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- SERPTCH2.PRG DOCUMENTATION April 15, 1991 by Allan Pratt, Atari Corp.
-
- All versions of Mega STe TOS and TT TOS up to 2.05/3.05 have code in the
- BIOS to communicate using the MFP and SCC serial ports. They all share a
- few problems:
-
- 1. If an SCC port's word size is set to less than 8 bits, the high bit
- of the byte you read is not correct. If you are using parity, the
- high bit is the parity bit as received. If you are not using
- parity, it's a one. It should be masked off (read as zero), as it
- is when you use the serial port on an ST.
-
- 2. If you use parity on an SCC port, and there is a parity error, the
- character will be placed in the input buffer anyway. This is not
- the same as when using the ST-compatible serial port, where
- characters with parity errors are discarded.
-
- 3. Setting the flow-control modes of some ports does not work.
-
- 4. The Iorec(0) call does not work correctly on the Mega STe.
-
- The program SERPTCH2.PRG fixes all of these problems. It is a TSR and can
- be run at any time, but is best run from the AUTO folder. Newer versions
- of Mega STe TOS (newer than 2.05), and TT TOS (newer than 3.05) have these
- fixes built in, and thus do not need the patch. The program analyzes what
- machine it is running on, what version of TOS is running, and whether it
- has already been installed, and reports what it finds. It prints
- "SERPTCH2 serial patch now installed" when it installs itself, or a message
- explaining that it is not needed and why. It uses an imperfect method
- (XBRA) to see if it has already been installed, but no harm will come if it
- is accidentally installed twice.
-
- The program ("SERPTCH2.PRG") and this document file ("SERPTCH.DOC") are
- placed in the public domain. You may copy them, give them to friends,
- upload them to bulletin boards, etc. We ask that you not modify the code
- or documentation, or that if you do, you name it something other than
- SERPTCH.
-
-