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Leading Edge Model "D"

Patrick.B (TTR)

Patrick.B (TTR)

Experienced Member
Joined
May 11, 2011
Messages
496
Location
Houston, Texas, USA
So at an Estate Auction, I scored a Leading Edge Model 4, 8088 with 786K ram a 360kb floppy an MFM hard drive.
I also grabbed a leading 3edge keyboard on eBay but according to the computer there something wrong with it.
anyways it boots just fine does a memory check then aside from the "No scancode from Keyboard" error I am getting a "C80 Oh optional Rom bad Checksum = 10h" error
can not seem to find a service manual or a technical manual for this online, if anyone has one on PDF I would be appreciative to figure out what this system is doing.

Thank for any help.
NB: I put a VGA card in it for the LCD screen to work, as the two video outputs that come with it are EGA mono and colour.

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Keyboard of the wrong type (XT vs. AT) and ROM on the MFM conroller card bad. That's at least what I'd conclude from the infos posted.
 
Very nice. I've been wanting to get one of those.

There were several revisions of the "model d". What is the exact model number printed on the back?

It is a safe bet that you did not get a genuine Leading Edge keyboard - the rich keyboard kids eat those for breakfast.

On the keyboard that you did get, is there a switch labeled something like XT/AT, or 8088/286? If so make sure it is set for XT or 8088.

C800H would normally be the location for a hard drive controller ROM. First thing to do would be to check that the ROM is pushed down all the way in its socket, if it is socketed.
 
1. Keyboard, no switch, and the only markings on the underside of the keyboard is BTC-5369, which I believe is an AT keyboard. I will have to look into another keyboard of this AT2XT conversion conversation I have seen here.
2. maybe the room error is due to the VGA card I slapped in there? hard to test the theory without a proper monitor, I will have to consider mono to composite converter maybe...
 
Patrick Bureau said:
2. maybe the room error is due to the VGA card I slapped in there?
Click to expand...
No, because it uses a different address and with a bad ROM on there, you would not get a picture.

Remove the MFM controller card and see what happens. I'm sure the error will be gone then - meaning you need to replace the controller or find a dump of its ROM to burn to an EPROM.
 
Timo W. said:
No, because it uses a different address and with a bad ROM on there, you would not get a picture.
Remove the MFM controller card and see what happens. I'm sure the error will be gone then - meaning you need to replace the controller or find a dump of its ROM to burn to an EPROM.
Click to expand...

Could it be just a VGA vs MFM controller conflict? (trying to source an MDA to VGA converter to use the onboard video.)
I did find this... https://www.bonanza.com/listings/RG...pports-Commodore-128-C128-IBM-Tandy/819320890
 
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