IMC-2001

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andreas_baumann's picture
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IMC-2001

Hi there,

 

I'm on my tedious task to restore an IMC-2001 (Taiwanese Apple ][ and CP/M clone) to working order.

Some progress has been made, see https://www.andreasbaumann.cc/hardware/imc-2001/. I have a SSC now and I have one working floppy drive and can also use Fluxengine to rescue some of my disks. Most things might be either genuine Apple or CP/M stuff, or personal. The manual of the machine is here. Recommendation, wishes, etc. welcome. I'm only aware of  one other similar machine out there.

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Your motherboard appears to

Your motherboard appears to be a fairly common type with the 6502 and Z80 on the main board and the ROM chips moved to a card.  I presume there is 64K on the motherboard.

Otherwise it's a fairly standard II+ clone, although there is very little documentation.  There can be quite a bit of crossover with regards to the computer's schematic, but chip placement will likely be different in a lot of areas, so traditional troubleshooting guides are mostly useless for this motherboard, since they were designed for the genuine Apple motherboard (and 100% clones).

 

Glad you got it working, though.

 

Oh, if your Super Serial card loses characters at higher speeds make sure the IRQ DIP switch is turned on, and your communications software can use IRQs.

I recommend ASCII Express for the Apple II+. 

 

Have you got a WiFi enabled modem or some other serial-to-ethernet device that woudl allow you to connecto to BBS systems?

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baldrick wrote:Otherwise it's
baldrick wrote:
Otherwise it's a fairly standard II+ clone, although there is very little documentation.
 
 

 

This type of motherboard is mostly called GTAC-2. There are some minor differences between the variants. The board from andreas_baumann has a 24pin socket near the power connector. My GTAC-2 board does not.

 

I suppose that this socket can be populated with the F8 ROM instead of using the ROM card.

 

Regards

Ralf

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The ROM has quite some

The ROM has quite some creative layout:

- There are sockets 0-4: ROM 0 and 3 have no sockets to stick something in there. ROM 1 has 2 banks a 4k which are addressed as follows (if I stick in a 256k ROM, the original ROM 1 was broken and unbranded, so *shrug*):  0x6000 with $E000-$EFFF and from $7000 with $D000-$DFFF. ROM 2 is $F000-$FFFF. The topmost address lines of socket ROM 1 are just +5V (1). ROM4 24k is labelled on the card and is pointing down to the motherboard slot, so maybe I could replace the whole RAM card in slot 0 with a big enough ROM in ROM4. Interesting. As far as I can tell the layout of those ROMs doesn't follow any Apple standard. ROM 2 is the original one (which looks like a hacked autostart ROM with some fix in the keyboard routine to allow lower and upper case characters), ROM 1 is now a AppleSoft basic (a standard ROM, might also need some unknown patching) on a "new" EEPROM.

Thanks very much for the feedback.

Cheers

Andreas

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ADTpro runs just fine on

ADTpro runs just fine on 9600 baud (Ctrl-A 14B?), it seems. Thanks for the tipp with the IRQ, I'll try that (though the SCC manual says that there is no interrupt handling on an Apple ][ or ][+, but who knows, it's a clone, it might work). And thanks for the recomendation of communcation software.

There is 64k RAM on the motherboard. The ROM switch-off and RAM switch-on work as on a genuine Apple IIRC.

I have some old modem (56k) lying around and I could imagine to connect it to a Linux PC with ethernet using PPP, the IMC-2001 doing a dialup basically. :-)I like if things remain "epoch-true", so no VGA cards or Wifi on a breadboard with 100x the power of the original machine. :-)

Thanks

Andreas

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