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A PET storage option

bitfixer

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*snicker* I can just see it now... VINTAGE! **RARE PROTOTYPE** @@@BLAWBLAWBLAW@@@ ;^)
L@@K!

I was actually thinking of getting a second one if you still have boards. The guy I gave the chicklet 2001-8 to could use one.
Sure thing. I'm just about to run out of this group of boards, but I can get more in 2 days from the PCB house.
 

tezza

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Snatched a bit of time today to try out the PETDisk.

Loads and lists files just fine. Congratulations on a fine piece of hardware to add fun to our hobby. Getting the 5V from the cassette edge hence doing away with an extra power source is a great idea.

One thing, the PETDisk at present is read-only, yes (apologies if this has been mentioned before)? I can't seem to scratch files.

Tez
 

bitfixer

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Tez,

Thanks, I'm glad you got the chance to try it out.

Saving right now only supports short (8 character or less) file names
so
save "test",9 would work, save "a test file",9 currently does not work.
What was the file name you used when attempting to save?

One thing to try is:
- Reformat the sd card (FAT32)
- plug in PETdisk and turn on PET
- type in sample program
- SAVE "TEST",9

This process should hopefully work, if not there's something else going on.
What type of PET and BASIC were you using?
 

MikeS

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Same here, I'm afraid; I can load programs (and the directory) without problems but save "HELLO",9 (or 8 ) only goes through the motions (i.e. a respectable pause, no error) but nothing gets saved, alas (8032, BASIC 4). Locking/unlocking doesn't seem to make any difference.

Gonna try to get together with Steve next week and investigate further; I think he also has an issue saving and reloading on the C64, and it looks like the VIC needs expanded memory to use the IEEE interface and still have room for the directory listing.

Fun!
 
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tezza

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Oh, sorry. Saving worked just fine when I tried it so the device is obviously not read-only (duh!). My poor choice of words.

What I was referring to was deleting a file. Is that functionality available? I saved a file to the PETDisk calling it TESTFILE then tried to erase it. (No jumpers so assumes device 8 )

I've got BASIC 4.0, 32K. My machine is a CBM 3032. As per the "PET/CMB Personal Computer Guide" I used the commands :

SCRATCH D0, "TESTFILE"

I also tried the BASIC 2.0 commands

OPEN 15,8,15
PRINT#15, "S0:TESTFILE"
CLOSE 15

There were no errors and I was returned to the READY so it suggested something had happened but the file was still on the microSD card.

Tez
 
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dave_m

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I can't seem to scratch files.

Tez,
Only the SAVE and LOAD functions were advertized so, while I did try some BASIC 4 commands for fun, I never thought to try to erase a file from the PET (good for you for trying). There is of course no problem in erasing a file on the SD card from the PC.

I wonder what would happen if you SAVED a file from the PET with a file name that already existed on the SD card? Would it overwrite or would it create a second file? I cannot remember what a 4040 drive does. I think it creates another file.
-Dave
 
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tezza

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There is of course no problem in erasing a file on the SD card from the PC.

Indeed. I was just playing around to see how much disk functionality had been enabled. Given that PET disk drives are as rare as hen's teeth in NZ, I'm thrilled to see Mike (Gubbish) put this together, support it and make it available at such a low cost. I wish all my old micros had similar devices! (although some have, actually).

Tez
 

dave_m

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I wonder what would happen if you SAVED a file from the PET with a file name that already existed on the SD card? Would it overwrite or would it create a second file? I cannot remember what a 4040 drive does. I think it creates another file.
-Dave

I tried it on both and they act the same. They overwrite the file.
 

for()

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I wonder what would happen if you SAVED a file from the PET with a file name that already existed on the SD card? Would it overwrite or would it create a second file? I cannot remember what a 4040 drive does. I think it creates another file.
I tried a SAVE"TEST",8 on my 4040 followed by another SAVE"TEST",8 and it gave me a 63, FILE EXISTS as I expected.

If you want to overwrite it, SAVE"@:TEST",8 works.
 

dave_m

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I tried a SAVE"TEST",8 on my 4040 followed by another SAVE"TEST",8 and it gave me a 63, FILE EXISTS as I expected.

That's more to what I recall should happen. I will have to repeat my tests.

If you want to overwrite it, SAVE"@:TEST",8 works.

I think the "@" only works with the BASIC 4 DSAVE command or utilities like DOS Support or BATPRO.
 

for()

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I think the "@" only works with the BASIC 4 DSAVE command or utilities like DOS Support or BATPRO.
It doesn't depend on the BASIC version. It's just standard Commodore DOS running inside the floppy. Have a look at the manual, if you don't believe me ;-)
 

bitfixer

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Indeed. I was just playing around to see how much disk functionality had been enabled. Given that PET disk drives are as rare as hen's teeth in NZ, I'm thrilled to see Mike (Gubbish) put this together, support it and make it available at such a low cost. I wish all my old micros had similar devices! (although some have, actually).

