YOUNG@dec-marlboro.ARPA (04/29/86)
I have an old XEROX 820-II which I am using for packet radio purposes. Right now I am using it as a dumb terminal, running SMARTERM, but I would like to make it more clever. To do this, I have to know how to program the I/O port, and possibly how to handle interrupts from the keyboard. I would like to use DTR/DTS on the serial port. I'd prefer to do it in TURBO Pascal, but assembler is acceptable. Can someone tell me how to do this (or does someone have a code fragment I can look at)? Thanks, Paul Young, K1XM --------
aptr@ur-tut.UUCP (The Wumpus) (05/02/86)
In article <388@brl-smoke.ARPA> YOUNG@dec-marlboro.ARPA writes: >I have an old XEROX 820-II which I am using for packet radio purposes. >I would like to use DTR/DTS on the serial port. I'd >prefer to do it in TURBO Pascal, but assembler is acceptable. Can >someone tell me how to do this (or does someone have a code fragment >I can look at)? > Forgive me for posting this respons, but our mailer (conservatively) stinks... You know something is wrong when it is easier to send from BITNET to UUCP then from UUCP to UUCP. Well, you come to the right place... First question: Which I/O port(s)? There are several usable I/O ports including 2 serial and 2 parrellel. (not to ntion the I/O bus) If you are really deperate, and can trash the disk drives (ie. go super-dedicated and burn PROMs) you can use two more parrellel ports that the Disk Drive Controller uses. (I don't really recommend this approach.) For using the DTR/DTS on the serial ports, those lines can be hardware jumpered to do either function to allow both port to be used for DTE and/or DCE equipment. The information on how to change the settings is in the book mentioned below. Access to them is actually best left to going through CP/m since it is easier then using assembly routines. You can you BOIS calls to do the communication, or even output to the serial ports from the ports on the z80. Again, more information is available in the book. As to where to get information about them. Xerox publishes (or atleast used to) the "Xerox 16/8 PC Technical Refrence Manual". It isshould be available from your nearest service center. Don't be scared off because it says "16/8" instead of "820-II" because they are the same machine, except for the addition of a seperate 8086 processor board in the expansion bus on the "16/8". Everything in the manual that doesn't concern the 8086 dual-processor is valid for the 820-II. If you have any other questions about the 820-II, send me e-mail. I have two of them in my basement at home. The Wumpus UUCP: allegra!rochester!ur-tut!aptr BITNET: aptrccss@uorvm