Re: upgrading CBM-3040?

From: Francesco Messineo <*francesco.messineo_at_gmail.com*> Date: Mon, 13 Nov 2017 17:59:07 +0100 Message-ID: <CAESs-_yFAW+jXAp1rxw4q0i2003Naa571gv9VoD=nfuXFuDmcQ@mail.gmail.com> · francesco.messineo_at_gmail.com

On Mon, Nov 13, 2017 at 5:53 PM, william degnan <billdegnan@gmail.com> wrote:
> what would really be smooth if you could switch back and forth between 3040
> and 4040 modes.

I can do that, I've designed 2332/2364 compatible replacements using
28C64 EEPROMs, so
with a little PCB change, I can put two images on each 2332
replacement and use a common address
to select "upper" or "lower" images.
The 6530 Internal/External ROM change could be selected with the same
signal, by adding some simple logic.
I think I would need an external switch to select the ROMs anyway.

> b
>
> On Mon, Nov 13, 2017 at 11:51 AM, william degnan <billdegnan@gmail.com>
> wrote:
>>
>> that is my understanding.
>> b
>>
>> On Mon, Nov 13, 2017 at 11:33 AM, Francesco Messineo
>> <francesco.messineo@gmail.com> wrote:
>>>
>>> On Mon, Nov 13, 2017 at 3:17 PM, william degnan <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> 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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