Handspring Visor Memory Upgrade

In August of 2001, I got real gutsy. How, you ask? Well, I decided to take a geek-like plunge, and disassemble my Visor.

For the uninitiated, the “Visor” is a Palm Pilot clone, of sorts. The story goes like this: the three gurus responsible for the PalmOS and Palm Pilot, created their own company (Handspring) and set out to make a better Palm. I believe they did just that. You can read more about it at Handspring.

My first Visor (their flagship PalmOS product) was the Solo, which had 2MB of DRAM. Very small, in today’s large memory PDA machines. Still, for its time, it was great. I managed to keep from hitting the memory ceiling by keeping a streamlined tight ship, so to speak. I only installed the most necessary apps onto my Visor, and kept just a few games.

HandSpring Visor Solo
HandSpring Visor Solo

Nevertheless, it wasn’t long before I crept up to the 2MB limit of my handheld. And then last August, a certain module pushed me over the edge. I bought a VisorPhone, which is a GSM phone module for the Visor. It included the Blazer PalmOS internet browser and some other cool free apps. So I was at an impasse — either buy a new Visor with more memory (the next model up, the Deluxe, contains 8MB), or stop using these modules and their included software.

Obvious choice, right?

But I’m a hacker, dangit! Surely there’s something I can do about my memory dilemma! Well, there was something. With some scavenging on the net for tidbits of wisdom (or recklessness, depending on your persuasion), I dug up some interesting data. A really excellent source of help and discussion is VisorCentral.

parts & tools

There are a few companies out there that will take apart your 2MB Visor and replace the internal DRAM with 8MB DRAM chips, or IC’s (Integrated Circuits) as they’re called. A couple such companies are:

  • STNE Corporation — they do mostly memory upgrades, and replacement color cases for Palm handhelds.
  • GetHighTech — they offer a whole line of replacement internal circuit boards, memory upgrades, and miscellaneous parts.

While these two companies offer great services, the inner hacker in me was determined to give this a shot myself. Plus, being an electrical engineer and just handy enough with a soldering iron to be dangerous, I thought I couldn’t lose. So after some more digging on the internet (thank God for Google!), I found the following crucial information, a sort of cookbook on the guts of the Visor:

1. Here is a list of DRAM chips recommended for upgrades (Note that memory architecture is mostly standard across the manufacturer landscape for both pin-out and functions. This makes the device selection rather easy, as it’s really only a matter of distributor availability.):

  • KM416V4104[ABC]S-L6 (Samsung)
  • uPD42S65165G5-A60 (NEC)
  • HM5165165LTT-6 (Hitachi)
  • MT4LC4M16R6TG-6S (Micron)
  • HY51VS65165CSLTC (Hyundai)
  • TMS465169P (Texas Instruments)

I chose to go with the Micron DRAM, since Avnet (a distributor) had plenty that I could sample (ahh, the fringe benefits of the engineering world!).

2. The next step was to download both the 2MB and 8MB datasheets and determine what was really different between them.

But I found that it wasn’t as “easy” as replacing one chip with another. There’s a significant difference between a 2MB chip and an 8MB chip. Their pin-outs are not alike — close, but not quite. However, Handspring was smart in designing only one set of Visor circuit boards (PCBs) for both the Solo and the Deluxe. With a “jumper” component(s) and the appropriate DRAM chip, a Solo can become a Deluxe during the assembly stage. Therefore, if we know the correct jumper configuration, we can turn our Solo into a Deluxe.

memory board & removed chip

In this case, the “jumper” components are zero ohm surface mount resistors. I removed the jumpers from positions R17, R21, R23, and R26 and put them in the vacant spots R16, R22, R24, and R25. Notice they are positioned in pairs: R16 & R17, R21 & R22, etc. However, the R19/R20 pair is not swapped. Relocating these jumpers allows the Visor to see the 8MB DRAM properly.

Here are two detailed pictures of my Visor internal boards and memory board.

boards, top

Sadly, after all this work, in less than three months, my Visor Solo-turned-Deluxe was dead. In the most inopportune of times, right after a car accident, the Visor and attached VisorPhone would not turn on. Despite fresh batteries and frequent “soft,” “warm,” and “hard” resets, the Visor exhibited strange memory crashes and instability. I concluded that my tampering had finally taken its toll, like so much bad medicine.

“Oh well,” I said. “Easy come, easy go.” Besides, this was the perfect excuse to upgrade to a Platinum!

