HP 200LX
HP 200LX is a pocket-sized PC XT compatible computer, 
		released in 1994. It has a software package in ROM: MS-DOS 5.0, Lotus 
		123 spreadsheet and PIm suite with calendar, organizer, plaintext and 
		formatted text editor, cardfile database, notetaking application and 
		some communication programs such as LapLink, Lotus ccMail or terminal. 
		200LX uses Intel Hornet processor which is a 7.91Mhz System-in-a-chip 
		device compatible with 80186 processor. It is powered by 2 AA cells, 
		rechargeable or not.
		In fact 200LX is not entirely compatible with PC, as for example PC 
		speaker is controlled with one channel, without frequency tuning 
		(required DAC was used to control battery), but there are workarounds of 
		it allowing even playing WAV files with 200LX's speaker, yet in poor 
		quality because of buzzer, low sampling and electromagnetic noise 
		inside. 
		Base 200LX unit has 1MB of RAM. There were 2MB units too, most LX had 
		connector allowing to expand memory with module up to 4MB, later even 
		64MB extensions were developed. Usually 640kB is used as DOS RAM when 
		the rest is going for RAM disk. 
		HP 200LX is still popular, there is a mailing list about it and some 
		people still use it. There was Minix port to 2MB unit but it offered 
		less than most Unix and is not maintained. 
		200LX is very durable, my unit fell once from about 1-1,25 meter to 
		concrete floor - PCMCIA card popped out, but the palmtop suffered only a 
		scratch in battery cover. 
| Manufacturer | Hewlett-Packard | |
| Origin | USA | |
| Year of unit | 1994 | |
| Year of introduction | 1994 | |
| Type | Pocket PC | |
| CPU | Intel Hornet (80186), 7.91MHz | |
| RAM | 1MB (640K + 352K RAM disk) | |
| Floppy Disk | None | |
| Hard Disk | None (possible to upgrade with PCMCIA) | |
| Other media | PCMCIA card | |
| Graphics and display: | CGA-compatible greyscale non-backlit LCD | |
| Sound: | PC Speaker (non-standard) | |
| Keyboard and pointing device: | Small keyboard with additional functions keys, Fn key, numeric part as the only way to enter numbers. | |
| OS: | MS-DOS 5.0, PAL (Palmtop Application Layer) Applications, Lotus 123 (all these in ROM) | |
| 
				 Power supply: 
				 1 - +12V DC, 1A PLEASE DO NOT CONNECT THEM WRONG WAY.  | 
			||
| I/O: |  - Serial port - Infrared (proprietary standard) - PCMCIA  | 
			|
| Possible upgrades: | Memory, changing quartz oscillator to overclock CPU. | |
| Additional peripherals: | Charger, DIY serial plug, PCMCIA CF reader with card. | 
I'm still using my LX in most situations as PIM, data collector (spreadsheet), notepad, ebook (TXT) reader, mathematical calculator and simple games device, and I usually have it in my pocket or bag. It has two big advantages which are absent in today's devices: One: It works on one charge of batteries for few weeks (I'm using Sanyo Eneloops), Two: It doesn't spy the user as every today's device with communications chip (these chips are never turned off, they may be disabled by software, but they may perform some operations even when disabled).
HP still offers User's Guide for 200LX to download. Get it and see if you plan to use LX.
| Contents: | First steps | Typical problems | Useful programs | Own codepage | Easter eggs | Serial port | Links | 
If you've never had a HPLX:  RAM disk is C:. If you 
		put a CF card in PCMCIA, it becomes A: drive, not D: (ROM disk is D:). 
		Its speed is only a little higher than floppy drive, but it's 
		non-volatile so it's good to save RAM disk for example for DOS swap file 
		(see MaxDOS) and keep documents and programs in A:.
		Second thing: EXM files are programs which can be run from System 
		Manager after creating their icon.
		Third thing: If you put a " after program and number there, this is 
		memory allocated to program, for example when path in system manager is:
		A:\PROG\BATTRY\ABC.EXE|120
		Then 120K will be used for this program giving more memory for System 
		Manager programs.
