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Unitron - Apple II clone

sid

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Joined
Feb 19, 2017
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19
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Canada
I picked up an Apple II clone system locally last week for $50 CAD (~$40 USD).

This is my first Apple II system, so I went into this knowing nothing, thought I've read a ton in the last week!

It was listed as unknown condition "as-is". It came with:
  • Zenith monochrome monitor
  • Disk II clone (Labelled "Data Drive" on case, and "Shugart" inside the drive chassis)
  • Unitron computer w/:
    • 48k RAM
    • 16k RAM expansion card (Is this the same as an Apple language card?)
    • parallel printer card
    • 80 column video card
    • floppy drive controller card

The base computer and monitor seem to work perfectly. The drive seems to function mechanically, but I don't have any Apple II formatted disks to test the drive with. I managed to get ADTPro bootstrapped using the tape ports, but I'm getting errors when using it to format disks - still working on that.

This is my first real exposure to an "Apple II" system, and I can see why this hardware had/has a loyal following. I've never seen a computer quite like this before. It's like something build by and for a hardware hobbyist... everything is labelled and socketed, and it has basically no custom ICs at all - it's like an "open source" computer - very cool!

Anyway, I took some pictures when I disassembled it for cleaning and thought you guys might find them of interest.

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KC9UDX

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Nice! I never saw that particular one before, but I've seen lots of other Apple clones, and in every case the hardware was better, sometimes much better than a real Apple.

Where was this one made? Taiwan?
 

KC9UDX

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According to Lowendmac, Germany.

It seems odd that they would go through the trouble of having a custom lower-case modification, and not use a QWERTZ keyboard with umlauts.

I think I just answered my own qvestion: I looked again at the above picture, and can see MADE IN ?????? R.O.? on the sticker on the right hand side of the motherboard.
 

snuci

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Richmond Hill, Ontario, Canada
What's interesting about yours is that it has a Multiflex Tech Inc. made card. I wonder if these computers were purchased from Unitron and resold through Multiflex Tech Inc of Markham, Ontario? I also have the Zeus 80 that is an S-100 computer with Multiflex Tech Inc ties here.

I have an Apple II clone that I think is similar but my board is green so I'll see if I can take some pics and see if they match. I remember the ROMS being in a similar configuration which I found odd. Could be sourced from a Canadian company also as mine was acquired from a fellow Canadian as well.

EDIT: If you haven't seen this page, you might want to check out the links on page. It has a picture of a blue motherboard. http://www.applelogic.org/UnitronAndI.html
 

falter

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I have pretty much the same machine. Mine was branded a Linden and has different keycaps but the rest is identical. I have been trying to buy another one because the keyboard broke while I was using it to try to restore a real Apple II.. I suspect the eprom is toast. Hopefully one day I can find a dump of it somewhere.
 

KC9UDX

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What's interesting about yours is that it has a Multiflex Tech Inc. made card. I wonder if these computers were purchased from Unitron and resold through Multiflex Tech Inc of Markham, Ontario? I also have the Zeus 80 that is an S-100 computer with Multiflex Tech Inc ties here.

I have an Apple II clone that I think is similar but my board is green so I'll see if I can take some pics and see if they match. I remember the ROMS being in a similar configuration which I found odd. Could be sourced from a Canadian company also as mine was acquired from a fellow Canadian as well.

EDIT: If you haven't seen this page, you might want to check out the links on page. It has a picture of a blue motherboard. http://www.applelogic.org/UnitronAndI.html

Anyone could have put that card in at any time. Especially if the stock 80 column / lowercase card was foreign language specific.

That site is interesting! So this may be a very good copy of an illegitimate clone!
 

KC9UDX

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I have pretty much the same machine. Mine was branded a Linden and has different keycaps but the rest is identical. I have been trying to buy another one because the keyboard broke while I was using it to try to restore a real Apple II.. I suspect the eprom is toast. Hopefully one day I can find a dump of it somewhere.

That's sad. The second best part of owning these fascinating machines is seeing what substitutes for "APPLE ][" in the ROM.
 

PgrAm

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Wow! I have the exact same machine, with the blue PCB. Same Zenith monitor too and a Shugart floppy drive though I could never get my drive to work. These must be fairly common in Canada especially in the GTA.
 

roberttx

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I think I just answered my own qvestion: I looked again at the above picture, and can see MADE IN ?????? R.O.? on the sticker on the right hand side of the motherboard.

Yep, to me it looks like it says R.O.C., ie Taiwan.

There's something else interesting about that sticker, though. The serial # is 7100013, so either they made hundreds of thousands of them or the "71" is a prefix and the OP has the 13th one made.

Edited to add: After typing that, I had a look at the Unitron page linked to above. The serial number of the board on there is 721172, so I'm not sure what to make of that.
 
Last edited:

KC9UDX

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Some serial numbers are truly serial. But in my experience this is pretty uncommon. Most are coded, and some appear to be random.
 

sid

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Nice! I never saw that particular one before, but I've seen lots of other Apple clones, and in every case the hardware was better, sometimes much better than a real Apple.

Since I got this machine, I've been keeping an eye on Ebay hoping I could upgrade to a real II+, but damn they are pricey.

