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mbbrutman

Associate Cat Herder
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May 3, 2003
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On everybody's favorite auction site I saw a PCjr that was untested and did not come with a power supply, keyboard, or monitor. But it did have two cartridges, an unknown sidecar, and a funny little switch hacked into the front bezel:

PCjr_jrSpeedup_PCE_memory_small.jpg


I bought it. I love funny little switches ... you never know where they lead to.

A few days later I got a pretty dirty system in the mail. But look what I found while cleaning it up:

pce_pcjr_speedup_installed_small.jpg


That my friends is a very rare PC Enterprises speedup board for the PCjr. You remove the 8088 from it's socket and plug the board into the socket. All of this fits under the diskette drive.

The board comes with a NEC V20 and some logic that allows the machine to run at 9.54Mhz. The board can insert extra wait states for RAM and ROM accesses so that the machine is stable even with the RAM being overclocked by a factor of two. It can even fill in the 16K memory hole caused by the PCjr video circuitry.

Translated into English - that's a 'Turbo Jr'. Almost 2x the speed of the original system.

I love funny little switches. The switch on this system is used to control whether the board fills in the 16KB memory hole to make the system behave more like a PC, or just leaves things as they are so that PCjr software using the better CGA+ video modes still works correctly.
 
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Sweet find! Nice eye to catch that one. I tend to get the "Wonder what that is for" when I see a non-standard switch or button.

-Matt
 
No no no no no!

Too many people cut systems up for parts. If you do the selection wrong you wind up making a mess of the parts and the system. It's almost always better to sell a complete system unless you know you have major components that are dead/bad.

Particularly on a PCjr - there are a lot of 3rd party parts that come in a set and can't be sold separately. If you sell them separately you wind up with door stops, unless somebody else has unmatched parts too. There is a seller here who did that recently to a system and it just drives me nuts, because now those single parts are floating around on eBay for outrageously high prices and they are also nearly useless.

Repeat after me .. 'We don't part systems out. We don't part systems out.'
 
mbbrutman said:
No no no no no!

Too many people cut systems up for parts.....

Repeat after me .. 'We don't part systems out. We don't part systems out.'
Click to expand...

mbbrutman,

I don't understand why you are ranting at me. I said that you could get a lot of money if you would collect all the parts needed to make this new PCjr into a complete system and then sell it. That's what I meant, anyway. I never meant to take apart one system to make this one complete. I was thinking to get the needed parts from eBay or the marketplace.

Sean
 
My bad - I misread you and thought you were suggesting to sell it for parts. You can tell that's a real sore point for me .. :-(

Somebody needs to slap me once in a while to wake me up.
 
mbbrutman said:
Repeat after me .. 'We don't part systems out. We don't part systems out.'
Click to expand...

I can understand why some sellers do this, though. A rare card in a system is likely to go for more than the system containing it. And fewer issues with trying to ship a big bulky item.

An example: I have a 386 box with 6 floppy drives driven off of two Microsolutions compaticards and a 5.25" FH SCSI drive all mounted in a large tower case. I'll guarantee you that I can get much more for the parts, tossing the case and PSU into the dumpster and selling the mobo, CCs and SCSI drive separately. Since I'd be getting rid of the item, why would I care how much of it goes toward making Toyota fenders?

Another example: Buying up C64s and extracting and selling the SID chip on eBay is likely to bring more than selling the C64 complete--and be much easier to ship.
 
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An even better example: you come across an Amiga 1200 with a 3rd party '030 or better accelerator. Since you only want it for playing games, you sell the accelerator for a good 150-200 USD to buy some games for. I don't know if that can be considered parting out a system if those were accessories to begin with.
 
I can see cases where it happens, but I see so many good systems with non-standard parts that get chopped up, and in a lot of cases the whole is worth more than the sum of the parts. If you can't use one part without the other and they get separated, that's a serious problem ..

Floppies Only - again, please excuse my misreading your. I saw the word 'parts' and a short circuit ocurred. :)

On a related note, one of the joys of finding something like this is not just the joy of having a toy, but the opportunity to learn how it works in great detail.
 
mbbrutman said:
I can see cases where it happens, but I see so many good systems with non-standard parts that get chopped up, and in a lot of cases the whole is worth more than the sum of the parts. If you can't use one part without the other and they get separated, that's a serious problem ..

Floppies Only - again, please excuse my misreading your. I saw the word 'parts' and a short circuit ocurred. :)

On a related note, one of the joys of finding something like this is not just the joy of having a toy, but the opportunity to learn how it works in great detail.
Click to expand...

It would have been stupid to take a PC/XT with a Turbo board (one of the ones that plugs into the CPU socket and where the 8088 had to be moved onto the card) apart and sell the board without moving the 8088 back to the system board. Is it events similar to this you reffer to when saying "parting out systems"?

Anyway, too bad PC/XT speedup boards are not worth that much as the PCjr ones. I only know of about 4-5 people with the same unusual 286 board I got (Computer-on-a-card architecture, doesn't plug into the CPU socket), but the last one sold on Ebay only went for about $30.

The only REALLY unusual set of hardware/software I got is someting called Aurora Vidi. I don't know of anyone else that has something like it, and it seems to be some kind of video-edition stuff. It's several 8-bit ISA cards (4 or something like that) and some early version of a wacom board with a pen.
 
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per said:
Anyway, too bad PC/XT speedup boards are not worth that much as the PCjr ones. I only know of about 4-5 people with the same unusual 286 board I got (Computer-on-a-card architecture, doesn't plug into the CPU socket), but the last one sold on Ebay only went for about $30.
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Accelerator cards for XTs were never very common and many were dumped when Windows started making inroads, as they tended to have all sorts of compatibility issues with software written for the PC AT and later.

Mostly, I tend to associate XT accelerator cards and 8-bit EMS memory cards with the people who needed to run large spreadsheets on Lotus 1-2-3.

The logic was that they were cheaper than a whole PC AT, but they were hampered by the lower performance of the XT bus and disk controller.
 
512K memory with 150NS chips.

I still need to build your Sprint circuit some day ... I have the PC boards for it but I don't know where the components are. (Grrr)


Mike
 
on the topic of parting out systems....one of my best XT clones
a Sanyo MBC-885 was parted out by an eBay seller. I bought the motherboard
and adapter cards for one dollar. Just out of curiousity I asked him what happened
to the rest of the parts, case, PS, HD, etc. He replied they were
in his garage with other stuff to be sent for scrap. Being a nice guy he retrieved
the Sanyo case , PS, HD,and other parts, and sent them to me for just the shipping
costs. I put it all back together and it works great...
So maybe some stuff that gets parted out eventually finds its way back home :)
 
dongfeng said:
Nice find!

Half the fun with getting a new machine is opening it up to see what is inside :)
Click to expand...

I agree, the best part of getting a new machine is opening it up
to discover all the adapter cards inside. Kind of spoils the fun if
the seller has already opened the system and posted pictures ...
 
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