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RL02/RL01 simulator project is finished

PDP11GY

PDP11GY

Experienced Member
Joined
Jun 20, 2009
Messages
144
Location
Munich/Germany
Hallo,
I have a good new message. The RL02/RL01 disk drive simulator
based on the DE0-Nano board is up and running. This implementation
provides full flash support and full FAT32 SD-Card support. In
other words, we will be now be able to share all RL01/Rl02 based
software worldwide. I would be very happy if we can work together.
You can download now the entire project from my homepage direct
because FAFNER is replaced through a AlphaServer. In the project kit
is a RL02 image included which contains a bootable
RT-11XM (S) V05.04 C system with RT-11 BASIC.
Regards, Reinhard
 
Interesting work, am studying what you have accomplished intently with the idea of trying to duplicate it. Looks like you have about a dozen I/O lines between the ED1 board and interface to the RL data bus. I have no experience with the ED1 or working with FPGA bus structure but going to assume that the ports on the board are direct I/O and not something like a parallel port? And would wonder if the same code can be run under an emulator on a PC using a parallel port with the same results? Or are the requirements beyond the capability of a PC parallel port? Sorry to appear a bit dense about this but my education was not much beyond the Basic Stamp and not up to date when dealing the latest technology.
 
Reinhard,

This is really a fantastic piece of work! I just read the readme file, and what you have accomplished is very impressive. I have downloaded your files and will build one of these. Not only would I be intersted using this on the 11, but also with my RL8A controller on my 8/e. Moving files on the 8/e is quite slow since I either have to use RX01 or send over a serial line. It would be very useful to move a whole RL02 OS/8 image as simply as with an SD card!

It looks like this project can be built for about $100USD, which is quite reasonable.

If you do work on the ST506 emulator, would you continue to use the DE0 board for the development? That way those of us who buy DE0 boards for the RL02 emulator can re-use most of the investment.

It will take me a few weeks to accumulate the parts, but I will certainly let you know how it goes.

Thanks again for your hard work!

Lou
 
Lou,
thank you very much for your feedback.
It's a great idea that you're using the RL simulator also in the PDP-8 environment.
The Computer Museum in Munich has unfortunately no Rl8A controller so that you
can now perform this important task. Great !, to get an OS/8 image on SD-Card.
You are right, this project can be built for about $100USD. In Germany, it was
not so easy to get the 75113 + 75107 bus driver/receiver chips but I think, that
should be no problem. Parallel I continue working on ST506/St412 project and also
here, I use the DE0-Nano board. So, it will become my/our standard. Perhaps a PCB board
will be developed ( PCB123 Design Software) but this is primary a question of
money. I've been already thinking about follow-up projects like using a PC or the
RASPBERRY PI computer, install a PDP-11 or PDP-8 simulator and run the code
from the images on the SD-Card, generated by the RL-simulator. But this is realy
a question of time, may be possible when I'm retired or other people feel attracted.
In my project some improvements are planned. I will load them on my hompage, current
Version is V3.02. Wish you good succeed and have fun,
Reinhard
 
Very cool! Much cheaper than I would have expected. When my RL drives cave in I'll keep this in mind :)

Good work Reinhard!
 
Pontus,

BEFORE your RL drives cave is the right time to think about this project. I intend to backup everything with this since it will really make the job easy. The real RL drive as drive 0 and Reinhard's drive as drive 1, then a block by block copy.

Lou
 
So it appears you are taking a data file off SD card and producing all the low level formatting information in the emulator like correct sector gaps, preambles, related patterns, etc. Why wouldn't a more generic PCM recorder/playback design work? .. coupled with a low level file format converter?
 
Lou - N2MIY said:
Pontus,

BEFORE your RL drives cave is the right time to think about this project. I intend to backup everything with this since it will really make the job easy. The real RL drive as drive 0 and Reinhard's drive as drive 1, then a block by block copy.

Lou
Click to expand...

