Epson PX-8

[Rockin' Kat]

Hi,

I found an Epson PX-8 with an Epson PF-10 floppy drive, and a special piggy back kind of add on called Epson Multi Unit 64(which appears to add a modem... and get's it's power from the PX-8 ) about a month or so ago.

I was able to find some new AC adaptors that meet the ratings on these things at RadioShack(cost more than the computer and drive)... the floppy drive's power light comes on...

But the computer shows no signs of life... It has ROM's in all exposable sockets, and the battery pack in too.

Does this thing need a good battery pack to run at all?

Pictures can be found here:

http://www.thecowsaysmoo.org/superpsycho/Pictures/thrift/july06/epsonpx8/
note: at time of posting the site isn't responding... but that is the correct url... eventually it should work... as long as things havn't gone completely belly up.

[Terry Yager]

The early Epson laptops run only from the battery. The external 'charger' is just that, a charger. It won't turn on at all unless the battery has at least a small charge. The cells in the battery pack are standard 'sub-C' cells, available at RadioShack, for around $25.00 for the four you'll need. If ya need help, I'll gladly build ya a new pack, just for cost. (Mine, with new cells, lasts for 20 - 25 hours to a charge). There is also a small, internal battery pack, which must be charged to function correctly. I've replaced mine with a 4-part AAA pack, so I can fill it with NiCads. Also, the Multi-Unit has it's own battery pack (4 x AA NiCads).

--T

[Terry Yager]

Oh, yeah...the Multi-Unit 64 is an add-on that combines a 300-baud modem, an extra ROM socket, and a 64K RAM disk, which frees-up main memory for use by your apps. See also this article:

http://www.vintage-computer.com/vcforum/showthread.php?t=1024

--T

[Micom 2000]

Hey T, could this be a new venture now that "computer Hell" is gone ? I for one am fed up with the inflated charges that most of these LT Battery charge. I'd bet that just supplying the needs of this forum alone would necessitate hiring employees.

The early Epson laptops run only from the battery. The external 'charger' is just that, a charger. It won't turn on at all unless the battery has at least a small charge. The cells in the battery pack are standard 'sub-C' cells, available at RadioShack, for around $25.00 for the four you'll need. If ya need help, I'll gladly build ya a new pack, just for cost. (Mine, with new cells, lasts for 20 - 25 hours to a charge).

--T

[Terry Yager]

No, it's just that it takes, like, 10 minutes to throw together a pack of four cells with solder tabs. I don't mind helping-out someone who is unable/willing to do-it-themself. (Especially if they're trying to resurect my all-time-favorite computer, the PX-8).

--T

[Terry Yager]

Oh, BTW, as of today, CH is back. The building's owner and have agreed that the stuph is officially abandoned by the buyer, so I should be able to dig out a few more treasures, but from here on, it'll be considered a scrap/recycling operation (I've found a scrapper who'll clear it all out for free, vs the $3,000.00 estimate the trash haulers want). Hell, I'm half tempted to scrap it out myself, after seeing what electronics gold scrap is selling for on daBay these dayz.

--T

[Terry Yager]

Ummn, if you're using an off-the-shelf charger, be sure that the polarity is correct. Most wall-warts I've seen have the center-pin positive (+), but the Epsons are backwards, with the center negative (-).

--T

[DoctorPepper]

Hey Terry,

I don't know if you've seen this yet (I stumbled across it today during a Google search for information on Packet Radio with the TRS-80 Model 100), but it was too good of a deal to pass up:

http://www.notebooksupplies.com/epson/px8.html

You can still get PX-8's, brand new in the box, only 24 years old!

[Rockin' Kat]

Coming back a little late here...

I know my charger has correct polarity... it can be changed by removing the plug and putting it on reversed... and I've set it to what it needs... the battery is probably just shot to hell since it's so old....

I think I'm going to take a stab at building my own battery pack.


....I wonder how hard it'd be to find a replacement for hte keyboard slide cover since I wasn't fortunant enough to get it with that.

[Terry Yager]

Coming back a little late here...

I know my charger has correct polarity... it can be changed by removing the plug and putting it on reversed... and I've set it to what it needs... the battery is probably just shot to hell since it's so old....

