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Is there an RX01 Emulator?

RichCini

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All --

Since I've gotten my Heathkit H-11 running RT-11 (both v4 and v5) using the TU58 Emulator, I'm looking to extend the flexibility (and improve the speed) by adding an RXV11 controller. RX01 drives are obviously very large, and I don't have the space for them so I was hoping that a hardware-based RX01-equivalent to this TU58 emulator (http://www.torok.info/computing/pdp11/tu58/) exists somewhere.

I'm also considering changing the SLU from the Heath version (limited to 9600 baud) to the DLV11-J so I can get 38.4k on the tape interface.

Thanks!
 

glitch

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I don't remember if it was an RX01 or RX02 emulator, but there does exist an emulator which uses a PC parallel port connected to the RX controller.
 

AK6DN

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All --

Since I've gotten my Heathkit H-11 running RT-11 (both v4 and v5) using the TU58 Emulator, I'm looking to extend the flexibility (and improve the speed) by adding an RXV11 controller. RX01 drives are obviously very large, and I don't have the space for them so I was hoping that a hardware-based RX01-equivalent to this TU58 emulator (http://www.torok.info/computing/pdp11/tu58/) exists somewhere.

I'm also considering changing the SLU from the Heath version (limited to 9600 baud) to the DLV11-J so I can get 38.4k on the tape interface.

Thanks!

There is this: http://www.chdickman.com/rx02/ read down the page aways.

Getting a serial card and modifying the UART and timing logic to allow 115.2Kbaud operation makes TU58EM about on par with the RX floppy drive. Transfer rate is not quite as fast, but TU58EM makes up for it in having an effectively zero seek time. I did this mod to a DL11-W (single port serial card) for the UNIBUS by replacing the original 40P UART with a more recent version capable of 115.2K operation, and changing the master timing oscillator and divider chain to generate the correct clock rate. TU58 storage size is as least as good as RX02, and up to 3xRL02 capacity if you are willing to do a device driver patch. I modified my DL11-W for about $20 in parts.

That being said, another approach is to go with a QBUS SCSI card ($200-$400, depending) and a SCSI2SD emulator ($60). This will give you a lot more flexibility to run just about any DEC operating system by just swapping SD cards (or not even, given that the most recent SCSI2SD emulator can act as four SCSI device targets at once). SCSI2SD info here: http://www.codesrc.com/mediawiki/index.php?title=SCSI2SD

Don
 
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RichCini

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Searching for that produces this page http://www.chdickman.com/rx02/ which refers to "rxm" but there haven't been any updates since 2012. Let me ping the owner and check...I'll report back.

...ha ha. Don, your post went up at the same time as mine so I didn't see it. Thanks for the info on the SCSI option. Do you happen to know or can you recommend a good SCSI controller?

Thanks!

Rich
 
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gslick

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Do you happen to know or can you recommend a good SCSI controller?

Thanks!

Rich

The more common Q-bus MSCP SCSI choices include:
CMD CQD-200, CQD-220
Dilog SQ706
Emulex UC07

I have one or more of each and they all seem to work equally well for the most part.

One advantage of the CMD CQD-200 and CQD-220 is that they can do both MSCP and TMSCP with a single controller if you have the /TM firmware installed.

-Glen
 

AK6DN

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I have both an Emulex UC17 (one MSCP port) UNIBUS controller on my 11/34, and an Emulex UC18 (one MSCP port, one TMSCP port) on my 11/44. Both have been reliable and trouble free since I have had them (for about four years or so). UNIBUS SCSI is very pricey compared to QBUS SCSI (for no reason other than scarcity) but I was able to get reasonable deals on these cards at the time. I have no experience with any other UNIBUS SCSI controllers (like the CMD series).

Don
 

smp

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Hi Rich,

I have the Emulex UC07 in my PDP-11/23, and it works like a champ. I paid a pretty penny for it, something like $249 IIRC, but it was well worth it in the long run.

