Micro II Apple clone

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I have an Apple ][ clone that I'd like to try and get running again. I have some pictures of it that I took to show what it looks like. When you turn it on, there are a bunch of vertical bars across the screen and about four rows across the bottom of the @ character. I noticed that when you turn it off and on again rapidly, a few more characters appear on the screen. I took a couple of pictures of the screen to show what I am talking about. There are 2 cards installed in the first two slots. The first slot it dedicated to the ROM card and the second slot is actually the first expansion slot which the floppy controller card is installed. When I remove the floppy controller card, the computer flicks on for a second and then turns of after I turn the power on. For some reason, it doesn't want to turn on when the card is removed. If I remove the ROM card and then turn on the computer, the computer will turn on as if nothing has changed. It is only affected when I remove the floppy controller card. I took some pictures of the two cards removed.

Thanks,

Matt
Jacksonville, FL

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gsmcten's picture
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ROM Card...

Dani,

From your last photo, it looks like two of the ROM chips have been removed from the PCB. You may not have a complete set. Considering that this motherboard does not have the slots for a complete Apple II ROM set have you thought about going to ebay and bidding on an Ineger ROM Board?

Best Regards,

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Steven (gsmcten)

"Apple ][.....It's ALIVE!!!!!"

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I figured that the card was s

I figured that the card was strictly for controlling the floppy drives as is what is printed in the upper left corner of the card. As far as a ROM board, are you referring to the other card that is listed with the two chips? If I get another expansion card and install it, do you think that the board could damage the card?
I didn't find any burned traces or burned chips.

Matt

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Yes....

The PCB with the two chips seems to be the ROM card for this computer. They may have manufactured it this way in order to keep Apple off of their back. It looks as though two of the chips have been removed. I cannot see anything wrong with your drive card.
Like I said; you may want to check out eBay for an Integer ROM card since yours is incomplete. Smile

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Steven (gsmcten)

"Apple ][.....It's ALIVE!!!!!"

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I need some schooling on this

I need some schooling on this as I am a PC guy, I am piddling with this because it's got my interest and it's different.

1. You say that My Integer ROM card isn't complete. Are you referring to the floppy controller card?
2. Is the floppy controller card also a ROM card?
You've got me confused because the only card I know of that is a ROM card is the one with 2 chips.
3. Could the system board burn out an expansion card if the board is bad?
4. Would the 2 chips that are missing cause the display to do like it is doing?
I noticed a chip on the board that has a broken pin on it. The number on the IC is SN74LS259N with a row of numbers above it J349A and it has a Texas Instruments logo with a total of 16 pins. I may be able to fix it by soldering another pin to it.

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Ok...

Let me see if I can explain it better.

The ROM "Card" and the Floppy Controller "Card".
You pulled both of these from the motherboard, right?

The Floppy Contoller card does not contain ROMs.
The ROM card that you took a picture of looks like it is missing two chips. It seems to me from the photo that they have been de-soldered.

A NORMAL Apple II Plus motherboard has the ROM chips installed just above the RAM chips. Anywhere from four to six of them.

You really need pictures of a normal Apple II to see the differences.

Now, the chip that you say has a broken pin may also be part of the problem. You can pick up 74LS chips from Jameco Electronics. They carry these ready for shipment at a reasonable price.

I hope this helps a little. Smile

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Steven (gsmcten)

"Apple ][.....It's ALIVE!!!!!"

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Thanks for the info. As for t

Thanks for the info. As for the ROM card, it appears that it never has had but two chips that are already on it. There is solder in place in case you were to add additional chips or sockets but it doesn't appear that the solder has ever been used. I also noticed that every chip on both the main board and expansion cards are socketed. I have a few more questions for ya.

I mentioned earlier that when I remove the ROM card, nothing changes. When I remove the floppy controller, the computer will not power on.
1. Due you know what could cause this? Is there more to the floppy controller then meets the eye? Also, I'm afraid that I might fry a chip for some reason even though I don't see any burns anywhere.
2. Is there a way that you can test for a short in the circuitry to avoid burning a good chip? Just trying to be cautious.

