vr0z05@unido.UUCP (08/08/85)
[This line for the old byte eater]
I need help with AT-02!!!
Hooray,
it took 9 months to get our baby (the AT-02), but now we're very happy
and proud parents. But there still remain some questions.
Our authorized IBM-Dealer is not able to sell us the Technical Reference
Manual for the AT. He says that he hasn't got any form Big Blue. But I
have to adapt a selfmade communications program from our former XT to the
AT. Thinking that the AT is upward compatible I tried to put my
communications cable into the AT, but !!! STOP !!! the old Canon DB-25
is replaced by a Canon DB-9 plug. What now? We have no circuit diagram
how the DB-9 plug is configured. Is anybody out there in net-land able
to send me this configuration plan by E-mail???
Also I have realized that the programming of the RS-232 interface must
be a little bit different to the former XT. But I couldn't find out
what has changed. A testprogram which shortens input and output of the
RS-232 via the Modem Control Register (Bit 4 in $3FC set) and that ran
correct on the XT doesn't do anything on the AT. I can send a character,
I'm able to receive him via polling, the 8250 (is it really a 8250???)
produces an interrupt ($04 in $3FA), but the processor never receives the
interrupt, though I have set Bit 3 in the Modem Control Register (for OUT2)
and Bit 4 on Port $21 (the 8259, again: is there a 8259 in the AT???) in
order to allow interrupts. What is wrong.
Please help!!!
Many thanks in advance.
Uwe Hoch
Computer Science Department, University of Dortmund
4600 Dortmund 50, P.O. Box 500500, W.-Germany
E-mail address UUCP: ...ihnp4!hpfcla!hpbbn!unido!vr0z05bill@absolut.UUCP (08/11/85)
***** absolut:net.micro.pc / unido!vr0z05 / 12:06 am Aug 8, 1985 >Also I have realized that the programming of the RS-232 interface must >be a little bit different to the former XT. But I couldn't find out >what has changed. A testprogram which shortens input and output of the >RS-232 via the Modem Control Register (Bit 4 in $3FC set) and that ran >correct on the XT doesn't do anything on the AT. I can send a character, >I'm able to receive him via polling, the 8250 (is it really a 8250???) >produces an interrupt ($04 in $3FA), but the processor never receives the >interrupt, though I have set Bit 3 in the Modem Control Register (for OUT2) >and Bit 4 on Port $21 (the 8259, again: is there a 8259 in the AT???) in >order to allow interrupts. What is wrong. > > Please help!!! > Many thanks in advance. ---------- The following are the pinouts for the PC-AT Serial Port 1=Carrier Detect 2=Receive Data 3=Transmit Data 4=Data Terminal Ready 5=Signal Ground 6=Request to Send 8=Clear to send 9=Ring Indicator The above are for the 9 pin DB connector Source = uucp network According to the PC Xenix manual the AT is configured as a DTE. Hope this helps. Bill William Gibbs {ucbvax!cbosgd!ima!cfib}\ 46 Bryon Rd. Apt 5 !absolut!atgibbs!bill Chestnut Hill, MA 02167 {decvax!cca}/ (617) 325-7482