"Thanks for the Memory" (Cards)

They used to store, at most, 1MB of data and cost more than $500 a megabyte. Now Flash cards with file compression software can store up to 20MB of data and cost as little as $50 a megabyte.

By Mark Scardina

One year ago we looked at RAM cards for the HP 95LX. Due to the many developments of this past year, I believe it's time that we re-examine this area.

The HP 95LX was designed prior to the development of uniform standards for RAM cards. The development of these standards was the responsibility of a nonprofit group called the PCMCIA. Since HP is on this committee, the 95LX ultimately was compatible with the initial uniform standards (PCMCIA 1.0 standards) released in 1991. Since then, there has been a release of updated specifications (PCMCIA 2.0). The new standards allow for the development of cardbased modems, network adapters, and wireless links. The 95LX is not able to use the new PCMCIA 2.0 cards.

The PCMCIA standard number should not be confused with the "type" specification, which refers to the thickness of a card. Initially, RAM cards were 3.5mm thick. These have been given the designation of "Type 1." There now are two additional types: Type 2 (5mm thick) and Type 3 ( 10mm thick). Your 95LX can physically handle Type 1 and 2 sizes, not Type 3. (Remember, Type 2 can be used on the 95LX, PCMCIA 2.0 cards cannot!)

With one exception, which I will get to later, the only function that you can use PCMCIA 1.0 cards for on the 95LX is file storage. There are currently three technologies available that can be used by the 95LX. These are Read-Only-Memory (ROM) cards, Static-Random-Addressable-Memory (SRAM) cards, and Flash-Random-Addressable (Flash RAM) cards. There is another type of memory card technology call Dynamic-Random-Addressable-Memory (DRAM). DRAM cards are used on many laptop and notebook computers, but DRAM cards cannot be used by the 95LX.

Read-Only-Memory (ROM) Cards Graphic

 ROM cards have been available since before the introduction of the 95LX. They are the least expensive form of memory card, but are read-only and cannot be written to. ROM cards are most suitable for storing software programs or data files that do not need to be changed.

A software program on a ROM card can be installed simply by inserting the card into the 95LX, eliminating the need of a disk drive or file transfer from another computer. The ACE Gamecard, Personal Food Analyst, Derive, HP's Dictionary/ Thesaurus card, and the Global Translation card are examples of software programs on ROM cards. Most 95LX software is not available in this form because the card cost is 50 to 100 times that of a floppy disk.

ROM cards are more stable than their writeable counterparts. The software program is "etched" permanently into the card's microchips and can never be altered or lost through any action, short of physically destroying the card.

Static-Random-Addressable Memory (SRAM) Cards

SRAM cards are the most popular card storage technology used on the 95LX -- and it's becoming less expensive. While SRAM cards are still very expensive when compared to floppy and hard disk technology, SRAM prices have plummeted by almost 70% in the past year (from $500 per megabyte to $180).

SRAM's only other disadvantage is that its memory is retained by the presence of a battery. The lithium backup batteries used in the cards provide a one year life. However, there is a problem with this on the 95LX.

The earlier versions of SRAM cards sent exact data on the level of the backup battery to one of the pins in the card. The 95LX has circuitry to enable it to interpret this voltage and give you a warning in time to change the card's backup battery before it dies. Current SRAM cards, including HP's cards, have this battery level circuitry built-in and only report one of three conditions -- OK, Warning, and Data Not Guaranteed. Unfortunately, the "Warning" indication cannot be read by your 95LX because the pin is not hooked up. This means that when you get the "Card Battery Low" warning it may already be too late. (This means that BATTCK.COM (ON DISK ICON) on the 1992 Subscribers Disk, should not be relied upon to report the status of the RAM card battery.)

The recommended procedure with SRAM cards is to change the battery every 11 months. Set an 11-month reminder in APPT and change the battery whether you've received a low battery warning or not.

When your 95LX is off, it sends no power to the card. This occurs when you turn the 95LX off by pressing (OFF) or when the 95LX automatically shuts off after three minutes. If you do get a low battery warning, do not turn off your 95LX! Connect your Palmtop to the AC adapter so your 95LX doesn't "time-out" and change the battery. If you don't have an AC adapter handy, press a key every three minutes until you can change the battery. (You can also disable it from timing out with TIMEOUT.COM (ON DISK ICON).)

SRAM cards do have advantages. First, they're the fastest of all the memory cards, especially when writing to them. Next, they have virtually an infinite life with no drop off of performance over time. They also are both readable and bootable without the need of additional software. This is a distinct advantage on the 95LX as it is possible to lose the data and programs on your C: drive. Since a SRAM card can always be read, you can keep your startup files (CONFIG.SYS and AUTOEXEC.BAT) on it and boot from the SRAM card to recover from a C drive crash (insert the SRAM card in the slot and press (CTRL)-(ALT)-(DEL)). Finally, SRAM cards can be easily interchanged among other computers with RAM card slots that support any level of the PCMCIA standard. Memory Card drives are available that connect to your desktop or portable computer and allow them to access your card's data quickly.

The largest SRAM or ROM cards available are 2MB. ACE Technologies has incorporated software into their SRAM cards and increased this limit 8MB (though the price per megabyte is currently higher).

Flash-Random-Addressable (Flash RAM) Cards Graphic

 The third type of memory card technology is Flash RAM. Flash RAM has the ROM advantages of not needing a battery to retain its data, and the SRAM advantages of being writeable.