Tez
Thanks Tez, glad I could help bring some fun to the hobby.
The current firmware only does load, save, and load "$", so no support for scratching/deleting files... yet. Adding it to the list, it seems like a simple feature to implement.
 

bitfixer

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Same here, I'm afraid; I can load programs (and the directory) without problems but save "HELLO",9 (or 8 ) only goes through the motions (i.e. a respectable pause, no error) but nothing gets saved, alas (8032, BASIC 4). Locking/unlocking doesn't seem to make any difference.

If you get a chance when you meet with Steve, I would try swapping SD cards with his PETdisk to see if saving works. I believe Steve's petdisk was saving properly? If there is a difference in behavior between the two units, then there may be an issue with your hardware, in which case I would be happy to send you a replacement. I could include it when I send the upgraded MCU chips next week.
 

bitfixer

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Nearly finished with the firmware update..
Just got wildcards working in the main PETdisk firmware, and the SD bootloader is also functional. The ATMega8 chip does not have enough memory for both the bootloader and the main code, so I'm waiting for some ATMega168s to arrive so I can put both of those on there and check everything out.
In the meantime, if anyone is looking for something to play with, I've posted the new firmware with wildcard support at
http://bitfixer.com/bf/data/PETDisk_v2.hex

If you happen to have an AVR programmer you can flash that onto the chip and play around with it. This will be a subset of the features that will be included when I send out the chip upgrades to everyone.
Thanks and hope everyone had a good weekend.
- Mike
 

MikeS

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It doesn't depend on the BASIC version. It's just standard Commodore DOS running inside the floppy. Have a look at the manual, if you don't believe me ;-)
ISTR that SAVE @ was the subject of much discussion back in the day because apparently there was an elusive bug in the 1541 drive that could cause disk corruption when the stars and the moon were in a particular configuration (although there was a cult of die-hard deniers) ;-)
 

MikeS

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If you happen to have an AVR programmer you can flash that onto the chip and play around with it. This will be a subset of the features that will be included when I send out the chip upgrades to everyone.
- Mike
Did you ever get that simple interface working with a 'real' RS-232 port, and if so, how did you connect to the PETdisk?
 

bitfixer

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I did eventually get it working -
I build that circuit as described and put individual wires for the 4 signals - RST, MOSI, MISO, and CLK.
In order to connect to the chip I did need to remove it from the circuit and program it on a breadboard, providing power from a separate supply.
On the Atmega8, the pins you need to connect are:
RST - pin 1
+5v - pin 7
Gnd - pin 8
MOSI - pin 17
MISO - pin 18
SCK - pin 19

I attempted to do this by connecting in-circuit to the PETdisk, but was not successful. I believe the zener diodes connected to MOSI and SCK on the PETdisk circuit were causing trouble with the programming, but if you modify the DASA circuit to remove the zeners from those signals on that side, it might work. I didn't try this. It was simpler to just move the chip to a breadboard and program it there.

and on the computer side I used a program called AVRDUDE to connect to the chip and upload the hex file.
I would be happy to provide more info and the exact command line options if you want to try this out.
New chips should be arriving today, I hope!
 

bitfixer

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PETdisk on Retrocomputing Roundtable! and firmware upgrade..

PETdisk on Retrocomputing Roundtable! and firmware upgrade..

Hello again,

Wanted to share some news with everyone,
The PETdisk got a mention in the latest installment (show 16) of the Retrocomputing Roundtable podcast! David Greelish had a PETdisk with him at last weekend's ECCC Commodore expo in Chicago, and he talked a bit about the PETdisk as well as giving one away as a prize at the show. I am a fan of this podcast so it was a thrill to hear them mention it!

And about the upcoming PETdisk firmware upgrade:

I've sent messages to current PETdisk owners about the firmware upgrade, which includes:
- SD card bootloader
- Wildcard support
- DLOAD command
- bug fixes

If anyone did not receive a message (either email or PM) then I apologize, please send me a message and I will get you the upgrade information.
Last night I ironed out the last few bits with the bootloader - want to be extra careful on that part, since it will be a part of the code which cannot be modified easily. A little bit of a squeeze getting the SD card routines, plus just enough FAT support to find and read the firmware file into a 2k bootloader, but it does just fit. There will be 14k of program memory on the rest of the chip to support the full PETdisk firmware, which should be enough space to comfortably fit the current feature set and future expansions.
I'm planning to send these out free of charge to everyone, the chips are not very expensive and postage will be at the normal letter rate (cheap). I just want to make sure everyone gets the latest stuff. Some people have offered to kick in for postage/chip cost, which I certainly welcome but which is definitely not required. Your bug reports, encouragement, and appreciation are more than enough.
And of course all PETdisks sent out from now on will have the update.

I will continue to nail down the firmware coding, and will try to wrap up tonight or tomorrow. Aiming to send out the chips Friday or Saturday. Thanks again for your patience and happy PETdisk'ing.
 
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