You make a good point :) I doubt I have any unique stuff on my RL packs. (well unless there is a GAMMA-11 pack somewhere)
 
Thank you for all diskusions points.
The project is open like open source and every improvement, add-ons and
comment is welcome. You also can build in your personal changes but we
should NOT make any changes in the data structure, otherwise the RL-images
will be incompatible and we can't exchange it.
@Lou Please correct me if I am wrong. As far as I know, you can't copy
block by block ( RT-11 : copy/device ) because you can't copy bad blocks
and to my knowledge a block by block copy does not read the bad sector
file tO take care of it. A smart solution would be a disk clone implementation.
My plan was, connect a RL drive direct to the DE0 and copy the whole disk to the
SD-Card without any host support. From the perspective of FPGA firmware and
software it would be relatively easy to implement it and we would not need
consider about which software is on the source cartridge ....But I have no
desire, patience and time yet to solder/wire-wrap another add-on board.
Sorry, that's not my intensity but maybe someone other can take this challenge?
@eeguru You are right. I reconstruct the cartridge format in FPGA, like
sector-puls, preambles, Header, CRC's and data to give the RL-controller
the illusion that a 100% alligned and error-free cartridge is inserted.
@PG31 I agree, a PCB would be fine. Any idea who can do this? Maybe we
should find a sponsor, such as the computer museums or Altera?

One additional info: The manufacturer of the DE0-Nano Board, Terasic has
changed the EPCS flash chip manufacturer and there was a problem. More details
and a simple fix is available on: http://www.alteraforum.com/forum/showthread.php?t=38703

Reinhard
 
If you plan a generic MFM/RLL emulator, could you just implement a PCM recorder in the FPGA then put down sector marks with a low level format utility from the host?
 
Excellent! I've been watching Reinhard's work and waiting for the DE0 rev. Now that it's done, I'll build one too. I'd like to have a PCB since I can use a couple of them on various systems, but in this case, I'll tailgate on Lou's work and try to follow along. First step will be to simply combine the two proto-boards into one, but since I've never built on perf board before, I'm just shadowing on this one.

This is a wonderful project and combined with the ST project, has long been needed by the vintage community.

Thanks Reinhard!

Jack
 
I would pay someone to build one of these for me; I've got an 11/34a and an lsi11/73 that I hook up to a pair of real RL02 drives, and having a small unit for backup -- or to run RT11/RSTS on - would save me a whack of electric bills.

I'd be willing to offer $300 for a working unit.
 
Folks,

My parts are on order. If anyone in north america is interested, Newark had the best price on the DE0 Nano board (and if anyone knows otherwise they should let us know) and also had the TI 75107B and 75113s in stock. Basically the whole bill of materials can be gotten from Newark.

I may keep Reinhard's two wire-wrap board design. One of the boards has the SDcard socket and MAX232 console driver/receiver. The other board has the RL specific hardware. The SDcard and console connection would probably be useful for any later projects like an ST506 emulator. Then simply the RL hardware board could be unplugged and the ST506 specifc interface board could be plugged in.

Lou
 
Folks,
you also can use both 40pin connector from the DE0-Nano board.
One connector would be responsible for the UART/serial I/O and
for the SD-Card and if desired for some LED's and/or display ?
The other connector will be used only for I/O signals. SD-Card
and UART only needs 6 pins. The pin Assignment can be done
easily with the PIN-planner. I can not change back because I
have already done it like you can see in my pictures.
Reinhard
 
Folks,

I have been making slow but steady progress building Reinhard's RL02 emulator. I am not usually good about taking progress photos, but I have taken some this weekend.

This is the top view looking into the enclosure: http://www.vintage-computer.com/vcforum/album.php?albumid=184&attachmentid=12234 . I have built a linear power supply into the side of the case with 7805 and 7905. The perfboard is the adapter between the DE0 Nano and the rest of the world. It has the RL drive interface ICs, MAX232 (for the debug console interface) and the SDcard header. The DE0 Nano is still in its plastic bag. I did not power it up yet, but will do so when I'm done wiring the perfboard. At this time the perfboard is about 50% done. All the grounds and +5 is routed, all decoupling caps mounted and wired, the 5V to 3.3V voltage dividers wired, and 1uF MAX232 caps installed. Whats left is the actual point-to-point wirewrapping. All that is/will be hidden under the board as this is old-school longtail socket wire wrapping.

This is a view from where the front panel will be someday: http://www.vintage-computer.com/vcforum/album.php?albumid=184&attachmentid=12236 . I will not build a front panel until I play for a while. I intend to bring the DE0 Nano's button, switch, and LED functions out through the GPIO1 header and put them all on the front panel. I'll also make a slot on the front panel to receive the SD card. In the mean time, I have brought out the power supply switch leads and soldered them closed, and plugged my SD card adapter into the perfboard : http://www.vintage-computer.com/vcforum/album.php?albumid=184&attachmentid=12237 . When I make the front panel, I'll use a 10 pin header connector cable to go from the perfboard to the panel mounted SDcard socket. This is my first time doing anything with an SD card socket. The one I arbitrarily picked worked out pretty good.