To make locale work, you need to extract locale kit files (hp200lx.kit and hp200lx.fon) from ROM to root of RAM drive files using supplied software and use KEYBEZ to set keyboard and locale (for example keybez pl - Polish keyboard and character set). Useful hack to save RAM disk space needed for these files is described here.
Don't forget to look at hacks page which has some hacks for HP LX.
I recommend to copy AUTOEXEC to CF card and get rid of unneeded TSRs such as LapLink, CIC TSR or card assigning, they consume memory which may be used for better purposes.
One more thing. I think you know that there is a RAM support battery near IR port, it's a normal CR 2032. It rarely requires replacing if AA main batteries are running.
Hinges. If your LX hasn't broken hinges, you should 
		prevent breaking by loosening right one. I know it's  not looking 
		good, but if you don't want to break hinges you must make it loose, 
		optimally to let the lid open by itself VERY slowly when left opened at 
		~135 degree angle. 
		Right hinge contains most of tightening  mechanics. Open palmtop 90 
		degrees and remove right hinge cap, it should come off only using 
		fingernails. Now use small amounts of lubricant to loose the hinge. 
		SMALL AMOUNTS - less than a drop, it's good to use piece of paper rolled 
		to a small tube to apply it. Every application open and close palmtop a 
		few times to check. It's better when it's too loose than too tight, but 
		if you want to tighten it, apply alcohol instead of lubrication.
		Never take right hinge apart. I have no idea how to put the spring-cone 
		assembly back without telekinesis.
If you charge batteries, your LCD will temporarily loose contrast. It's normal. LCD's contrast depends on temperature, LX has temperature sensor to compensate it. When you charge LX, temperature inside rises and sensor tries to compensate it, but LCD is still in room temperature. Just wait after charging to cool it down and it'll be back.
Icon from another directory - if you add icon, you have quite limited icon range, as it looks in program's directory and in ROM. This program deals with the problem. Readme says about MoreEXM launcher, but for deafult one JUST CREATE ICON for selicn.exm, make its shortcut key and use it when setting another icon. Launcher should pop out and you can select an icon.
Here I'll describe what software I'm using. Everything 
		works from 64MB ComactFlash card, and I never use more than 40MB on it.
		Shareware/freeware programs which could be found on former SUPER library 
		will be placed here for archival purposes. SUPER library may come back, 
		but I don't know when.
		These are programs other than these found in LX's ROM, a very good PIM, 
		calendar, task list, contact list, database, Lotus 1-2-3 spreadsheet and 
		some other programs.
True DOS: MaxDOS
		This program will make DOS session with maximum available memory, but 
		without switching between PAL programs. Needed for some games or big 
		programs. You need to modify your AUTOEXEC.BAT properly: Add this before 
		running of System Manager (200 or 100):
		A:\PATHTO\MAXDOS.EXE -L -E25 -WC:
		WHERE:
		A:\PATHTO\MAXDOS.EXE - self-explainatory
		-L - Load driver
		-E25 - use 25 pages of swap file
		-WC: - swap file will be used in C drive 
		(RAM disk), taking ~235kB. Better place it in RAM drive or it'll start 
		really slow.
		TO RUN PROGRAM FROM PROGRAM MANAGER:
		In Path of entry instead of:
		A:\PROG\MYPROG.EXE|
		type:
		A:\PATHTO\MAXDOS.EXE A:\PROG\MYPROG.EXE|
		Let's create shortcut for pure-MaxDOS session. Path is:
		A:\PATHTO\MAXDOS.EXE|
		To use it as DOS shortcut, you should give it a title "MAX-&DOS" 
		and place it in front of normal DOS icon to be the first icon of D 
		shortcut.
DOS Programs Manager: HDM 
		Launcher
		Must-have if you use many programs, as LX's program manager is somewhat 
		limited to 32 icons. Just place an icon to HDM Launcher (using MaxDOS as 
		stated above) and you have more space for DOS programs.
		
