RE: Who owns a 8050/8250 with tandon drives?

From: William Levak <wlevak_at_SDF.ORG>
Date: Mon, 21 Apr 2014 14:22:56 +0000 (UTC)
Message-ID: <Pine.NEB.4.64.1404211409280.11020@faeroes.freeshell.org>
On Sat, 12 Apr 2014, Hoffmann-Vetter, Martin wrote:

I have gone through the ROM images and have a number of 
questions/comments:

2040:  You have the 901466-01 image.  There is also a 901466-02.  Is it 
the same?

251474-01b:  This is the same as the DOS 2.7 Tandon. The 74LS06 hex 
inverter is probably there to provide the logic necessary to make a 4K 
EPROM appear as a 1K EPROM to the 6530.  There isn't space in the 6530's 
address space for a 4K ROM.

2.7b DOS and fdc are a version of Speeddos. The fdc has only 55 
differences with the Speeddos fdc.  The DOS has only 251 differences out 
of 16K,  99 differences if you don't count different fill byte.  The 
message area of the ROM contains the message "DOS SOFTWARE" that isn't in 
Commodore DOS.  There are also two additional commands in the command 
list, "O" and "?".

wlevak@sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org

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Received on 2014-04-21 15:01:05

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