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Booting Pdp-11 from flash USB

C

Crawford

Experienced Member
Joined
Oct 21, 2008
Messages
275
Location
Maryland
Folks,

Not to steal thunder from Chuck(G), but I have successfully booted my 11/53 from a USB flash stick.

It was actually pretty easy, starting with a cheap (24 USD shipped) Gotek floppy emulator from ebay http://www.ebay.com/itm/281215864477?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

The emulator was attached to a Rqdx3 board, which recognized it as a rx33. I plugged in a 2gb sony flash stick and formatted by powering it on with both buttons pressed. It formatted 1000 virtual floppy images on the stick. I then booted xxdp, and used zrqch0 to format the 'floppy', initialize du1:, copy/boot du0: du1:, copy/files du0: du1: and I had a bootable flash drive.

I haven't tried capturing the disk image from flash or inserting my own images yet. But it does work out of the box for this particular 1.44mb emulator...

? ; - )
 
Last edited:
Crawford said:
Folks,

Not to steal thunder from Chuck(G), but I have successfully booted my 11/53 from a USB flash stick.

It was actually pretty easy, starting with a cheap (24 USD shipped) Gotek floppy emulator from ebay http://www.ebay.com/itm/281215864477?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

The emulator was attached to a Rqdx3 board, which recognized it as a rx33. I plugged in a 2gb sony flash stick and formatted by powering it on with both buttons pressed. It formatted 1000 virtual floppy images on the stick. I then booted xxdp, and used zrqch0 to format the 'floppy', initialize du1:, copy/boot du0: du1:, copy/files du0: du1: and I had a bootable flash drive.

I haven't tried capturing the disk image from flash or inserting my own images yet. But it does work out of the box for this particular 1.44mb emulator...

? ; - )
Click to expand...
Very interesting.
 
I wonder if there is a way of putting a bootable image on a pen drive from a PC and booting the PDP from this? I've just ordered one of these gizmos from a UK supplier;)
 
Ok, bought one too. This is too cheap not to play with, especially since you've proven it to work.

I am interested to see the file format for the disk image files. I hope I can reverse engineer it to make conversion programs (like I did for Reinhard's RL02 emulator) so that the disk images can be worked in PUTR.

I am interested to see if this could work as an RX50. If so, it could be used on a decmate II or pro....

Lou
 
Lou - N2MIY said:
Ok, bought one too. This is too cheap not to play with, especially since you've proven it to work.

I am interested to see the file format for the disk image files. I hope I can reverse engineer it to make conversion programs (like I did for Reinhard's RL02 emulator) so that the disk images can be worked in PUTR.

I am interested to see if this could work as an RX50. If so, it could be used on a decmate II or pro....

Lou
Click to expand...
Heck, I even ordered one.
 
Lou, Tim,

Glad to have you on board. Chuck(g) has been working on one of these (see his blog entries).

Lou - I think that RX01's are out of the question, one of the bloggers said it would not emulate 360RPM or 1.2MB which I think are the magic numbers for the 5.25 disks . Check Chuck's blog for my links on this. (these are popular for old synths and embroidery/CNC machines apparently)

The utilities for these things are pretty bad. I think that Chuck(g) verified that the 'formatting' is just allocating 1.44MB times the number that will fit on the flash drive. What I mean is that this is not FAT formatted or anything like that, it's just using it as a block device. I tried to use the IPCAS software, which did the format, but the drive was used (after format), the IPCAS s/w would freez when trying to access the flash stick.

I am definitely digging out my small (less than 1GB) drives to use until we get some reliable utilities...

- C
 
I just read Chuck's blog entries on this unit. It does seem that RX01 is out of the question (only 18 sectors per track is supported).

Although the USB memory stick will not be FAT formatted, all is not lost. Because the disk emulator looks like a real drive to ImageDisk (it should!), that will be the means to work with the USB memory stick on the PC. This may mean for convenience getting another one of these to leave in a PC, while the other goes in the 11.

Lou
 
Folks,

Minor progress last night. I got RT11 installed as virtual floppy #1 on my flash drive. I copied the files from an MFM disk used to boot the 11/53. So, xxdp is floppy #0 and rt11 is the second image. No good utilities (yet) for moving the images on and off in bulk.