I think I'm going to take a stab at building my own battery pack.


....I wonder how hard it'd be to find a replacement for hte keyboard slide cover since I wasn't fortunant enough to get it with that.

I have an extra keyboard cover, just not sure where it's stored. If I can find it, you're welcome to it.

The battery pack is a cinch to do. You can get sub-C cells with solder tabs at RadioShack.

--T

[Rockin' Kat]

I have an extra keyboard cover, just not sure where it's stored. If I can find it, you're welcome to it.
--T

Well if you find it I'd really like to buy it from you.

[Terry Yager]

Well if you find it I'd really like to buy it from you.

I did look, but it ain't where I thought it might be. It should turn up sometime.

--T

[Rockin' Kat]

Oh, I know how that works. When I first got my Amiga 2000 I bought some cards....

one of these cards was a flickerfixer/scan doubler for using VGA monitors with the computer... but I never quite got around to installing a lot of the stuff as I was trying to find an accelerator for the computer...and when I could not find one for sale... I decided to just install what I had.... but I could not find the flickerfixer/scandoubler... This infuriated me.. I knew just where I put it... and it was not there....

Months went on... I still hadn't actually found the accelerator I wanted... so I gave up and sold the computer(bought a 1200 in it's place, already upgraded with an accelerator)... well... about 3 months later.. I was looking through my dad's supplies in the den and I found my flickerfixer/scandoubler in the box for a printer that my mother had brought home because it came with the computer my grandma got, and she didn't want it... so now I have a flickerfixer/scandoubler that is intended for the 2000 and I have no Amiga 2000. Bah.

[Sharkonwheels]

Hey Terry,

I don't know if you've seen this yet (I stumbled across it today during a Google search for information on Packet Radio with the TRS-80 Model 100), but it was too good of a deal to pass up:

http://www.notebooksupplies.com/epson/px8.html

You can still get PX-8's, brand new in the box, only 24 years old!

Yo, DP! Want another TNC? I have an MFJ 1270 you're welcome to for shipping cost. DOn;t know anything about it, no PSU, but MFJ's I think are all the same.

I used to use (early 90's) an MFJ 1278BT,with a Kenwood mobile in the house.


Tony

[Sharkonwheels]

Yo Chuck - you think one of these floppies can be built?
From what I've read, the floppies have a tiny z80 computer, loads a mini-os, and then serves the floppy over serial, which I guess is how px8vfs can emulate it.

think we can build a beast like it? Since SuperPsycho has one, we can dump the ROM it has....wonder how hard it'd be to duplicate the cpu board?


Tony

[chuckcmagee]

You have WAY more ambition than I got. I have enough to do with replacing motherboards and rebuilding LCDs. Oh ya, and sending Toshibas back to the f'n factory to get the static lockup problems fixed (I have 2 Toshibas that both lockup, known design flaw with that model, sure wish I had known before I purchased them on ebay). Same toshibas also have dc jack that's breaking every 2 months. Sorry I ever looked at them. They were the "cadillac" of the laptop line at one time, no more.

[Sharkonwheels]

You know what's looking REALLY good these days? The HP/Compaq laptops. Dozens of my co-workers have bought them, and noone has a complaint yet.

I'm JUST about ready to pull the trigger.

You can get anything from 12.1" to 17", adn anything from a celery, i mean celeron :) up to a dual core AMD or Intel. decent warranty, low DOA rates, so-so support.

Let's face it - who doesn't have ot-sourced support nowadays?
You call/email/chat and get "thomas" but the email address is :

mufuakkabalaamoskinpriote@india.dell.com or some such nonsense.


Back to the PX-8 :D

Think it's doable?


Tony

[chuckcmagee]

If I was SUPER motivated, maybe could pull it off but using vfloppy on a laptop just isn't that hard or that much trouble.

Reminds me of one of my bosses of old. I talked him into letting me modify the existing COBOL compiler (in assembler, mind you) to make coding programs faster. It took me 6 solid months of 13 hour days to get it all done and working. He never, EVER, recovered the time I spent in saved man hours using the resulting compiler. I rest my case. Sorta like doing a disk defrag - I don't think you ever get that time back in increased performance.

[Paisley Pirate]

Hello everyone!