Matt

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On the Disk Controller Card...

It looks as though there is a missing 74LS174 Chip.
That Card also looks like it has seen better days.

I cannot asnswer your other question as I have never seen an Apple ][ motherboard quite like this one. I think you need to ask one of the gurus about this. I am but a modest II enthusiast. Smile

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Steven (gsmcten)

"Apple ][.....It's ALIVE!!!!!"

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I found a site that had a ser

I found a site that had a service manual for an Apple II and I printed out the part that tells where each chip is supposed to be by using a grid type of setup that reminds me of Battle Ship. I used this to compare the chip configuration of my board with the Apple II board as my board has a grid layout just like the Apple with an alphabet layout starting with A at the lower left corner of the board running up the side to J and numbers running from lower left to right starting with the number 1. So far, my board appears to be about 65% exact to the Apple II board. You said that this is best left up to one of the expert Gurus, how do I get in touch with them? As of right now, I'm at the mercy of whoever reads this thread.

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Try posting to comp.sys.apple

Try posting to comp.sys.apple2

or contact Mike Willegal.

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Re: Micro II Apple clone

Update... I posted on comp.sys.apple2 and got in touch with Geoff Body in Australia who walked me through various tests and replacing of various chips. He ended up ordering some items from Ebay and had them shipped to me to verify the contents and then had me pack my motherboard, controller card, and ROM card and ship it to him. it took about a year but he fixed it and shipped it back to me and wanted nothing for it in return. A really nice guy and rare. So it is up and running now. He sent me 3 floppies to use with it. C/PM, DOS 3.3, and ProDOS. The only disk that will work is C/PM. The first time I tried to boot from ProDos it said : "?Syntax error in 130 when in slot 7".
I moved the controller card to slot 6 and then after powering it back up I got the following, "#1940" and the disk kept spinning until I powered it back off. I tried Dos 3.3 but when I powered it on the disk kept spinning but no response. Any ideas on what the problem is and what #1940 means in ProDOS?

Matt

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Re: Micro II Apple clone

Quote:

The only disk that will work is C/PM.

Probably you need to switch to the 6502 CPU.

There is a Bulgarian clone (Pavetz 8M) with build in Z80, similar to this one. It has a set of microswitches to select the mode Apple / CP/M. However I don't see microswitches or jumpers here, so it must be done some other way.

This clone - http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Computers/Other/Boss-1/Manuals/
is using ROM card and there is a menu t select.
Do you have the ROM card installed in the first slot?

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Re: Micro II Apple clone

I have it in the slot marked ROM. It is just before the 1st expansion slot.

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Re: Micro II Apple clone

Hi,
Do you know what Geoff replaced to fix your system?
I noticed that pin 41 in the Z80 IC was not in the socket
In the pictures you had originally posted.
Sincerely,

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Kelvin

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Re: Micro II Apple clone

I meant to write pin 21 of the Z80A which is the RD signal.
Your Disk II Interface definitely needs the 74LS174 and the
9334 to operate correctly. I have the same MB with ROM card.

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Kelvin

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Re: Micro II Apple clone

Hello dani9678,

lets first start with the simple part - the diskcontroller:
It must be completed by a 74LS174 at position A3 and
the 9334 at position C2 must be completed by eiither a DM9334 or the replacement DM74LS259 !
That card shall be placed in the slot no. 6 which is the second slot beginning the count at
the video output plug. One note to this card: The electrolytic capacitor C2 looks rather aged
and it is recommended to "recap" ( replace ) that 22µF /16 Volt electrolytic capacitor and
when replacing it take care of the marking of polarity + and - !

The ROM card must be plugged in the ROM-Slot.

And of course the Z80 CPU at position F7 must be inserted correct -
meaning that pin 21 must be IN the socket and not besides....

After that corrections try boot up again and report back....

This kind of mainboard with integrated CPM card "on board" at the mainboard was rather common....

