Re: Modern, but fully compatible 6502?

From: silverdr_at_srebrnysen.com
Date: Mon, 5 Sep 2022 08:01:08 +0000
Message-Id: <75C8291D-E47D-4FA3-8B14-089EDC62DD91_at_srebrnysen.com>
> On 2022-09-04, at 19:41, Gerrit Heitsch <gerrit_at_laosinh.s.bawue.de> wrote:
> 
>>>>>> ... but other than that?
>>>>> 
>>>>> Unless you are talking about a 14 MHz version.
>>>> No, I don't need higher clock frequencies
>>>>> what's wrong with the original one then?
>>>> 1) they aren't officially available[*] so one has to count on some rather dubious sources, which sell "NOS"[**] ones, and 2) its DIP "footprint" is imposing limits I'm not too happy with
>>>> * - unless I am missing a reliable source with some stock and reasonable prices
>>> 
>>> Have you tried https://www.unicornelectronics.com/index.htm
>> No, I haven't yet.
>>> They list the NMOS-6502 at OK prices under
>>> 
>>> https://www.unicornelectronics.com/IC/6500.html
>> Prices look OK for one or a few. Not so much for a production batch. I am not sure if BOM for a PLD capable of implementing it wouldn't be less expensive.
> 
> Possibly... But would that also cover the illegal Opcodes correctly? From what I understand, those are side effects of the NMOS implementation.

Since I remember reading some time ago that all the undocumented opcodes with their respective behaviour were analysed and understood, I assume (maybe wrongly?) that they've already been implemented. I take at least some projects need that full, low level compatibility. Gideon's come to mind first but also the mentioned Visual6502 spinoff might be very interesting.
Received on 2022-09-05 11:00:06

Archive generated by hypermail 2.3.0.