Re: Hardware emulation of 6509 using 6502?

From: Jim Brain <brain_at_jbrain.com>
Date: Tue, 3 Jul 2018 12:11:46 -0500
Message-ID: <3b22afea-e045-2901-9495-66ac28ff3a91@jbrain.com>
On 7/3/2018 9:37 AM, Michał Pleban wrote:
> Jim Brain wrote:
>
>> Does your exercise both $91 and $b1 opcodes?  All I can think is the
>> reads are working, but the writes are not.
> I just looked at the tests thoroughly and they use both $91 and $B1
> opcodes extensively, so I don't see any obvious reasons why the tests
> succeed but the KERNAL memory test fails.
>
> Is it possible to trace the KERNAL memory test on your logic analyzer? I
> mean the exact procedure in KERNAL which writes the value into the RAM
> and then reads it back. It would be the fastest way to see what's going
> on in the CPU.

Though I have a few different logic analyzers (8 channel, 34 channel, 
etc.), my most useful Logic Analyzer is an older HP 1650B (80 channel, 
an awesome unit, BTW, for which I did not pay much), which does not have 
a huge memory.  However, it has extensive triggering capabilities.

The easiest way to test would be to provide me with the address you want 
to start the trace at, and I will set that as a trigger.

Jim
Received on 2018-07-03 20:00:04

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