Re: upgrading CBM-3040?

On 11/13/2017 05:53 PM, william degnan wrote:
> what would really be smooth if you could switch back and forth between 
> 3040 and 4040 modes.

Should be easy enough... Use 8K-EPROMs instead of 2532 ROMs so you can 
switch that content easily and then use, for example, a 74LS139, to 
switch between internal and external ROM for the 6530.

Will need adapters for the 3 ROMs though.

  Gerrit




> b
> 
> On Mon, Nov 13, 2017 at 11:51 AM, william degnan <billdegnan@gmail.com 
> <mailto:billdegnan@gmail.com>> wrote:
> 
>     that is my understanding.
>     b
> 
>     On Mon, Nov 13, 2017 at 11:33 AM, Francesco Messineo
>     <francesco.messineo@gmail.com <mailto:francesco.messineo@gmail.com>>
>     wrote:
> 
>         On Mon, Nov 13, 2017 at 3:17 PM, william degnan
>         <billdegnan@gmail.com <mailto:billdegnan@gmail.com>> wrote:
>         > Yes.  There was an upgrade kit.  If you can find the chips or steal them
>         > from a 4040 drive here is what I found:
>         >
>         > Replace the 6530 with the CBM chip 901466-04
>         > UL1 gets a 901468-12
>         > UJ1 gets a 901468-11  (take from 4040 UK1)
>         > UH1 gets a 901468-13
> 
>         ok, the last three chips can be 2532 EPROMs with the right
>         content, no
>         problems here.
>         Looking at the schematics, it seems that the 6530's ROM is
>         selected by
>         /RS0 only, so in theory, I could
>         make an adapter to tie /RS0 of the original 6530 high, and use the
>         select signal to enable another external EPROM for the new
>         code. The rest of the 6530 should continue to work as expected,
>         am I right?
> 
> 
>          >
>          >
>          > You'll have to convert the 2040-formatted disks to 4040
>         format to read them.
>          > The 2040/3040 will with the upgrade act like a 4040 drive.
>          >
>          > On Mon, Nov 13, 2017 at 8:20 AM, Francesco Messineo
>          > <francesco.messineo@gmail.com
>         <mailto:francesco.messineo@gmail.com>> wrote:
>          >>
>          >> Hi all,
>          >> just a quick question for the experts: Is it possible to
>         upgrade a
>          >> 3040 dual drive to DOS2.1 (like a 4040)?
>          >> Thanks
>          >>
>          >> Frank
>          >>
>          >>        Message was sent through the cbm-hackers mailing list
>          >
>          >
> 
>                 Message was sent through the cbm-hackers mailing list
> 
> 
> 


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