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Re: Econet podule for RISCPC & A7000

Posted: Tue Sep 29, 2015 6:31 pm
by danielj
5.76 :?

Re: Econet podule for RISCPC & A7000

Posted: Tue Sep 29, 2015 9:54 pm
by IanB
What clock speed is your StrongArm?

Re: Econet podule for RISCPC & A7000

Posted: Tue Sep 29, 2015 9:57 pm
by danielj
200mhz :?

d.

Re: Econet podule for RISCPC & A7000

Posted: Wed Sep 30, 2015 12:25 am
by IanB
What type of client machines have problems? (e.g. bbc micro / A5000 etc)

What sort of Econet clock are you using and what is the exact clock speed?
I think 200Khz is the maximum I tested. Have you tried reducing the Econet clock speed as it's possible another delay needs to be added somewhere in the code when running the network at the maximum clocks speed.

Re: Econet podule for RISCPC & A7000

Posted: Wed Sep 30, 2015 5:25 am
by danielj
RiscPC, A3020, Master and BBC micro. I'm running at 250khz off a beebmaster clock (period 4us, Mark 1us at the mo). I'll try it with a reduced speed this evening and see if that improves things! I'm probably running at the limit of what the beebs and masters like anyway, but they are happy with the A3020 file serving.

Thanks for picking this up :)

d.

Re: Econet podule for RISCPC & A7000

Posted: Wed Sep 30, 2015 7:03 pm
by danielj
Okay. Works fine at 200kHz, garbage at 250kHz, dipping slightly from that to 235kHz is also fine. :)

I'm happy running at that sort of speed, but interested to see what's going on if you do want to work out where the issue is :)

d.

Re: Econet podule for RISCPC & A7000

Posted: Wed Sep 30, 2015 10:20 pm
by IanB
Well I think Acorn recommended 200Khz max as 250Khz was marginal under certain circumstances.
e.g. When using a 6502 second processor 200Khz was the limit.

However, the likely problem in this case is that the turnaround time is too fast.
i.e. the RISC PC with StrongArm is likely replying to packets so fast that the BBC hasn't got enough time to get ready to receive after sending a transmission. Slowing the clock gives just enough breathing room.
Does the A3020 work with the RISCPC at 250Khz?