I was doing some cleaning and came across my old PX8 "collection" that has been sitting filed away (literally) for a few years.

I pulled it all out, plugged them in, and they all still came up to enough charge to run!

Anyway, I haven't messed with them in forever, and I'd like to sell them. I will list the whole mess in the for sale section, but I do want them to go to someone who will use them and enjoy them!

[detnyre]

I received a Kenwood TD-D7A hand held 2 meter radio that has built in TNC. This weekend I'm going to create a cable to connect it to my PX-8 - should be easy to do.

Does anyone have any advise for setting up the PX-8's terminal program to run TNC? I assume it should be straight forward to do.

Once configured and working, this should be a fun setup to use.

I hope it will be warm enough here in Tampa, FL to sit outside on the picnic table and work with it....

Derek

[detnyre]

Hi,

I have one working PX-8 and one that is dead. I took the rom chips and battery from the working PX-8 and installed them in the non-working one, made sure all of the switches were in same positions and still no go. Does anyone have any suggestions for other things that cause the laptops to stop working. www.notebooksupplies.com sells replacement motherboards for these - but want to make sure I'm not overlooking the obvious before I spend the $75.00....

Derek Etnyre
detnyre@mac.com

[Terry Yager]

I have a working spare. Pm me...

--T

[chuckcmagee]

http://www.notebooksupplies.com/epson/px8.html

Don't know if you noticed but same place sells the entire thing NEW for $79.00 plus shipping. When I got mine from there, turned on the internal backup power switch and charged it up for a few minutes. Works perfect, those ancient Ni-Cads even hold a charge.

Only thing I don't like about that guy is he takes the User's Manual out of the "New Old Stock" box and resells them for $12.95 or something. I wasn't real happy with that trick.

[EvanK]

http://www.notebooksupplies.com/epson/px8.html

Screw that guy. He's selling a used ("refurbished") HX-20 for $389 and he's got the nerve to list it as a "discount price." On ebay these things go for $50 tops, usually less. He wants $499 for a used one with the tape drive. Geez, I'll sell you one with the tape drive for half that price. :)

His other prices are equally stupid. He probably hangs out with the ebay seller "Computermkt" that we've been laughing about in disbelief over on cctalk.

[mbbrutman]

Come on Evan, tell us what you really feel about his prices. ;-)

[Terry Yager]

I have to agree about most of the prices, but eighty buck$ for a NOS PX-8 don't sound so bad. I'd prolly buy one for myself, if I wasn't so attached to the ol' beat-up one I have now (we've bonded).

--T

[Sharkonwheels]

yeah - but what you guys don;t realize, is that there are still places that use the HX-20, for example, older cruise ships that have the old Ving punch-card plastic stateroom keys, use an HX-20 to drive the puncher.

I don't know about most businesses, but i don't see cruise lines buying on ebay - that's just not going to happen.
That's just one use - I know there are others, and they are still being used.

That brings up the supply-and-semand thingie....

I, myself, would do what others have said, and hang out on ebay and get one there.


Tony

[detnyre]

I purchased my first PX-8 from notebooksupply - it was worth the extra cash for one that was NIB. The first one I received did not work, and they promptly exchanged it for one that worked. In exchange for sending back the non-working px-8, they sent me some additional books and manual. I think his practice of removing and selling the manuals is crappy, but besides that the deal was decent.

My second, and non-functioning, PX-8 was purchased on ebay as part of a lot that included the modem wedge, thermal printer, dbase and wordstar rom chips.

Does anyone have any use for a non-functioning PX-8? If you pay for shipping or pick it up in person in the Tampa, FL area - you can have it for free. I just can't bring myself to throw it away, but i don't have room for it in my motor home.

Derek

[Terry Yager]

If you have the means to copy the dBase ROM, I'd like one.

--T

[Terry Yager]

There are still a lot of HX-20s (with RealVoice) in use among the hard-of-hearing community. They can be had a lot cheaper than more modern adaptive technology.

--T

[Terry Yager]

Oh yeah, for non-functioning PX-8s, try the internal backup battery. If it's incapable of taking a charge, the PX-8 won't start up at all. (I've replaced mine with a 4x AAA-cell pack, populated with NiCads from RadioShack.

