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| | How to build a RS232 - Interface for the CPC-Series! | | How to build a RS232 - Interface for the CPC-Series! |
| − | [[http://www.cpcwiki.eu/index.php/File:Rs232cpc.lzh]] ==================================================== | + | [[link to file http://www.cpcwiki.eu/index.php/File:Rs232cpc.lzh]] ==================================================== |
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| − | Okay, you have received the plan, how to construct a RS232 Interface for the
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| − | CPC. I hope you can read the numbers in the GIF-File. This README-File includes
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| − | more details about the RS232-Interface, how to connect the adress-bus with
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| − | the Interface and RS232.ASM contains an assembler routine to use the Interface
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| − | under BASIC.
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| − | I think, the best way to build the interface is to print the GIF file and
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| − | connect the components with each other.
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| − | First about the connection plan: You need a power supply that supports +9V,
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| − | -9V and 5V. Connect all pins. You have to
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| − | connect D0..D7 from the adressbus with the
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| − | Z80 STI. You have to connect D0 with pin 21,
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| − | D1 with pin 22, ..., D7 with pin 28. That's
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| − | all. Now you can plug in the interface in the
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| − | CPC. Switch the power on. If the CPC doesn't
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| − | work normal please switch the power off and
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| − | you have to watch for faults in the connection
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| − | of your interface :-(. If everything is ok then
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| − | you have to copy the assembler code and do the
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| − | next test.
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| − | WARRANTY: There is no warranty of any defects of your CPC!!! On my CPC every-
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| − | ========= thing works fine and I hope that you won't have any problems with
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| − | this RS232-Interface.
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| − | Second part: How to program the interface. (The assembler code is saved in
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| − | ============ RS232.ASM)
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| − | Z80-STI: 50 to 19200 bps (5,6,7 or 8 bit, 1, 1 1/2, 2 stopb., all parity flags)
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| − | 24 registers,
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| − | use 16 registers (direct) with F8E0-F8EF,
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| − | the last 8 registers can be used indirect with a special register
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| − | The meaning and the adresses of the registers:
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| − | register 0, port adress F8E0:
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| − | This register transfers data from and to a indirect register.
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| − | register 1, port adress F8E1:
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| − | This register transfer the data from and to the I/O port of the chip. If you
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| − | use V24 you can request handshake signals from this port. In this interface
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| − | the following bits have this meaning:
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| − | Bit 0: DTR (Data Terminal Ready)
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| − | Bit 1: RTS (Ready to Send)
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| − | Bit 2: CTS (Clear to Send)
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| − | Bit 3: DSR (Data Set Ready)
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| − | Bit 4-7: not used
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| − | register 2-7, port adress F8E2-F8E7:
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| − | These registers are used by the interrupt handler. If you want to know
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| − | what you can do with this registers please write to Mostek for support.
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| − | register 8, port F8E8:
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| − | Bit 3-7 are used by the interrupt handler. With bit 0-2 you can choose the
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| − | indirect register.
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| − | register 9, port adress F8E9:
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| − | Controll register for timer A and B. You needn't to use the timer for a V24
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| − | interface.
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| − | register 10, port adress F8EA:
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| − | Timer B value
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| − | register 11, port adress F8EB:
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| − | Timer A value
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| − | register 12, port adress F8EC:
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| − | USART-register. Change the connect-parameters.
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| − | Bit 7 6 5 4 3 2 1 0
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| − | x x x x x x x 0
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| − | ^ ^ ^ ^ ^ ^ ^
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| − | | | | | | | 1=even
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| − | | | | | | | 0=odd
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| − | | | | | | 1=Parity on
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| − | | | | | | 0=Parity off
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| − | | | | Startbit Stopbit Format
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| − | | | | 0 0 = 0 0 synchron
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| − | | | | 0 1 = 1 1 asynchron
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| − | | | | 1 0 = 1 1 1/2 asynchron
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| − | | | | 1 1 = 1 2 asynchron
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| − | | 0 0 = 8 Bit
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| − | | 0 1 = 7 Bit
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| − | | 1 0 = 6 Bit
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| − | | 1 1 = 5 Bit
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| − | please always set on 0
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| − | register 13, port adress F8ED:
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| − | Receiver status. You need only the following bits:
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| − | Bit 0: Receiver-Enable, set to 1 if receiving is possible.
