22 Mar
2017
22 Mar
'17
5:15 p.m.
On 3/22/2017 5:03 PM, Don North wrote:
On 3/22/2017 4:25 PM, Bill Gunshannon wrote:
Just checked my stock ... I have (5) 8641 based PCB, and (10) 2n7k based PCB
left, and corresponding microSD adapters.
The 2n7K vs 8641 designs are functionally compatible (100% same software); the
revised 2n7K design uses discrete transistor O.C. drivers and
HCT14 RCVRs in place of the 3x8641 (which are more or less unobtanium at this
point, unless you have a well stocked DEC stockroom).
The two designs work the same, there is no discernible difference between them
operationally.
As an aside I source Arduino Mega2560s from Amazon, you can get 100% a 100%
compatible clone for $10-$12 vs $45 for a 'genuine' Arduino Mega2560.
Don
Look here:
http://www.vcfed.org/forum/blog.php?12663-AK6DN for info on my
Arduino based RX02 emulator using a microSD card.
Works on RX11/RXV11/RX8E as RX01, RX211/RXV21/RX28 as RX02. Passes DEC
hardware diagnostics.
Reinhard has done an FPGA based RL01/2 drive emulator, see:
http://www.pdp11gy.com/indexE.html#file:///E:/homepage/indexE.html
Don
aka AK6DN
______________________________________________
I saw that. I ordered a set of boards from OSHPark today. Once they come I
will see about ordering the
parts and building at least one. I may wish I had more controillers. :-)
I will take a look at the FPGA solution. But I still have to ask, is there
any reason why it could not be done
with an Arduimo like the RX emulator? I haven't researched it deeply, but I
never thought the RL drive
itnerface was all that complex.
bill
If you are still interested I still have blank PCBs for $10 each (either 2n7K
or 8641 based), plus Sparkfun microSD adapters $5 ea, and then shipping.
OSHpark is good (I use them for proto) but it will cost you something like $75
for three boards since they are 4 layer. Let me know if you are interested.
The RL0x interface is very different and requires some kind of high speed
signal decoder to implement (Reinhard did it in an FPGA plus an embedded CPU).
The RX0x interface is driven by the drive as the master, so no high speed
logic is required on the Arduino side, just bit banging I/O ports.
Don