Good luck...

smp
 

gslick

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UNIBUS SCSI is very pricey compared to QBUS SCSI (for no reason other than scarcity) but I was able to get reasonable deals on these cards at the time.
Don

That is for sure. Within the last week eBay buyer e***c went on a spree and bought a couple pricey UNIBUS SCSI controllers:

CMD CDU-720/TM $1,100
http://www.ebay.com/itm/300082063055?orig_cvip=true

Emulex UC17 $949 (best offer was accepted for unknown amount)
http://www.ebay.com/itm/141009288312?orig_cvip=true

I have a couple of CMD CDU-720/M but currently no UNIBUS system to put them in. Some day I'd like to pick up an 11/44 again, although I suppose that won't happen until after I eventually give up and decide to sell the CDU-720/M.

-Glen
 

RichCini

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Glen, et. al. --

Today I received the UC07 I purchased (UC07 rev. H, PCB revision D dated 1990, ROM code G143R). Physically it looks to be in excellent shape. I haven't read the manual yet, but is there a preferred setup for the DIP switches/jumpers?

Separately, I also received the SCSI2SD with 256MB card. So, I have something to play with this weekend :)

Rich
 

gslick

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I didn't change any jumper or switch settings on the UC07 I received. They were all at the factory defaults listed in the manual and that was fine for my use. You probably only need to bother if you have another controller at the default MSCP address.

I don't remember if there is an 18-bit/22-bit option that might apply in your case with an 18-bit backplane.

-Glen
 

RichCini

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What would be a good drive size to use for this? I have a 256MB SD card, so I was thinking of two partitions equivalent to the RZ23 (104MB each) or RZ23L (121MB). Any thoughts?

Rich
 

gslick

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What would be a good drive size to use for this? I have a 256MB SD card, so I was thinking of two partitions equivalent to the RZ23 (104MB each) or RZ23L (121MB). Any thoughts?

Rich

I don't know if there is too much point in matching the exact size of an RZ-series SCSI drive for use with a PDP-11 system. There might not be any software that has any special knowledge of those particular sizes.

If I was going to match the exact size of known drives I might pick an RD54 at 311,200 blocks / 159,334,400 bytes although you couldn't fit two of those in a 256MB SD card. Or maybe an RD53 at 138,672 blocks / 71,000,064 bytes

Even 2.11BSD with full source installed easily fits on an RD54. That's not a option for you if you only have an 11/03 or 11/23 CPU, and I believe 2.9BSD does not have MSCP support. Most other PDP-11 OS of interest use a lot less disk space.
 

RichCini

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Yeah, Glen, good point. I haven't yet run the software on the SCSI2SD to configure the LUNs but I figured that I'd make it look like something "standard" if I could.

Is there a list of "standard" hard drives anywhere? I thought I saw this come up somewhere on one of the lists recently but for the life of me I can't find it.

Thanks!
 

Lou - N2MIY

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Bela,

At first glance, this looks fantastic! I look forward to studying your work and building one of these. I built your Arduino based TU58 emulator and it works very well. I may ask you some questions as I get into it.

Lou
 

Lou - N2MIY

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Folks,

I built Bela's RX02 emulator : http://www.vcfed.org/forum/album.php?albumid=341&attachmentid=32765 . I have it working somewhat on the VT278, but no luck yet on the RX8E or RXV21. I didn't try the RX11 since it wasn't convenient. On the Decmate, I can boot and read RX01 and RX02 disks with no problem, however writing is problematic. I can only write properly to RX01s in bytemode format. I can't even read on the 11 or 8. I think it's time to haul out the logic analyzer and see what the deal is. I've rechecked all the wiring/resistors/connector pinning/2N7000 operation (read they are static sensitive) but that is all good. It must be software!

Here are a few more photos of the build:
http://www.vcfed.org/forum/album.php?albumid=341&attachmentid=32768
http://www.vcfed.org/forum/album.php?albumid=341&attachmentid=32769
http://www.vcfed.org/forum/album.php?albumid=341&attachmentid=32764

I used an Arduino Mega protoshield as Bela did. It is perfect because it has a DIP area for the 74HC00 and surface mount area for the 74LVC14. There is just enough room otherwise for the six 2N7000s and the 180/390 ohm resistors and 40 pin header. The Due at 3.3V is somewhat convenient because the SD card is 3.3V. The 3.3V high level still satisfies the 5V TTL inputs of the LCD, so that is good. I put a DB25F on the back like a teacart RX02 and also a 40 pin female header just like the normal rackmount RX02.

Has anyone else built this yet and have any experiences to share?


Lou
 
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