? ; - )
 
My drive came in the mail today. The stock seems to be in Brooklyn, which explains why it came so fast.

Unlike the unit in the ebay photo, mine has three seven segment displays. From everything I have read on the internet, this is the version capable of 1000 floppy images. Is this what you got Tim and Crawford? The PCB says SFRC922 to the right of the jumper area.

I'll play with it this weekend. It will be fun.

Lou
 
Mine came today as well - Brooklyn NY. Anyone taken it out of the box yet? [ok - yeah... I know, don't say it] What's the internal red LED for?

It's an ARM 128K STM32F105RB

What's on the disk?
 
The disk had some documentation and software utilities. The documentation seems to cover a variety of models. I wish there were some markings to show exactly which model we received. Some of the software utilities do appear to suggest that some versions of this device may record to FAT formatted USB memory sticks.

The chinese and english documentation look equivalent. There doesn't look to be any hidden tips in the chinese files that aren't in the english ones.

Lou
 
Hi All;
Is there any way that these could work with the older UniBus machines, like my 11/40 and 11/45, or is there No Controller for the UniBus, But only the QBus machines ??
THANK YOU Marty
 
Lou - N2MIY said:
My drive came in the mail today. The stock seems to be in Brooklyn, which explains why it came so fast.

Unlike the unit in the ebay photo, mine has three seven segment displays. From everything I have read on the internet, this is the version capable of 1000 floppy images. Is this what you got Tim and Crawford? The PCB says SFRC922 to the right of the jumper area.

I'll play with it this weekend. It will be fun.

Lou
Click to expand...
From your description that is what I got too. I am reading about it now. Had to scrounge up a floppy cable which I didn't think
I had and had to borrow a USB cable from something else. I have not tried it yet.
 
@Lou - yes I have that model, numbers match

@Marty - no, I am not aware of an equivalent to the RQDX3 for unibus , sorry.

@Tim - why would you need a USB cable? I just plugged the flash into the front of the drive...
 
Crawford said:
@Lou - yes I have that model, numbers match

@Marty - no, I am not aware of an equivalent to the RQDX3 for unibus , sorry.

@Tim - why would you need a USB cable? I just plugged the flash into the front of the drive...
Click to expand...

I hadn't yet read how to use. I just assume the USB plug in front was for a USB cable.
 
Lou,

I'm pretty sure the model we got is SFR1M44-U100K , meaning that it does not do the download (DL model) from thumb drive to internal flash ... But that could just be firmware differences between the models. BTW, I noticed the picture changed on the ebay site... Now it shows a 2 digit display. Buyer beware as always.

? ; - )
 
Well, I got mine up and running tonight. I used the internal formatting routine (hold both buttons in on powerup) and the USB stick got reformatted for the 1000 floppy partitons. I had a real RX33 connected as DU1: and the emulator as DU0:. I booted XXDP from DU1: (an RX50 floppy in the RX33 drive) then used ZRQC?? to format the first 20 "floppies" on DU0: (one at a time, of course). Then I made the first one a bootable DUDP image, and the second a bootable RT-11 V5.3 image. They both worked fine. It seems to be faster than the real RX33 (must be the seek time).

The utilities that came on the little CD appear to be useless. I have not tried further to figure out how to look at this USB memory stick. Copying floppies is slow, so we need to figure out how to work with this in PUTR, or copy imagedisk images to the partitions. Otherwise I will need to buy another emulator to put in the PC.

Lou
 
So I had some progress with splitting and recombining files (disk images).

I formatted a few partitions on the flash disk (rt11 and xxdp), remembering where they were. I imaged the whole flash disk using win image. Best to use little flash disks, folks!

Then I used HxD to split out the images using the magic size of 1572864, which one of the aforementioned blog sites derived. That gives you as many 1.5 meg slices as your flash disk (told you to use a small flash). Only the first couple matter, so delete the rest. Perhaps save one blank for testing.

I then used HxD file merge to make an image with the floppy images in a different order for verification and wrote down the order. Saved that as stick2.img and used win image to dump that back on another stick.

Voila! The images boot if you select the right ones and remember to start counting at zero.

Sort of a pain but it does work.
 
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