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Unitron - Apple II clone

Well, I figured out why the re-attached IDC connector was shorted: the ribbon cable actually has second layer of plastic laminated on covering a copper mesh - some sort of shielding I guess, never seen that before. Anyway, after peeling off a bit of the mesh and plastic, I got the IDC connector on without any more problems, and the drive is now working 100%.
 
I've seen that before on genuine Apple Disk ][s, presumably from right around the time original ][s and ][+s came with makeshift shielding.
 
If its not using a mask programmed microcontroller then the eprom will be the same as the other clones of the day, I probably have one here that is the same.
Post a photo of your keyboard and I'll upload a suitable eprom image.

falter said:
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.
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sid said:
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.

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?)
Click to expand...

You may want to reprogram the f8/f0 eprom so it displays "APPLE ][" unpatched version of prodos won't boot unless it says apple on the screen. Other than that the ROMS are identical.
 
Good thing nothing for the C64 does that. I mean, the first thing one does when burning a custom KERNAL is change the READY. prompt. The second thing is the boot screen.
 
David_M said:
You may want to reprogram the f8/f0 eprom so it displays "APPLE ][" unpatched version of prodos won't boot unless it says apple on the screen. Other than that the ROMS are identical.
Click to expand...

Ah, good to know. I guess I'll have to pick up a programmer one of these days.

KC9UDX said:
Good thing nothing for the C64 does that. I mean, the first thing one does when burning a custom KERNAL is change the READY. prompt. The second thing is the boot screen.
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Probably never a reason to - were any C64 clones ever made?
 
I wonder how ProDOS could do that. Different official ROMs say different things:

APPLE ][
APPLE ][+
Apple //

Are just three of the ones I have. I don't recall what the //c says, maybe Apple //c, and my GS doesn't boot anymore; maybe it says Apple ||?

Maybe it searches for any of those, or just Apple, in either case? I wonder how early versions would detect later ROMs.
 
I am not aware of any version of ProDOS checking for the string "Apple". Even early versions determine model by looking at some id bytes at $FB1E, $FBB3 and $FBC0. There should be an RTS at $FE1F.

Larry G
 
Back in the day when Prodos first came out I worked for a company selling apple clones, the only difference was the name string in the F8 ROM. Prodos would not boot past the title screen, simply changing those 8 bytes back to APPLE ][ solved the problem.
As far as I know it does a case insensitive check for the word "APPLE". You can easily test it yourself, from memory in an Apple 2+ the name is stored at FB09h with bit 7 set on all characters.

Edit: I found this on wikipedia, it confirms my recollection.
https://en.wikipedia.org/wiki/Apple_ProDOS

retrogear said:
I am not aware of any version of ProDOS checking for the string "Apple". Even early versions determine model by looking at some id bytes at $FB1E, $FBB3 and $FBC0. There should be an RTS at $FE1F.

Larry G
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If it were me, I'd rather hack ProDOS. Having a nonstandard boot logo was always appealing.
 
I can understand that appeal. Two of the clones I acquired late last year were originally imported by the company I worked for in the early 80's.
One had indications that I had actually done a repair on it personally. So I have decided to keep the non standard boot name in those machines for nostalgia sake.

Of course the apple 2e I picked up last week now makes that decision easier since I will have something to boot unpatched prodos when needed.

KC9UDX said:
If it were me, I'd rather hack ProDOS. Having a nonstandard boot logo was always appealing.
Click to expand...
 
David_M said:
I can understand that appeal. Two of the clones I acquired late last year were originally imported by the company I worked for in the early 80's.
One had indications that I had actually done a repair on it personally. So I have decided to keep the non standard boot name in those machines for nostalgia sake.

Of course the apple 2e I picked up last week now makes that decision easier since I will have something to boot unpatched prodos when needed.
Click to expand...

That's remarkable, reconnecting with a machine after presumably a rather long time. I've been searching (in Australia for the most part) for a Datamini Apple clone for some time now, but in the past 2 years have picked up 4 others instead from Redstone (sold now though), Maple, Elite and an unknown one that comes up as "VectorIO". Are any of those connected to your former employer?
 
No none were sold by the company (Computer Edge) that I worked for. We were the company that fought the landmark copyright case against Apple, we won the first case, they appealed and won then we won the high court appeal. Not long after that the government lobbied by Apple amended the copyright laws to include computer software.

I got an even bigger surprise than just finding a "Wombat" that I'd worked on. The guy I got it from turned out to be an old client from my after hours business repairing computers. He has collected apples and clones for 30 years and has sheds full of them. He brought over about about 6 complete machines, a few monitors, 20 motherboards, and power supplies for me to repair along with a coup[le of hundred apple cards. One of the cards, an eprom programmer had been modified with a switch to support 27128's. That switch was one used in a trs-80 clone (komtech) we used to sell so I knew it could only have come from where I worked. Imagine my surprise when I turned it over and there was a sticker with my name on it. Turns out it was my own personal eprom programmer from 30 years ago that I'd sold and forgotten about years ago.
He gave me that card as a gift.

This is the card in the condition I got it back in.
14581447_1290427247654431_4044330996632426482_n.jpg

I've since cleaned it up and got it working although I've not actually tried to program and eprom with it, reading eproms works fine.

Freestyle said:
That's remarkable, reconnecting with a machine after presumably a rather long time. I've been searching (in Australia for the most part) for a Datamini Apple clone for some time now, but in the past 2 years have picked up 4 others instead from Redstone (sold now though), Maple, Elite and an unknown one that comes up as "VectorIO". Are any of those connected to your former employer?
Click to expand...
 
Hello, I just registered. First post with a funny story. My son (Nigel) got me an Apple II clone for Christmas. I had one in high school (a LONG time ago). I ended up throwing it out years ago (with all of the software I had written for school projects etc). Just no room to store it. I've been reading up on the II recently thinking I might get back into it.

Guess what. It's this machine. Same serial number. Same little dots on the disk drive top. Came with a commodore colour monitor though.
I was looking for info on the 80 column card and under images that card showed up and sent me to this forum.

My first clone was a solder together yourself, mount to a piece of plywood, build your own power supply and used a sony cassette for data storage. Couldn't afford a case or hard drive. Once the IBM clones started coming out, the case, disk drives etc dropped enough in price that I could afford them.

Small world.





sid said:
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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