Full Project Gallery:





21 responses to “Handspring Visor Memory Upgrade”

  1. jack Avatar

    Dear Rob
    Recently I found my sister’s visor solo in the garage where it has been sitting for almost 9 years!
    Yet it still works, however with 2mbs, I dont think there were any uses till I saw your website.
    Now I dont have a background in electronics / engineering, so I want to know if it is possible to do the same except with a larger memory?  Or will that be impossible?


    1. Rob Avatar

      Jack, yeah it would be possible to do. I no longer have access to the tools required to remove that SRAM chip and replace it with a new one however. I could put you in touch with a company that could do it for you however. I don’t know how much they would charge off-hand.

      1. Jack Avatar

        Yeah that will be nice!

        I thought I might give it a new lease on life cause no one is going to want a 2mb PDA 🙂


  2. zaklady bukmacherskie (Mr. Spammer) Avatar
    zaklady bukmacherskie (Mr. Spammer)

    HI dude, can i post articles to your blog ? Let me know if you are interested

    1. Rob Avatar

      No, you may not, Mr. Spammer. Your spam link has been removed. I win.

  3. Dini Avatar

    Hi Rob,
    I’d like to upgrade my 8 MB Prism to 16 MB. I recall hearing that it uses the same circuitry as the Visor Pro (which is 16 MB, that is, 2 x 8 MB chips), and those are easy to get from eBay. Could I just pluck the memory out of a cheap banged-up Pro and put them into my Prism, or do they need to be purchased (can they be?). I’m good at doing delicate things and not really scared to try, but I have no experience with this sort of thing. I know, the Prism is ancient but I like retro-Tech and am perfectly content with it, except the extra memory would be nice. I have two Prisms, otherwise I would not risk it. I googled for info but your site was about the only useful hit.


    1. Rob Avatar

      Dini, congrats to you for wanting to take this on. Modding stuff is fun! However, I should warn you that if you’ve never soldered before, your memory upgrade project will be a discouraging one to start with.

      The memory chips are — if memory serves (pun intended) — about 48 pins or so. That’s a lot of pins to desolder from a PCB without damaging the board. When I did my upgrade, I had access to what’s called a solder reflow machine. It made the process fairly painless.

      I personally wouldn’t attempt this mod with only a soldering iron.

      1. Dini Avatar

        Hi Rob,
        Thanks for the helpful reply. Yes, I did think this would be a fun project, which was the main motivation. But your comment plus the fact that there is so little info to be found on this (I did find some details on Palm upgrades, some of which were very complex!), makes me agree with you that it’s probably not a good idea to start with. Maybe I’ll find the needed chips and get them if they are cheap, as they should be, and when I retire in ~30 years and have more free time (and hopefully my hands are still steady), I’ll reconsider doing it. At one time there used to be reasonably-priced upgrade services for this exact upgrade, so it is probably very doable.


        1. Rob Avatar

          Yep, very doable indeed — with the right tools. And I agree with you. Paying to have the solder work done is the way to go. Some time ago, someone else such as yourself paid me to have a LCD flat panel connector repaired. I sent it to one of my contract manufacturers to have the work done with their automated solder machines.

          If you are interested, I could help you with that process.

          1. Dini Avatar

            I would definitely be interested except there is an eBay seller who sells Prisms that he upgrades himself — which makes sense, since it is riskier business to have customers send their own as in an upgrade service. He knows the condition of the Visor before he upgrades it. However, he had offered to upgrade mine at a very reasonable cost, so I was just contemplating doing it myself, for the experience and avoiding shipping my Prism. He is very honest (I had good experience with him), so I decided to ask him for the upgrade, in part based on your advice.

  4. bilety autokarowe Avatar
    bilety autokarowe

    After I originally commented I clicked the -Notify me when new comments are added- checkbox and now every time a comment is added I get four emails with the identical comment. Is there any way you may remove me from that service? Thanks!

    1. Rob Avatar

      This is the only comment I can find with the email address “Doose96@ruslanneck.de”. And according to this list, you’re a spammer.

  5. Dennis Hagans Avatar

    Hey Rob, I have two Visors and one Neo, I want the aaa battery pda, so the Neo with the 33 mhz and 3.5 palm os is great right now.

    The Visor pro is the last in the line but has 16 mb memory while my Neo only 8.

    do you think swapping cases could be doable? visor pro innards into a visor deluxe case, ditching the lithium ion for the conventional aaa batteries?

    I am handy with a soldering iron and could cut the existing aaa battery wires and the wires on the lithium ion battery splicing them together if need be. so that I end up with a Visor Pro running on aaa batteries.

