Opening a Palm device feels like you're being invited to schedule something, take note of something, or otherwise make a productive choice. Opening my phone feels like I'm supposed to respond to WhatsApp and browse shitposts on Reddit.

causality0 5y ago
I spent years ticking back and forth between Palm and Pocket PC devices. Palm hardware quality was bad and Pocket PC software was terrible. To this day I wonder why Palm thought it was ok that all their LCDs emitted a high-pitched humming noise when turned on.
- lxgr 5y ago
  > Palm hardware quality was bad They were definitely not perfect, but at the time (and at my budget as a middle school student), Palm devices were the only way to have a pocket-sized computer of my own that I could bring to and use in school. The shareware community was amazing, and it's almost impossible to imagine how much stuff I could fit into 2 MB of total system memory: An eBook reader and a couple of books, several games (shout out to Space Trader), a TV remote control, offline newspaper articles... Only to see it all disappear in a heartbeat when changing batteries, with no way to restore while traveling for the summer! (My m100 had a flaky capacitor and would sometimes do that.)
  - causality0 5y ago
    The design was fantastic. They just made bad choices about parts vendors, in my opinion.
- Lammy 5y ago
  > To this day I wonder why Palm thought it was ok that all their LCDs emitted a high-pitched humming noise when turned on. Maybe it was designed by people who couldn't hear it? High-pitched sounds are supposedly the first to go with age/tinnitus/etc: https://mosquitoloiteringsolutions.com/why-mosquito/sound-deterrent-for-under-25s/ https://mosquitoloiteringsolutions.com/why-mosquito/sound-de...
  - markrages 5y ago
    That was the era of the elecroluminescent backlight. This technology required a high-voltage (~100V) squarewave across the mostly-capacitive EL panel. This squarewave was at audio frequencies. The panel also happened to function as a piezo tweeter, depending on mounting. I worked for a cell phone company at the time. I have two memories of this technology: 1. Using the prototype phone out of its case and touching the 100 V squarewave to my ear. That's some tender skin... 2. Using a primary transformer in reverse as an audio transformer, to play the lab stereo over EL panel. It turns out the panel color changes a little bit with frequency.

blamazon 5y ago

If you liked this, check out the author's projects page. Lots of cool stuff.

jamal-kumar 5y ago

I used to use a palm III for "redboxing" payphones back in the day in a country which didn't use multifrequency tones to signal a coin drop. Was pretty much the most fun I had with the thing, it had a BASIC interpreter you could download so writing little programs that could do stuff like that wasn't actually hard at all

orangepurple 5y ago

I miss the Palm OS and device aesthetic

lxgr 5y ago
Then go and run Palm OS on your smartphone (yes, also non-jailbroken iOS) right now :) https://cloudpilot-emu.github.io/ https://cloudpilot-emu.github.io/

billiam 5y ago

This old Palm guy loved the reverse engineering done here.

anonymousiam 5y ago

I had a TRG-PRO which was a classic Palm Pilot, but with a CF card slot in the back and built-in software to use the additional storage. I suppose it could have used a SD card if you adapted it with one of these: https://www.amazon.com/Compact-Memory-Adapter-High-Speed-Extreme/dp/B06XD8ZP1P https://www.amazon.com/Compact-Memory-Adapter-High-Speed-Ext... http://www.pencomputing.com/palm/Reviews/trgpro.html http://www.pencomputing.com/palm/Reviews/trgpro.html