Re: Still struggling with a 6551 (rockwell)

From: didier_at_aida.org
Date: Fri, 27 Oct 2023 16:41:48 +0200
Message-ID: <a10017a3-40bf-4900-a2e7-c3c0a21fda90_at_aida.org>
no success with the 6551 even with CTS grounded
In coninit I  changed LDA #$CA
for LDA #$0B   1 stop bit, 8bits, internal baud rate, 9600 bauds
1.8432 Mhz is on XTAL1
there is a signal on CS1 showing the rom code is running and accessing 
the ACIA

after the initialisation the code running is:
LOOP   LDA #$24
             JSR CONOUT
            JMP LOOP

same result with a w65c51 running with david gray  hack to replace the 
check of TDRE
a signal is received on pin RXD
no signal out of the TXD pin on the 6551 or w65c51



On 27/10/2023 14:51, Gerrit Heitsch wrote:
> On 10/27/23 14:45, didier_at_aida.org wrote:
>> I'm still struggling with the Rockwell 6551
>>
>> I probably did something wrong but I can's see what
>>
>> RX / TX are connected
>>
>> CTS/RTS are not connected
>
> The CTS pin needs to be grounded when not used. See schematics for the 
> Plus/4.
>
>  Gerrit
>
>
>
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>
Received on 2023-10-27 17:00:08

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