On Sat, 18 Jan 2014 12:00:01 -0600, you wrote:
From: Jonathan
Katz <jon at jonworld.com>
On Sat, Jan 18, 2014 at 10:22 AM, Charles
<charlesmorris800 at centurytel.net> wrote:
I have an ancient (AMD K6, 300 MHz, Win XP)
desktop PC that I am
trying to use to download RL02 diagnostics to my PDP-8/A via the TTY
console port (20 ma current loop).
Not familiar with this at all, but two things.
1) I remember being able to set IRQs on PCI slots in this era of
systems. Maybe you need to play with that?
2) Have you tried a protocol other than current loop on this ISA card
(like RS-232) to another system to see if it works?
I suspect you are right - that the card is somehow not signaling the PC that it is ready
to accept data. But there are no IRQ conflicts (card is jumpered to 12 and Windows is
unaware of anything else using 12, or address 0210-7). The existing serial ports are on
03F8, IRQ5 and so forth. Although the PCI slots do have a "plug & play/Auto"
setting, I removed every card except this one and the problem is still there!
Yes, I have tried RS-232. The problem is not the line drivers/receivers... no data is
appearing at the UART's TxD pin regardless of which set of buffers it then goes to.
And as I noted, I did hard-wire the RTS, CTS, DTR lines and they are being sensed, and do
not appear to be telling the port to hold off.
This card has a controller chip by Lattice and the UART (and a small amount of glue
logic). No schematic information of course.
Will keep trying. Thanks for the help.
From: Jonathan
Katz <jon at jonworld.com>
On Sat, Jan 18, 2014 at 10:22 AM, Charles
<charlesmorris800 at centurytel.net> wrote:
I have an ancient (AMD K6, 300 MHz, Win XP)
desktop PC that I am
trying to use to download RL02 diagnostics to my PDP-8/A via the TTY
console port (20 ma current loop).
Not familiar with this at all, but two things.
1) I remember being able to set IRQs on PCI slots in this era of
systems. Maybe you need to play with that?
2) Have you tried a protocol other than current loop on this ISA card
(like RS-232) to another system to see if it works?
I suspect you are right - that the card is somehow not signaling the PC that it is ready
to accept data. But there are no IRQ conflicts (card is jumpered to 12 and Windows is
unaware of anything else using 12, or address 0210-7). The existing serial ports are on
03F8, IRQ5 and so forth. Although the PCI slots do have a "plug & play/Auto"
setting, I removed every card except this one and the problem is still there!
Yes, I have tried RS-232. The problem is not the line drivers/receivers... no data is
appearing at the UART's TxD pin regardless of which set of buffers it then goes to.
And as I noted, I did hard-wire the RTS, CTS, DTR lines and they are being sensed, and do
not appear to be telling the port to hold off.
This card has a controller chip by Lattice and the UART (and a small amount of glue
logic). No schematic information of course.
Will keep trying. Thanks for the help.
I got it working at last! Changed the card (and COM3 port) settings to
IRQ5 and it sends and receives through a loopback test of the current
loop interface. Tx and Rx lights are flickering, and my trusty Tek
scope shows a nice 110 baud data stream in the current loop :)
Yet another multi-hour casualty of Microsoft legacy software. No idea
why it wouldn't work on IRQ12 with all other cards removed and the
onboard hardware not using that interrupt. Sigh.
Now to figure out how to download the RL diagnostics, which are binary
files! Hopefully it will be as simple as COPY AJRLxx.BN/B COM3: but we
shall see.
... and of course I need the BIN loader running on the 8/A (unless
those files are in RIM format?) Anyone know?
-Charles