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  • User Port Pins

    From cbmeeks@3:770/3 to All on Tuesday, September 25, 2018 10:42:35
    I'm curious about how to access certain pins of the C64 User Port. Going by the pinout here:

    https://www.c64-wiki.com/wiki/User_Port

    I see there are some pins I'm not familiar with.


    4 CNT1 Counter 1, from CIA #1
    5 SP1 Serial Port 1, from CIA #1
    6 CNT2 Counter 2, from CIA #2
    7 SP2 Serial port 2, from CIA #2
    8 /PC2 Handshaking line, from CIA #2
    9 ATN Serial attention in
    ...
    B /FLAG2 Flag 2
    ...
    M PA2 PA2


    I have a basic idea what the counters are for but I'm looking for more detailed
    information on all of those pins.

    Are there any programming and/or schematics out there that indicate how to use them in various projects?

    Thanks
    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Pekka Takala@3:770/3 to cbmeeks on Thursday, September 27, 2018 18:56:15
    On 25.09.2018 20:42, cbmeeks wrote:
    I'm curious about how to access certain pins of the C64 User Port. Going by
    the pinout here:

    https://www.c64-wiki.com/wiki/User_Port

    I see there are some pins I'm not familiar with.


    4 CNT1 Counter 1, from CIA #1
    5 SP1 Serial Port 1, from CIA #1
    6 CNT2 Counter 2, from CIA #2
    7 SP2 Serial port 2, from CIA #2
    These come from appropriate pins from appropriate CIA chips. You can use
    these for fast serial connections. The clock comes from cnt pin and data
    from sp1. Or if you input something, the chip reads from sp1 when clock
    signal comes.

    8 /PC2 Handshaking line, from CIA #2

    I do not exactly know about this.

    9 ATN Serial attention in

    I do not know why this is here. It is the same signal as in serial port.
    Could it be that CBM thought that serial ports could be used with fast
    drives?

    ...
    B /FLAG2 Flag 2

    A handshake line. This can be tied to a interrupt.
    ...
    M PA2 PA2

    You can use this pin as PB0-7. It has a DDR register and you can use it
    as input or output. Usually used as handshake line.


    I have a basic idea what the counters are for but I'm looking for more
    detailed information on all of those pins.

    Are there any programming and/or schematics out there that indicate how to
    use them in various projects?

    Thanks

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Janne Johansson@2:221/6 to Pekka Takala on Friday, September 28, 2018 15:40:40
    On 2018-09-27 17:56, Pekka Takala : cbmeeks wrote:

    9    ATN    Serial attention in

    I do not know why this is here. It is the same signal as in serial port. Could it be that CBM thought that serial ports could be used with fast drives?



    Could "Serial Attention" be the same as Ring Indication where a modem
    tells the computer to prepare for an incoming call?
    ---
    * Origin: - nntp://news.fidonet.fi - Lake Ylo - Finland - (2:221/6)
  • From Pekka Takala@3:770/3 to Janne Johansson on Friday, September 28, 2018 21:14:18
    On 28.09.2018 06:40, Janne Johansson wrote:
    On 2018-09-27 17:56, Pekka Takala : cbmeeks wrote:

    9    ATN    Serial attention in

    I do not know why this is here. It is the same signal as in serial port.
    Could it be that CBM thought that serial ports could be used with fast
    drives?



    Could "Serial Attention" be the same as Ring Indication where a modem
    tells the computer to prepare for an incoming call?

    I do not think so, because it will interfere with disk drives. Incoming
    call attention is given by rs232 lines anyway.
    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Ed Vance@1:2320/105 to cbmeeks on Friday, September 28, 2018 12:53:00
    09-25-18 10:42 cbmeeks wrote to All about User Port Pins
    Howdy! cbmeeks,

    I couldn't find my C=64 Programmers Reference Manual to help You but


    go to www.zimmers.net if You have a internet connection.

    He has all kinds of information on Commodore Products.



    @MSGID: <5BAABE2F.2792.cbm@capitolcityonline.net>
    I'm curious about how to access certain pins of the C64 User Port.
    Going by the pinout here:

    https://www.c64-wiki.com/wiki/User_Port

    I see there are some pins I'm not familiar with.


    4 CNT1.Counter 1, from CIA #1
    5.SP1.Serial Port 1, from CIA #1
    6.CNT2.Counter 2, from CIA #2
    7.SP2.Serial port 2, from CIA #2
    8./PC2.Handshaking line, from CIA #2
    9.ATN.Serial attention in
    ...
    B./FLAG2.Flag 2
    ...
    M.PA2.PA2


    I have a basic idea what the counters are for but I'm looking for more detailed information on all of those pins.

    Are there any programming and/or schematics out there that indicate how
    to use them in various projects?

    Thanks


    ... "It Shouldn't Be This Hard" - Leo Notenboom
    --- MultiMail/MS-DOS v0.49
    * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)