--T

[detnyre]

I took the rom chips and battery directly from a functional PX-8 and put it in the one that is not working and it still does not work.

When I turn it on the LCD screen turns blue so know it is getting power, it just does not boot up.

If anyone would like the non-working PX-8 for parts or to see if you can get it to work - send me a PM. You can have it for the cost of shipping.

Derek

[AccordGuy]

I found a couple of PX-8s at a car boot sale at the weekend (sorta like you call a yard sale in the US but in a farmers field)... anyway... this woman had two Swedish PX-8s (one still in the box with all the manuals & ROMs) so I bought it but I'm having trouble getting the thing started.

I know about the two batteries and on opening the thing the internal pack seemed dead and wouldn't take a charge. I cut it out and gave it a blast on the bench PSU (probably some internally shorted cells) & now it works ok - it holds a charge of 5v. The main battery seems ok too - holds about 5v.

The problem is that most of the time the unit starts and asks if I want to "Reformat the RAM drive A: ? (Y/N)" and then immediately comes up with a "BDOS error writing to disk: File R/O" and then hangs.

With both the battery packs out I ran the machine from a bench PSU set to 4.5v and it said "CHARGE BATTERY" and turned off, so I progressively cranked the PSU to 6.0v and the machine sprang into life and did it's init routine (set time/day, RAM disk size, etc.) and went to the CP/M menu. I ran CONFIG, STAT and BASIC ok. Then I put the (now externally charged) batteries back in (had to solder the internal one back in) and when it starts all I get is the old "BDOS error writing to disk A: File R/O" routine again...

For those who have had to replace the batteries before, is this how the machine generally behaves when the packs are nearly shot?

It looks like a very cool machine and I'd love to show it off if I can get the thing to tick :D

AccordGuy

[Sharkonwheels]

Hmmm....isn;t there a RAM protect switch in that jumper block under one of the covers? I THINK one of the switches it a write-protect...


Tony

[AccordGuy]

Playing with it again this evening, I managed to get it to start up again a couple of times by taking the main battery out, turning the backup battery off and doing a few full init resets with the button under the cover and then turning on the power switch with the external PSU at 4.5v.

I then turned the backup battery back on and did the full reset again and it goes into the "CHARGE BATTERY" message. After that I increase the external power to 6v and turn on and this time I get the init routine and CP/M comes up.

If I get that far, I can then put the main battery back in and use the thing on either external 6v or the main battery. It turns off and on ok and the clock / calendar is maintained.

It's very flakey though - crashes all the time when working (took several goes to get BASIC to load and initialise). A soft reset (left side button) brings you back to CP/M menu (usually, but sometimes gets stuck reading the directories).

So far it's worked just long enough between crashes for me to write and run a "hello world" program with 5 loops before it bailed out completely and started the "Reformat drive A: (Y/N)" nonsense again...

It seems happy to sit for ages in idle mode (like on the CP/M menu where all its doing is updating the clock display) but as soon as it has to do some real work it runs a high risk of hanging.

At this rate it's going to just make an interesting desk clock :rolleyes:

AccordGuy

[Sharkonwheels]

At this rate it's going to just make an interesting desk clock :rolleyes:
AccordGuy

And it will be a HUGE one, at that!

:D


Tony

[chuckcmagee]

The PX-8 is weird in that it runs off the battery, using the power adapter just to charge it up. As you can see, you have to get some initial charge going before the thing even starts acting right. Tony has the 8201a confused with the PX-8. The 8201a does have a memory protect switch on the back. As we all know, NiCads slowly discharge just sitting there unused. I fully charged a PX-8, turned off the backup battery, and put it in the closet awhile. The nicad was close to dead when I just got it out a few ago to look for mem prot sws. Yep, I'm in the "initial..." oops Charge Battery mode myself. The main battery is good until it gets to around 4.8v.

[Sharkonwheels]

No - I said MAYBE. The switch on the 8201a is for Bank2, not main RAM.

I was saying maybe, as in not remembering clearly.


Tony

[chuckcmagee]

Hey look -- a dip switch with a whole bunch of on/off switches inside my PX-8. Gollyyyy, that Tony guy was right about the switches. Now, where did I put my reference book for the PX-8. I fear it's at the bottom of a pile I can see from here.