You should recognize that in most cases the mainboard was able to detect by bootup of a disk
if the disk contained normal DOS or CPM and then automatically switched to the demanded CPU
( either 6502 or Z80 ).

Bear in mind that most of this mainboards have not been able to bootup ProDOS -
at least not without patched ProDOS !

sincerely
speedyG

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Re: Micro II Apple clone

I don't believe that the ROM card is incomplete because,

1) there isn't any solder seen on top of the card, which will be the case when parts are soldered previously
2) here's a link showing a clone ROM card which looks exactly the same...
http://www.ebay.de/itm/ROM-card-for-the-Apple-II-clone-the-BOSS-II-1-3-/201607966831?hash=item2ef0c5706f:g:8~4AAOSwGIRXaGcj
3) while this one has 3 chips installed
http://www.ebay.de/itm/ROM-card-for-the-Apple-II-clone-the-BOSS-II-2-3-/201607953014?hash=item2ef0c53a76:g:ZY8AAOSwzJ5XaGAJ

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speedyG's picture
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Re: Micro II Apple clone

The version with 3 x 2732 Eproms was normal in early boards while in later boards
the "mixed" version was common 1x2764 with Basic and 1x2732 with bootcode.
speedyG

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the second part includes less friends but a lot more joy on life....

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Re: Micro II Apple clone

He replaced both ROM chips on the ROM card, repaired the floppy controller so that it would work again. He said that all up he replaced 4 sockets and twenty nine 7400 series IC's.

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Re: Micro II Apple clone

I don't bother on what somebody says....
if he states the floppycontroller to be in working condition that's definitly wrong statement !
That Floppycontroller won't get to operating status with that 2 chips missing !
And if such statement has been given - it's serious indication to doubt in the other statements....
I'm beyond that age to believe in fairytales or "easter bunnies"
- exept those bunnies displayed at Playboy...
LOL

sincerely
speedyG

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In early days I had a lot of money but no time - now I have no money but a lot of time....
the second part includes less friends but a lot more joy on life....

ggb
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Re: Micro II Apple clone

Hi Speedy,
it's sad when I see that it appears that you have been doing what you complain that other people do, by not reading/following the thread.
This thread was started in 2009 which is when the pictures were posted and they have not been changed.
The clone board and controller were repaired and returned in late 2012.
MSG#10 states that it would boot CPM, just not the PRODOS and DOS.
To boot CPM the disk controller needs to be working ( for INFO the disks were old media).
This thread was picked up again in 2016 three and half years after posts from 2013
At this point you have decided to participate in this old thread and indicate that I have given doubtful statements.

QUOTED
I don't bother on what somebody says....
if he states the floppycontroller to be in working condition that's definitly wrong statement !
--- how can you say that based on pictures from 2009
That Floppycontroller won't get to operating status with that 2 chips missing !
--- as of late 2012 it wasn't missing any chips and was working.
And if such statement has been given - it's serious indication to doubt in the other statements....
--- clearly your comments based on 7 year old pictures indicate that I must be giving misleading information, but I have not.
I'm beyond that age to believe in fairytales or "easter bunnies"
- exept those bunnies displayed at Playboy...

Regards
GeoffB

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Re: Micro II Apple clone

Is that you Geoff? If so then wow it has been awhile hasn't it? Nice to see you again (Figuratively of course). I got one of your emails back at Christmas. I responded but you were probably busy. As you can see the MICRO II is still operational. I have been wanting to do some upgrades but it hasn't been a priority and on the back burner. I still have that issue with the CAPSLOCK switch but I figured maybe another keyboard might fix it.

Matt

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Re: Micro II Apple clone

Hello ggb !
Yes i do apologize !
i did read the entire thread ....
- but i did not pay also attention to the dates of the postings !
So i really missed that skip of 4 years between posting #9
and posting # 10 .....

and yes: the thread was then off topic for another 2 1/2 years again
and AppleEmp393 also again mentioned the mistakes at the pictures from posting #1 !