The implementation of different Flash RAM cards vary. Sundisk was the first company to introduce a writeable Flash RAM card for the 95LX. These cards conform to a supplemental PCMCIA-ATA standard that allows them to appear as more conventional IDE hard drives to the 95LX or a PC. This has the advantage of raising the upper limit on capacity to the full 32M available under DOS 3.22 on the 95LX. Due to physical constraints, the maximum size currently available is 10MB (20M using compression software). This yields the cheapest cost-per-megabyte for high storage capacities.

While Sundisk has achieved a tremendous technological feat, its cards have some disadvantages. First, the card is not readable or bootable without a "device driver" (small software program) already running on the 95LX. This is not much of a problem, unless your 95LX's C drive corrupts or is otherwise lost. Sundisk users might want to carry an additional SRAM card with the files necessary to reinstall the Sundisk device driver -- just in case!

Sundisk provides a serial cable and software to transfer the device driver software between a desktop or portable PC (286 or better, no Macs) and the 95LX. The Sundisk cards are marketed under the "Altec Electronics" label in Germany. When you purchase a Sundisk card from Altec, you get an additional ROM card with the device driver on it, making it easier to install. (As we go to press, ACE Technologies has announced their version of the Sundisk card, to be called the "DoubleFlash Card." The ACE card will also include the device driver on a ROM card.)

It should be noted that the device driver used is specific to the HP 95LX. If you want to use the Sundisk card in another notebook's or desktop's memory card drive, you have to first get the appropriate device driver. At this time only the 95LX driver is available. Databook and Zeos drivers have been announced. Additionally, AMI and Phoenix have announced device driver availability as a BIOS option. This will allow newer palmtops to read these cards without having to install a device driver.

Flash RAM cards, while having a virtually unlimited read life, have a limited write life. That means that there is no limit on how many times you can access data. However, there might be a limit on how many times you can change data. Flash RAM write life has been greatly increased through improvements in the memory chips used in the cards and software incorporated to detect failing sectors. Claims have been made that a typical user need never worry about losing data due to a write life problem. However, I think that unless the card supplier is willing to back up this claim with at least a five-year warranty, SRAM cards may be safer. (At the time of this writing, Sundisk provides a one year warranty, which they may revise upwards. ACE has announced a lifetime warranty on its Flash RAM card.)

Finally, it takes a little bit longer to write to a Flash RAM card than it does to a SRAM card. This is because it takes a small amount of time for a Flash RAM card's write circuitry to come out of its "sleep" mode (necessary to allow the card to have similar power consumption as a SRAM card). I did not notice this additional write time in my daily use.

Flash RAM will shortly be available in a SRAM-type configuration. This will allow the Flash RAM card to be readable and bootable, without installing additional software on the computer. (The required device driver will reside on the card itself instead of the 95LX's C drive.)

These new Flash RAM cards will suffer the same storage capacity limitations as SRAM (2MB). The cards will be cheaper than their ATA counterparts due to less hardware being required for use within the card. ACE Technologies has announced the availability of these cards later this Spring.

FAX / Modem on a Card Graphic

At the top of this article, I mentioned that there was one exception to the "storage only" use for 95LX cards. New Media has recently begun shipping its PalmModem card, a PCMCIA 1.0 device which works on the 95LX by virtue of a special device driver.

The New Media PalmModem is a fully functional 2400 bps modem and facsimile machine. The card contains both fax and modem circuitry as well as communications and fax software in ROM. The PalmModem needs only to be inserted into the HP 95LX. One end of the PalmModem cable plugs into the PalmModem. A standard telephone cord plugs into the other end.

 Is Compression Software Desirable?

ACE Double Cards:  Graphic

 The answer seems to be an obvious , "Yes." The additional cost of such software has been reduced of late and, and the software has become very reliable. However, CPU processing time is an important consideration. (Compression software such as DIET, ACE Double Card software, and Stacker can on average double the amount of storage space available on your RAM card. These programs have been discussed in past issues of The HP Palmtop Paper.)

A program like Stacker has to do a lot of CPU processing to copy and save files. On most desktop computers, you don't notice this because the CPU on a 386 or 486 is faster than the hard drive you're writing to.

The 95LX is an XT-class machine with a slow CPU. However, its RAM disk is extremely fast compared to a hard disk. A compression program like Stacker on the 95LX slows down the access time to a RAM card as compared to an un-Stacked card. The result is that, if you routinely save large (100K+) files on a Stacked RAM card, your save times will increase by a factor of 10.

You should also realize that the advertised doubling of disk capacity is only an estimate. If you are planning on storing large numbers of program files (.EXE or .COM), you will probably see only a 50% increase. On the other hand, large worksheet or text files are highly compressible and a threefold increase is not uncommon when compressing these.


PCMCIA 2.0 is the new standard for memory cards. Future PCs with card drives, including any successor to the 95LX, will most likely have PCMCIA 2.0 drives. The PCMCIA 2.0 standard allows the development of modem, network, or wireless link cards, and many may consider upgrading to any 95LX successor to access these options.

One small point to remember is that the 95LX has only one memory slot. If you want to send a file using the New Media fax/modem card mentioned above, you first have to copy the file to your 95LX's C drive. You can't have the file on your RAM card because you're going to remove that to insert the modem card (or whatever). This is not much of a problem, unless the file is large, and you don't have enough room on your 95LX's C drive.

One final point. You can use PCMCIA 2.0 memory cards in a 95LX. PCMCIA 2.0 I/O cards (modem, wireless, etc..) will not work.