[Terry Yager]

Hey look -- a dip switch with a whole bunch of on/off switches inside my PX-8. Gollyyyy, that Tony guy was right about the switches. Now, where did I put my reference book for the PX-8. I fear it's at the bottom of a pile I can see from here.

IIRC, most (if not all) of the switches are just for configuring for different languages.

--T

[Terry Yager]

FWIW, (I don't know if it means anything, but...) there is an internal switch that toggles in/out the charging timer (normal behavior is to stop charging after 8 hours (by the system rtc), to prevent overcharging). The switch inside the battery compartment just toggles the charging circuit to the backup battery.

--T

[AccordGuy]

Yep, the first 4 set the keyboard code page and the 5th one sets whether the PX-8 does a check for an external RAM disk. I forget what 6 does and the last two do nothing according to the manual.

There's a blue two pin jumper (empty) that is labeled "test".

Some have said that they replaced the internal battery with 4 AAA cells. What kind of battery holder fits in there? 2x2 side-by-side, 2x2 back-to-back, etc. Did NiMH cells work ok or do you have to use NiCds?

I'm thinking of using these new low self-discharge cells but the Sanyo Eneloop blurb mentions that they have a higher terminal voltage than regular NiMH cells. Is the PX-8 very sensitive to backup pack voltage? Some poor designs from that era used to use the NiCd pack as a voltage regulator (that's usually why the charger circuit can't power the machine directly, as it relies on the battery pack to limit the voltage). Certainly, the original Epson PSU is a cheap rubbishy pack with no regulation.

[Terry Yager]

In my Geneva, I replaced the internal pack with a brace of 2x side-by-side AAA holders from RatShack (I couldn't find a 2x2, but if you have one, even better). placed end-to-end, and populated with NiCads. There is room enough in there for this arrangement after the old battery has been removed.

--T

[Sharkonwheels]

If you have the means to copy the dBase ROM, I'd like one.

--T

Been a while....

Did anyone get a dump of the dBaseII ROM?


T

[Terry Yager]

I haven't.

--T

[Sharkonwheels]

T - did you see this:

linkage (http://www1.interq.or.jp/~t-takeda/hc80/index.html) ?

Win32 emulator for PX-4 and PX-8 !!!

http://www1.interq.or.jp/~t-takeda/hc80/080320-5.png

T

[Terry Yager]

Horsed around with a little a while back, but I lost track of my copy. Tnx for the refresh.

--T

[Sharkonwheels]

Now, on ANOTHER front, no promises, and it's in discussion, but I'm trying to get the creator of this amazing device (http://kenpettit.com/nadsbox.html) to make it support the Epson PX-8, as a TF-20 emulation, NOT PF-10, which will make it PX-8 and HX-20 compatible. No worries, they use same protocol, and basically same storage capacity!

If you DON'T know, it is meant as a replacement for the aging Tandy Portable Disk Drive and Drive 2. It plugs right into the serial port on the M100/M102/NEC 8201a, and is seen as a PDD, and it uses an SD card which can be written/read on a standard WinTel PC. As you can see now, TF-20 or PX-8 emu makes absolutely no difference, as I think the PF-10 was created to be a mini-version of QX-10 / TF-20 5.25" disks (40 tracks, 16 sectors, 256bytes per sector)

Cool stuff.

I am going to get a PX-8 ready for him (all batteries rebuilt, etc..) and send it to him in China to develop with. Should be super cool! Especially if it can ALL be integrated in the same firmware, with maybe a switch of some sort, or protocol autodetection!

Dude has skillz - and if you're an M100/M102/NEC buff, check out Stephen Adolph's amazing stuff, especially the ReMem at:

ReMem and Rex info (http://www.istop.com/~sadolph/remem_home.html). This is SUPER cool. It is an add-on that replaces onboard ROM+RAM, and actually creates 8 "Virtual Model 100's".

Yes, virtual. Think "VMWare" and you're close. 8 separate machines running, with their own ram+rom, each doing their own thing.

I think Rex is a huge RAM add-on for the trapdoor socket, which will hold multiples of the option ROM's.

T