Key assignments: ExKey
		You want to assign function keys to what you want or swap some of them? 
		Use this small program! You must run it from Autoexec.bat before System 
		Manager, the way as follows:
		A:\PATHTO\EXKEY.COM -fA:\PATHTO\EXKEY.INI
		Some samples of EXKEY.INI lines:
		{Filer}={ctrl+123} - if you don't use Filer, this command uses Filer key 
		to swap to running DOS program (DOS session button is configured as 
		Ctrl-123). Useful.
		{cc:Mail}={ctrl+Memo} - if you don't use Quicken, after using this combo 
		Quicken key will be used to run NoteTaker.
		Genearlly {Pressed Key}={Effect}
| Task manager: Tasklist Very useful, especially if you want to save memory: Here's a trick: After you run System Manager, run this task manager and CLOSE (F5) Filer process. This will free the memory. Filer is always loading at boot-up and if you don't use RAM disk, you can remove it from memory. If you use RAM disk only, Filer in RAM is needed if you run out of RAMdisk and need to move/delete some files.  | 
				
E-book reader: VertRead (shareware 
		version) (Polish 
		fonts) [Author's page]
		This program can display ebooks in vertical form, so you can hold 
		palmtop as a book while reading. It supports TXT format, all e-books 
		should be converted to it. Well, this is good when you read in a bus.
Maths: Derive 4
		This is a full-featured algebra package for DOS, something like today's 
		Maxima. It allows me to quickly solve differential and integral 
		problems. Unfortunately it's commercial and open alternatives require 
		thousand times faster CPU and bigger RAM.
Remote: Remote Commander (shareware 
		version)
		This small app uses LX's infrared adapter to work as universal remote 
		controller. Its operating range is not big, but it works nicely to 
		control TV and DVD with one device. You have to teach it signals from 
		existing remote then it replays them.
		
| Battery: ABC/LX (shareware 
		version) [Manufacturer's site] This program allows to display battery voltage in screen corner (it works as battery charge indicator) and controls charging process by displaying voltage graph. It works with cells up to 1600mAh, so to charge for example 2000mAh (about 19 hours with LX fast charging) battery, you have to charge for 16 hours and then for 3. Remember to add ABCTSR.COM to Autoexec.bat before System Manager.  | 
				
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Periodic table of elements:  
		simple, advanced,
		more advanced
		I have all 3 in my unit, but I'm using simple one, as it takes less 
		memory I can use for spreadsheet, which I'm using together with table. 
		TABLE2 is normal, TABLE3 has Polish element names.
Alarm Clock: HP Alarm clock
		Just a simple alarm clock! A bit different sound as in Appointment 
		Manager, easier to hear.
Measuring ruler: Scale/LX
		Very useful. Just run it and you'll have a ruler on your screen to 
		measure things. You can place it "negatively" to start with beginning of 
		palmtop's lid, not the screen.
		
Drawing: PALDraw
		Maybe you think that it's stupid to draw with cursor keys. Well, if you 
		get used to this program, you can do simple technical drawings without 
		problems. You can freely register program on
		developer's site.
Font editor: PFE
		You want to localize fonts for Vertical Reader or WWW/LX browser? This 
		application allows you to do it.
Icon editor and browser: 
		ICNEDIT
		Self-explainatory.
| At the end... My Cthulhu wallpaper :). If you download it and you have inverted colors - LX displays it negative, it's normal. | ![]()  | 
			
Games which will work:
		 - SimCity 1 (commercial) - can be driven with cursor keys. 
		Well, it's good for boring lectures :D
 - Nice Tetris clone - works in text mode!
 - Castle (simple ASCII pseudo Rogue) If you stand 
		its instabilities and glitches.
 - Most CGA XT games will work.
It's possible to make your own codepage with keyboard definition and font by manipulating values in locale kit files, I don't remember exactly how, but these were nicely documented/commented text files. I've modified Polish codepage to fit some mathematical symbols needed in engineering DOS programs, so I could enter them in documents by pressing key combinations such as Fn-J (gave integral symbol in my programs).
Easter eggs are hidden demonstration functions in a program, usually introduced by development team without knowledge of their company. It's similar to scratching "xxxx WAS HERE" on a wall in some place. LX has few of these and they'll be described here:
| 
				 Lair of Squid game gallery: 
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Hexcalc - hidden application
		Make an icon with path: D:\BIN\HEXCALC.EXM. 
More applications
		Press "&...", applications menu will appear. Hold ALT and press F9 4 
		times, then F10 once. Until ALT is presset, you'll get technical info 
		about System Manager's icons.
 [1 2 3 4 5 ] [12V DC 
		jack]
 [6 7 8 9 10]
1 - DcD
		2 - Rx
		3 - Tx
		4 - DTR
		5 - GND
		6 - DSR
		7 - RtS
		8 - CtS
		9 - RI
		10 - Shield ground
Notice that by soldering simple PCB you can make HP LX - DB9 converter:
		http://www.hermocom.com/en/knowledgebase/hplx - Everything you 
		wanted to know about HP LX.
		
		http://www.upl.cs.wisc.edu/~orn/tech/200lx.html - Memory upgrade
		
		http://web.archive.org/web/19970707031653/http://coyote.accessnv.com/davidsa/hp/inside.htm 
		- Detailed disassembly. I recommend using disassembly instructions not 
		to break your LX.
		http://www.palmtoppaper.com/ 
		- Palmtop Paper - Articles about palmtops, mostly LX.
		http://www.hplx.net/ - more articles, 
		how to disassemble, etc.
		
		http://www.hplx.net/hardware.pictures.html - Good resolution photos 
		of 200LX internals
		
		http://web.archive.org/web/20030423184106/http://minix.technoir.org/ 
		- Archived copy of DOWNLOADABLE Minix for LX images
		http://palmtop.cosi.com.pl/
		- Blog about old palmtop computers