So there isn't actually a quality upgrade with going to a real Apple? Any other practicle reason to upgrade to a real Apple II+ over the machine I have here?[/QUOTE]

Where was this one made? Taiwan?

Yeah, a few of the boards had a "Made in Taiwan" sticker that came off while cleaning. And as you already noticed, the mainboard was made in Taiwan.

What's interesting about yours is that it has a Multiflex Tech Inc. made card. I wonder if these computers were purchased from Unitron and resold through Multiflex Tech Inc of Markham, Ontario?

Ah, I didn't realize Multiflex was based in Markham.. interesting. I bought this one off the original owner in Brampton, so not too far from Markham.

EDIT: If you haven't seen this page, you might want to check out the links on page. It has a picture of a blue motherboard. http://www.applelogic.org/UnitronAndI.html

Wow, nice photos there. The main board looks to be the same as the one I got, though a few of the cards are different. Interesting history, thanks.

I have pretty much the same machine. Mine was branded a Linden and has different keycaps but the rest is identical. I have been trying to buy another one because the keyboard broke while I was using it to try to restore a real Apple II.. I suspect the eprom is toast. Hopefully one day I can find a dump of it somewhere.

The keyboard eprom, "Unitron K" in my photo?

That's sad. The second best part of owning these fascinating machines is seeing what substitutes for "APPLE ][" in the ROM.

Hah, I was going to ask you guys if it made sense to swap the eprom with real Apple ones. Are these clones usually 100% compatible, even with Apple brand hardware? I was thinking about getting an Apple Super Serial card for this.

(What the best part of owning these machines?)
 

sid

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Canada
Wow! I have the exact same machine, with the blue PCB. Same Zenith monitor too and a Shugart floppy drive though I could never get my drive to work. These must be fairly common in Canada especially in the GTA.

Does your drive have those bodge wires and snipped resistors on the analogue board? (See last photo, next to the bodge wires, two resistors were snipped an pulled back.) I was wondering if those were last minute bug fixes or if someone modded the drive somehow...

I got a hold of an Apple II formatted disk and did more testing: the drive boots and reads fine, but still refuses to format. If I try to format a non-Apple disk, it returns I/O error, but I try to format a disk already formatted to Apple, I get a write protect enabled error. I checked the write protect switch with a multimeter and it's fine. I read somewhere to try reseating all the ICs, but on this clone drive all the ICs are soldered in...
 

KC9UDX

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In my experience, the clones are as good as or better than a real Apple. But I haven't used them all. I don't recall any issues with software incompatibility, but again I didn't try everything on the market. Even the Laser 128 supposedly has a handful of high profile software titles that don't work.

Oh on the other hand, I do recall some issues; some poorly written programs assume that the Apple can only display characters that real ][s display. So occasionally, you'll get Chinese characters mixed in with English text. I don't recall that being a huge problem, though. The same thing can happen on real Apple hardware, with lowercase kits, or other legitimate alternative ROMs. I'm sure I've had punctuation marks where there were supposed to be uppercase characters on my upgraded ][+.
 

retrogear

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Try reseating the LS323 on your disk controller card location C3. The write protect logic is on pin 11.
Or find another chip to try. Or even another controller card. They show up cheap on ebay. I would think a standard Disk II controller would work,
just be careful to align the ribbons correctly on the pins

Larry G
 

sid

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Feb 19, 2017
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Canada
Try reseating the LS323 on your disk controller card location C3. The write protect logic is on pin 11.

I just noticed that the controller board is labelled 74LS232 at this location, but a 74LS323 is installed. Must be a typo on the board, since the link that snuci gave has a photo of a similar Unitron controller, and both the chip and the label at that location are 74LS323.

Anyway, I tried reseating the 74LS323 and no luck. However, I checked the signal on pin 11 with a logic probe and there's nothing there. Must be a bad connection somewhere, maybe the cable or something in the drive. I'll do more testing later on.

Thanks for the help.
 

retrogear

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Ok the drive has to be running. I just tested on mine.
1) Boot up drive 1 with door open so motor is on.
2) Put probe or meter on the LS323 pin 11.
3) Just slide a floppy in. It will be 0 then 4V when disk pushes switch then back to 0 when falls in notch cutout
 

sid

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Canada
The cable is definitely the problem (or at least one of the problems): I checked connectivity on each wire between the controller end and the drive end, and wire 20 is broken (no connectivity). Wire 20 carries the write protect signal, which explains why I wasn't seeing a signal on pin 11 of the 74LS323. Now that I looked closely, I can actually see the break in wire 20 right at the controller connector.

I managed to remove the IDC connector without damaging it, and cut the damaged portion off the cable. However, when I tried attaching the IDC connector again, all the pins were shorted (good thing I checked!). I removed it and tried a second time - same result. I broke the connector taking it off the third time.

I'm guessing these IDC press connectors can't be re-used? Or is there a trick to installing them?

Anyway, I'll get a couple more 20-pin IDC connectors and try again later.
 

dorkbert

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people are reading too much into the brand name of these clone machines.during the peak of cloning in Taiwan, there were thousands of small mom-and-pop shops in Taipei alone assembling these machines under their own brand names from subassemblies sourced from a dozen or so factories. A few larger companies added some interesting twists to their own motherboard layouts, but by and large most are fairly unimaginative clones.
 
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