But also i must reject one accuse:
the pictures in posting #1 still display the controller without the chips and
the mainboard with the dislocated Z80 CPU !
And that pictures haven't been updated.....

And my final note to ProDOS is still valid:
Within ProDOS there is code to check for the
routine if really "Apple ][" is displayed on Top
of the screen and most of that mainboards don't
display that comtutertype as "Name" and then
unpatched ProDOS will abort further bootup !

sincerely
speedyG

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In early days I had a lot of money but no time - now I have no money but a lot of time....
the second part includes less friends but a lot more joy on life....

ggb
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Re: Micro II Apple clone

Hi Speedy,
thank you for your apology.
As for ProDOS loading, I had to replace the EPROMs due to both being faulty and not having any suitable images for the system I used the Apple II ROM images to create the new EPROMs.

Regards
GeoffB

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Re: Micro II Apple clone

Hi,
Does anyone have any clear pictures of the IC's and or documentation on the motherboard since I believe that the silkscreen labels are under he sockets?
I have one I am trying to restore which will not reset and think it maybe the two ROM's or maybe the edge connecter socket itself that is oxidized.
Thanks in advance,

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Kelvin

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Re: Micro II Apple clone

Hi Kelvin,

I'm trying to do exactly the same thing to no avail.
Here are the pictures of my motherboard (use Download in the Actions menu to get the hires files).
Don't hesitate to ask if you can't read one reference.
If you find mismatches, I will be glad to hear from you !

HTH,

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Antony
Apple II forever

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Re: Micro II Apple clone

Hi Anthony,
That appears to be another variant of the motherboard.
It is very similar except that yours has a DIP socket to the left of the slots.
I believe that it's used in place of the ROM card slot.
If you were able to install a known good ROM containing the right code
Your system might work.
I suspect that my ROM card may be bad or the card slot connectors may be
too tarnished for a good connection.
My motherboard looks exactly like Matts'.
Thanks for uploading the pictures.

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Kelvin

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Re: Micro II Apple clone

Kelvin,

I've tried with a ROM card. No luck so far.

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Antony
Apple II forever

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Re: Micro II Apple clone

Hi Anthony,
Did your ROM card have two or three chips?
I have the two chip variety.
The EPROM on the left is a 2764 and the right one is a 2732.

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Kelvin

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Re: Micro II Apple clone

Kelvin,

I have this one.
It appears to be the same as yours with a 2764 and a 2732.

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Antony
Apple II forever

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Re: Micro II Apple clone

Antony,

I have the similar ROM card without the resistor SIP at the bottom near the edge connector otherwise mine is the same.

I dumped and saved the two ROM's so they could be read and the first few lines of code seem to be OK but I did not trace thru it all of the way,

I am think of blowing two new ROM's with the code for a backup.

If the current ROM's are good the tarnish on the slot socket is still questionable.

It might be time to drag out an O'scope as well even through the output on the display would suggest a problem with the ROM's.

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Kelvin

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Re: Micro II Apple clone

Hi Antony,
I made an MS Excel file containing the IC layout from the pictures of your motherboard.
There were two IC's that were different -
Replaced D1 (Originally had a 74LS05) with 74LS04 per your MB.
Replaced D6 (Originally had a 74LS40) with 74LS20 per your MB.
I switched them out to match your motherboard but it did not help.

If you or anyone else would like a copy of the of the file PM me.

BTW, using my logic probe on the keyboard socket Reset pin the RESET line is being held low.
It should normally be high then go low when the Reset key is pressed.

The collector pin of the transistor around A13 was holding the RESET line low.

I clipped it and can now do a manual reset as well as cold boot the system into DOS.

BTW, it displays APCOM II after the initial reset or while booting into DOS.
SO...It could be a Sunrise Apollo APCOM or a Jardine APCOM Personal Computer MB.

The code in the two ROM's appears to be OK as well.

The only remaining hardware issue is that it does not display data typed in on the keyboard.

I have checked the usual suspects but they were OK.

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Kelvin