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Old 3rd May 2021, 6:59 pm   #12
ortek_service
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Default Re: Raspberry Pi as a storage device for a PET.

Quote:
Originally Posted by SiriusHardware View Post
Reading through the project details it seems to me that the originator has done a lot of testing, or a lot of testing has been done for him by friendly PET owners on a number of different PETs - my angle would tend to be that if it isn't broken, don't fix it. Just try it the way it is.
Yes, I presume people got this to work, but it maybe a bit marginal / may be putting > 3.3V into the RPi. And the PNP transistor doesn't really seem to be needed, as the 10k resistor in-series with +5V to it will be the limiting factor.
So might just as well had a standard resistor-pullup common-emitter NPN Inverter / level-converter , as used on the 5V to 3.3V opposite-direction write-line

Quote:
Originally Posted by SiriusHardware View Post
The only thing I could wish for is, if you were going to connect something as complex and powerful as a Pi, it might as well be emulating the FDD (ie, functionally equivalent to the SD2PET) rather than the datasette as that would seem like a better way to use one.

The Pi would then have to be interfaced to the IEEE 488 port, and that would present its own complications. It might be worth looking around to see if someone has already done it.
Co-incidentally, I'd said exactly this a few posts before!

With the Arduino-ATMegea 328 based Tapuino the most common Datasette Solid-state replacement. Although it seems this RPi one has ways of increasing the data speeds, that might not be in the Tapuino as standard.


A Solid-state Disc drive replacement would be more flexible, and should be able to do something like the Pi1541 for the PET (Which having the full IEEE Parallel interface rather than Commodore's bodged cut-down Serial-IEEE, should also be much faster as standard).

But I hadn't noticed anyone doing one yet for the PET - Maybe as they aren't as common as the (World's best selling Home Computer - around 30 million sold) C64 etc. And maybe the SD2PET has now become the one everyone uses
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