Re: PLA equations for the 1551 drive's cart

Hi

For a complete paddle replacement (but with standard cartridge form factor)
there is also tcbm2sd: https://github.com/ytmytm/plus4-tcbm2sd
Arduino is optional, will disable itself if cable is attached.

28-pin triport alone has been reimplemented too
https://github.com/RetroNynjah/Fake6523-28

ytm


On Sat, Feb 22, 2025 at 1:55 PM Mario Kienspergher <contact_at_kinzi.net>
wrote:

> The soviet ones seemed very unreliably to me.
> Programming was fine, but they suddenly failed after some time.
>
> For the craddle I've developed a version with 2 x 65(C)22 and a GAL16v8.
> No need for the 82S100 or soviet clones.
>
> The 1551 was also converted into a 1551-II (using 1541-II form factor),
> using a 65(C)02 and 2 x 65(C)22 with only 3 TTLs for decoding (no GAL, no
> PLA, no need for a programmer).
>
> There even exists a drop-in converter-board to replace the 6510T and the
> 6523/6525 in an original 1551 by a 65(C)02 and 2 x 65(C)22 and only these 3
> TTLs.
>
> See Forum64 for details.
>
> https://www.forum64.de/index.php?thread/137781-gab-es-jemals-eine-1551-ii/
>
>
> https://www.forum64.de/index.php?thread/125262-1551-cpu-tia-replacement-board-wip/
>
> Regards
> kinzi
>
>
> Am 22.02.25 um 13:24 schrieb Francesco Messineo:
>
> On Sat, Feb 22, 2025 at 1:00 PM <silverdr_at_srebrnysen.com> <silverdr_at_srebrnysen.com> wrote:
>
> On 21 Feb 2025, at 09:17, Francesco Messineo <francesco.messineo_at_gmail.com> <francesco.messineo_at_gmail.com> wrote:
>
> Hi all,
> I need to program a replacement PLA for a 1551 drive, of course I have
> blank ICs.
>
> May I ask what exactly chips exactly do you have? And where can I get some? I mean if they are not the soviet ones, which I already have.
>
> of course the soviet ones, that are now unobtainable too.
> But luckily they always worked fine (except some random one that fails
> programming) and I have (I hope) a lifetime batch.
> PLS100/82S100 are almost extinct in the non-programmed state (but you
> might want to try your luck on aliexpress).
> 93459 blank PLAs are easier to find (last time I've checked) but I
> don't have any programmer that can handle them and the only known
> programmer that supports them (at least for what I know) is rare and
> expensive for those of us living in EU.
>
> HTH
> Frank IZ8DWF
>
>
>
>