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| − | Bit 1: Memory full "1" or not "0". (If 8 Bits are received then the interface
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| − | send memory full).
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| − | register 14, port adress F8EE:
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| − | Sending status. Again you need only two bits:
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| − | Bit 0: Sending-Enable, must set to "1" if sending is allowed.
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| − | Bit 7: Memory full "1" or not "0". This bit can be used to ask if a word is
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| − | send or not.
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| − | register 15, port adress F8EF:
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| − | This is the send and receive register. Here you can get a word or send a word.
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| − | Indirect registers (Choose them with register 8):
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| − | =================================================
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| − | register 0: Not used.
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| − | register 1: Data for Timer D.
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| − | register 2: Data for Timer C.
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| − | register 3: Not used.
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| − | register 4: Not used.
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| − | register 5: Not used.
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| − | register 6: I/O-Port (receive or send). High means sending, low receiving.
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| − | register 7: Used for Timer C and D. Reset with "1".
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| − | For more exact informations please write to Mostek and ask for support for the
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| − | Z80-STI. You also can look at the assembler code.
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| − | About the assambler code:
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| − | =========================
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| − | The program RS232.ASM installs 2 new BASIC commands (|FORMAT, |RECORD, |SEND).
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| − | Here you can read the description about this new commands:
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| − | |FORMAT, number of bps, number of stop-bits, data bits, parity on/off, parity
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| − | even/odd
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| − | Number of bps: 0 = 50 bps
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| − | 1 = 75 bps
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| − | 2 = 110 bps
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| − | 3 = 150 bps
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| − | 4 = 300 bps
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| − | 5 = 600 bps
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| − | 6 = 1200 bps
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| − | 7 = 2400 bps
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| − | Number of stop bits: 1 = 1 stop bit
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| − | 0 = 2 stop bit
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| − | Data bits: 0 = 7 data bits
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| − | 1 = 8 data bits
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| − | Parity: 1 = even
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| − | 0 = odd
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| − | Parity: 1 = on
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| − | 0 = off
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| − | Normally, you use 8N1 for connection with BBS's you can initialise this with
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| − | |FORMAT, number of bps, 1, 1, 0, 1.
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| − | |RECORD, @a$
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| − | The incoming chars will be read in a string. Control codes will be send to the
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| − | string, too, because sometimes you need it for binary transmissions.
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| − | |SEND, @a$
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| − | The string is send until it ends, except you press ESC. The program will not
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| − | send CR or LF, so you can use this for binary transmission.
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| − | Last words:
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| − | ===========
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| − | This interface is described in the book "Maschinenspracheprogramm und Hardware-
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| − | erweiterungen fuer Schneider CPC's" from the IDEA Verlag. I hope that every-
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| − | thing is ok with the circuit plans and that you don't have a broken CPC when
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| − | you use it ;-).
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| − | Sorry for bad english. (Please help me to find my faults).
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| − | If something in my circuit plan is not ok please write to
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| − | Tim Riemann
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| − | Gartenweg 3
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| − | 35114 Haina-Kloster
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| − | Germany
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| − | eMail: TCS-Software@t-online.de
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| − | Third part: Used components:
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| − | ===========
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| − | 1 Z80-STI (or MK 3801-4)
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| − | 1 SN 75189
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| − | 1 SN 75188
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| − | 1 74 LS 30
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| − | 1 74 LS 138
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| − | 1 74 LS 20
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| − | 1 74 LS 04
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| − | 1 74 LS 32
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| − | 1 25pin SUB-D connector (male)
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| − | 1 connector for the expansion port
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| − | That's all!
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| − | [[Link title]]
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