    1. Rob Avatar

      Ooo, sounds like a tricky project. I’ve always found that enclosures are the hardest part of a project. Modifying them even more so.

      As to batteries, you have to at least match the capacity load of the target palm.

      Sounds like a fun passion project. Good luck!

      1. Dennis Hagans Avatar

        Thank you, I have bid on a 9.69 visor pro on eBay

        I am hoping the only difference will be the battery and the 16 MB memory.

        all of the visors look identical on the outside, same screen same buttons and arrangement, the Neo I have which is the model below the pro has aaa batteries and only 8 MB of ram, but the same look and the same 33 MHz CPU.

        I am thinking that the pro just upgraded the memory and went with a lith ion Battery.

        When I get it and delve into them I will report back.

  6. Dennis Hagans Avatar


    Visor hand held batt at cap Critical threshold

    Visor Neo 3.0 1.6

    Visor Pro 4.2 3.5

    This is not looking good, while the outside and certain functions are the same, the inside hardware is enough different that the voltages will not be right.

    1. Rob Avatar

      So you will soon have a Visor Pro which requires a 900mAH lithium ion pack and you want to use AAAs instead?

      First off, why? What’s wrong with the rechargeable pack? Regardless, keep in mind that a single new AAA battery is only about 1.5V.

      According to the Technical Reference, the minimum voltage (“critical threshold”, page 19) required in the Pro is 3.5V. Below that and the Springboard turns off and likely other bad things too. So given that minimum, you’d need at least 3 AAA batteries in series.

      The next concern is the current rating. Only alkaline are going to give you enough (1000mAh). In series, you don’t get any more capacity.


      Good luck!

  7. Dennis Hagans Avatar

    Hey Rob,

    I just won the Handspring visor pro on eBay for 9.69 and 11.23 shipping.

    I am going to try the switch to aaa batteries anyway, it may not come up or maybe it will but since I was all ready committed with a bid on the Visor Pro, I am going to give it a shot, it might even be that the terminals were kept the same so they did not have to change them on the mother board, and the aaa battery terminal will plug right in, if not I can do a quick cut and splice from the lith-ion battery wires to the aaa battery wires.

    I’ll let you know what happens when I get it in the mail.

  8. Dennis Hagans Avatar

    Hey Rob

    I got the Visor pro today and took one of my Visor Deluxe’s apart and realized that my assumption about the back plate was wrong I was expecting just a back plate with the battery cradle and a wire plug into the main board.

    Instead, there are two main boards one in the back plate which half of the dual battery terminal is connected directly to.

    I further read your attempt to upgrade a solo to a deluxe did not last long, I was looking to see if the memory board for the Visor Pro would go into the Visor Neo upgrading the Neo to 16 MB which would be perfect for me, as the Neo has the AAA batteries and the 33 MHZ CPU. as well as the palm os 3.5 etc…

    But after reading about your problems going from 2 MB to 8 MB and the unit dying, I am not so sure I want to try swapping memory modules and switching jumpers even if it is possible.

    Thank you for the replies.

  9. Dennis Kevin Hagans Avatar
    Dennis Kevin Hagans

    Hey Rob

    One more question for you, since you have taken one apart and worked on the inside.

    I noticed the memory module has a connector that plugs directly into the receiver on the board.

    I have the visor pro and the visor neo the only two differences is the neo has 8 mb ram and uses aaa batteries while the pro has 16 mb ram and a lion battery.

    do you think that it might be as simple as just swapping memory modules to make the Neo 16 mb ram?

    I know I am stuck on wanting to use the aaa batteries, my current visor pro lasts about 3 days on a charge and needs a new battery, which I have only found on e-bay for about 14.00 but the shipping is 45.00! from the UK.

    lions are in my humble opinion just plain bad for getting to the point where they do not last long and need recharging too often.

    I do like the energizer rechargeable batteries, they are not too expensive and if properly maintained will last many recharging cycles and they are a lot easier to replace than the visor pro battery lol.

    1. Rob Avatar

      I have no way to answer that one. This is such a long-defunct product, you’d be very hard pressed to find answers anywhere. Particularly when it comes to memory architecture and the like.

      I’d just be sure that the voltage rails are all the same, the pinouts are the same, etc. before swapping parts around. Once you’re sure you won’t “smoke” the part, then give it a try. What’s the worst that can happen?! 😮

      If the unit doesn’t recognize the new memory module, you’re likely out of luck, as there isn’t anyone left to write you a custom driver. 🙂

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