This is the back panel: http://www.vintage-computer.com/vcforum/album.php?albumid=184&attachmentid=12235 . The RL drive connectors are borrowed from my RL01 with the busted heads. They are oriented just like on a real RL drive, cable exiting left. The DB25 is the debug console connection.

Perhaps in another week or so, I'll be ready to power up. I've already tested the +/-5V supply, so that much is good. I'm looking forward to trying this on the RL8A!

Lou
 
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Reinhard,

I am making good progress. I flashed the DE0 Nano just now using your "Getting Started Immediately" instructions. My DE0 nano board is new and uses the Spansion flash memory. So, I read your post on the Altera form and did copy the patch file from the Demonstation\EPCS_Patch directory of DE0-Nano System CD (that came in the box with the device) and put it in the directory altera\12.1\nios2eds\bin. I decided to download the Version 12.1 from the altera website and install that. It works fine.

So new the unit is flashed. It starts up fine and I have a VT420 connected as the console debug terminal and can see the output. I used a MAX232 5V device instead of the 3.3V MAX3232 devce. Of course I then put a 5V to 3.3V voltage divider on the output of the MAX232 so as not to hurt the DE0 Nano that has 3.3V inputs (the same way you had the 680/1K voltage dividers on all the line receiver outputs.

Progress photo is here: http://www.vintage-computer.com/vcforum/album.php?albumid=184&attachmentid=12295 . I also uploaded a photo of the front side and wiring side of the adapter board.

My board with the line drivers/receivers/MAX232/SDcard adapter is all wired, checked, and mounted. Now I will go to the store and get an SD card (ran out) to format and write the RL11 disk image to. I will first checkout the emulator on an 11 before moving to the RL8A.

Lou
 
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Lou,
thanks for the good new information.
I also did a look at your pictures.
very professionally done. My compliments!
I'm working on an update and I will inform you when it is available.
Also, there is still a problem if 2 RL02 drives operates simultaneously.
For example, DL0 is the real drive and DL1 is the simulated drive and you
hit the RT-11 command from a booted RD51, copy/sys Dl1:*.* DL0: , the
simulator will run in a problem. The Problem ist related to the match
signal in the verilog module "my_runnig". Currently I can not verify
the solution because my originally RL02 drive is broken, mechanical problem.

I will inform you as soon as possible.

Reinhard
 
Reinhard,

Well, we did work a bit this afternoon with the RL02 emulator both on the 11/53 with RLV12 and 8/e with RL8A. I did indeed experience the two drive trouble. The RLV12 handled it better than the RL8A did. Only now did I just read your post that this is a known problem. I was thinking perhaps I had done something wrong somewhere.

Here is a photo with the 11/53: http://www.vintage-computer.com/vcforum/album.php?albumid=184&attachmentid=12300 . The VT240 is the console terminal for the 11/53. The VT420 is the debug terminal on the emulated RL02. The 11/53 is in the tabletop BA23 under the debug terminal. The green towel is merely a dust cover for my LA50 underneath. The emulated RL02 is on top of the green towel. I used real RL02 cables and termiantors to chain everything together. I feared that the bad behavior was due to some kind of signal problems due to my wirewrapping and all these feet of RL drive cables/bulkhead adapters/etc.

Interstingly, whenever I did an RT11 DIR /BAD, I would get two bad blocks on your bootable RL02 RT11 V5.4 image. See here: http://www.vintage-computer.com/vcforum/album.php?albumid=184&attachmentid=12299 . It did this even if only one drive (the emulated one) was attached to the RLV12.

On the RL8A, I never tried working with only the emulator as the only connected RL02 drive. The problem there was quite strange. Although I could boot my usual boot pack, it would not load CCL.SV and so I had no concise command language. But it was still there. I could see it if I booted from RX01 and then looked at the directory on the RL02. I then also tried all of the RL02/RL8A diagnostics on the simulated drive, and even the real drive, and they failed. Perhaps I will try connecting the simulator by itself to the RL8A and build a bootable "pack" from floppy. First though I would retry the diagnostics. For information, I started with a blank pack image as drive 1, and then intended to use RL2FMT.SV to format it (the usual OS/8 way to format a RL02 pack).

I was wondering about the .DEC pack image format. It would be useful to have a conversion program that could take RL02 pack image files that work under PUTR and convert them to the .DEC format. For the heck of it, I did try to open one of the .DEC pack image files under PUTR, but it is not recognized (even with /RL02 /RT11 switches when mounting).

But for all this, it is pretty good so far and I am having fun.

Lou
 
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