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- Newsgroups: comp.sys.cbm
- Path: sparky!uunet!mcsun!news.funet.fi!hydra!klaava!cc.helsinki.fi!msmakela
- From: msmakela@cc.helsinki.fi (Marko MΣkelΣ)
- Subject: Re: Expansion Port (or is it User Port?)
- Message-ID: <1992Dec19.232808.1@cc.helsinki.fi>
- Lines: 38
- Sender: news@klaava.Helsinki.FI (Uutis Ankka)
- Organization: University of Helsinki
- References: <92354.091124IO20197@MAINE.MAINE.EDU>
- Date: Sat, 19 Dec 1992 21:28:08 GMT
-
- In article <92354.091124IO20197@MAINE.MAINE.EDU>, IO20197@MAINE.MAINE.EDU
- writes:
- > The expansion port on the 64/128 is a parallel port, right? Does anyone know
- > how to directly control the states of the data lines on that port?
-
- The expansion port lines are connected more or less directly to the CPU. If you
- need I/O lines, use the User port or connect a I/O chip like 6821 to the
- expansion port.
-
- The Motorola 6821 could be connected as follows:
-
- Expansion port 6821
- D0-D7 D0-D7
- A0-A1 RS0-RS1
- I/O1 or I/O2 /CS2
- /RESET /RESET
- /IRQ or /NMI /IRQA or /IRQB or none or both
- +5V VCC
- +5V (via pull-up resistor)
- CS0, CS1
- GND VSS
- Phi2 E
-
- Then you'll have the 6821 signals PA0-PA7, PB0-PB7, CB1-2 and CA1-2 for the
- outside world. For programming 6821 you'll need its register manual.
-
- If you were just requesting the user port programming, I would like to
- recommend Programmer's reference guide. There are so many pins and so many
- possibilities like the fast serial transfer.
-
- Feel free to e-mail me and ask more.
-
- > assembly or BASIC. I'm bilingual.
-
- I'm tetralingual.
-
- Regards,
- Marko M"akel"a
-