Re: Theorizing: cloning CBM electronics with modern technology.

On 3/22/22 17:47, ruud_at_Baltissen.org wrote:
> Hallo Claudio,
> 
> 
>> Recently, clones of the 1581 electronics have surfaced, and I wondered
>> about how much of the electronics can be put on FPGA/CPLD and what not.
> 
> Just have a look at the Ultimate1541 and you have your answer: the
> sky is the limit.
> Personally I prefer projects without PLDs and/or FPGAs for various
> reasons:
> - most of the times it means SMD soldering and pins very very close
> to eachother
> - not everybody can program them and most probably the need socket
> converters
> - most of the newer CPLDs/FPGAs are non 5 Volt meaning voltage
> shifters are needed, thus extra parts, etc., etc., etc.
> 
> 
>> Can the standard PCB of a 1541 be replaced by a newer, designed from
>> scratch one, while maintaining hardware compatibility, when managing the
>> drive mechanism?
> 
> Just two words: why not? Have a look what is needed to turn a 1541
> into a much better machine:
>     http://vic-20.de/x1541/hardware/petram.html
> What about adding 1 MB of SRAM and a SD interface? Load the RAM with
> the content of a floppy and loading a 200 block from RAM is a matter
> of seconds. (Sorry, I forgot the board that did that already in the
> '80s)
> Board size? when using a 1541, thus not the 1541-II, you have room
> enough for the extra goodies.

And if you want to build the 1541 without any custom chips, take a look 
at the old 1541 with the longboard or the Oceanic OC-168. That gets you 
the basics, then just add whatever you need.

And there is already a project where the drive mechanism was replaced 
with an SD interface in a way that any code that will run on a real 1541 
(fastloader an such) will also run with it.

  Gerrit