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- Path: sparky!uunet!decwrl!waikato.ac.nz!comp.vuw.ac.nz!actrix!David.Empson
- Newsgroups: comp.sys.apple2
- Subject: Re: Apple SSC and CTS/RTS choking on the 6551
- Message-ID: <1992Nov22.120942.24952@actrix.gen.nz>
- From: David.Empson@bbs.actrix.gen.nz
- Date: Sun, 22 Nov 1992 12:09:42 GMT
- Sender: David.Empson@actrix.gen.nz (David Empson)
- References: <uerics.721932539@mcl> <1992Nov16.215050.13861@cs.UAlberta.CA> <1992Nov20.210357.24001@mintaka.lcs.mit.edu>
- Organization: Actrix Information Exchange
- Lines: 25
-
- In article <1992Nov20.210357.24001@mintaka.lcs.mit.edu> johnp@silver.lcs.mit.edu (John Palaima) writes:
- > Does anyone know a hardware cure for fixing the screwy 6551 on the
- > SSC card other than replacing it with the CMOS..it fixes the problem
- > but the timing ould be too far off
-
- Please elaborate. What do you mean by "the timing would be too far
- off"? The 6551 and 65C51 have nearly identical bus interface
- timings characteristics.
-
- I gather your problem with the 6551 is that CTS kills the trasmitter,
- RTS kills the transmitter, DTR kills the receiver AND the transmitter,
- and DCD kills the receiver.
-
- On the 65C51, CTS still kills the transmitter, but it lets a partial
- byte through. Similarly, DCD kills the receiver but lets a partial
- byte through.
-
- The other signals behave as before - turning off RTS will disable the
- transmitter, turning off DTR will disable all transmit and receive (and
- interrupts).
- --
- David Empson
-
- Internet: David.Empson@bbs.actrix.gen.nz EMPSON_D@kosmos.wcc.govt.nz
- Snail mail: P.O. Box 27-103, Wellington, New Zealand
-