Random hardware ideas!

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Silvester
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Re: Random hardware ideas!

Post by Silvester »

Re TK2 and RTC on ROMport

Best to forget using MM58274C, the SGC/GC uses a triple lock to prevent corruption (write to 3 addresses each and every time you need to write to a register). Whereas DS1374C uses I2C link, with bonus of integrated crystal and charger, making it much simpler. Downside, only appears to be available from recognised suppliers (for the price of P/P I could buy several MM58724C off ebay).

Like to knock up prototype and play with I2C bit banging / EPROM paging scheme. Assembler though, none of this C nonsense :-).

Next would be writing Net handler for AVR (assembler). Cheap UNO/Mega with Ethernet+SD shield allows hacking access to W5100 (nothing ambituous in terms of speed, perhaps just tinkering over OPEN#3;'N1_ETH0').

Access to Arduino SD library would be limited to 8.3 filenames (FAT 16/32), so perhaps something like mini QXL file for MDV (similar to Carlos Delhez's *.MDR scheme for ZX)


David
Silvester
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Re: Random hardware ideas!

Post by Silvester »

Derek_Stewart wrote:The addition of a SA0199 sounds interesting, do you have any details or photographs.
It was DIY, added with a lot of other things. The SAA1099 actually has DTACK output so is easy to interface directly. Mine was on 6800 bus E/VPAL (6522, 6850 etc)


David
Martin_Head
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Re: Random hardware ideas!

Post by Martin_Head »

I was thinking. If you used something like a Raspberry PI to connect to a BBQL network, to read and write network packets. Mimicking a real QL.

You could then run a router program on the Raspberry PI, and connect it to my IPNet driver on a PC via the Ethernet connection on the PI. Getting a QL to network with QPC2.


martyn_hill
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Re: Random hardware ideas!

Post by martyn_hill »

Hi Martin

In fact, that is a very similar idea to what I am developing - but using a uC dev board (similar to the Genuino/Arduino, but with more memory and 'native' USB - the 'Teensy ++2.0').

The idea being to connect my BBQL(s) to QPC via USB and this QNet-USB adapter.

I have been wondering how it might interact with your IPNet drivers as well... I plan to replace the physical Net code from the TKII source on QPC/SMSQEwith a simplified 'message-bus' client/server, which sends and receives the packets down the (virtual) Serial port... That part obviously would overlap with how you appear to have developed the IPNet driver (I took a look at your source code when you released it!)

Still got a little way to go re-factoring the physical QNet driver in C for the Atmel uC - a couple of weeks away before I can prove the concept, but simple messages are passing back and forth reliably between QPC and the adapter/uC so far.

Still, nice to have the concept vindicated by others!


Derek_Stewart
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Re: Random hardware ideas!

Post by Derek_Stewart »

Hi,

I am going to setup my old BBS and connect it via a Null modem connection to a Raspberry PI, to allow possible connection from the Internet.

I am not sure about what platform, a Q40 has 4 serial ports so 4 lines available.


Regards,

Derek
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Peter
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Re: Random hardware ideas!

Post by Peter »

Silvester wrote:Whereas DS1374C uses I2C link, with bonus of integrated crystal and charger, making it much simpler. Downside, only appears to be available from recognised suppliers (for the price of P/P I could buy several MM58724C off ebay).
There is a cheaper version for external crystal, the DS1374U.


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Cristian
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Re: Random hardware ideas!

Post by Cristian »

tcat wrote:Hi,
3D printed QL-matching case
https://www.dropbox.com/s/0le6rd2a3mnm8ur/QL_8.jpg?dl=0


Timbucus
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Re: Random hardware ideas!

Post by Timbucus »

@christian - like the picture - mine looks very similar at the mo with an SD card IDE in an old MD case on the left and two Spectrum Md's on the right....

The PI connected to the cartridge port was one I have been musing in the wrong threads - sorry guys... if you see the work that the BBC tube people http://stardot.org.uk/forums/viewtopic.php?t=11325 are doing it is possible to get a PI to act with only a 5v-3v buffer chips direct to the Add/Data lines - although that is only at 2MHz and they are struggling there so I assume if the Cart port may be handling data at 7MHz like the rest of the system the idea is dead in the water except perhaps for some form of software rate limited IO pipeline - which still may be OK for many purposes. The ZX Next has a bare metal PI hooked to the board as a co-pro but, as I have not seen the design it may have logic in the onboard FPGA for interfacing.

So I am coming to the opinion that perhaps a small hardware unit to handle the IO is the best approach - views?

Tim


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Dave
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Re: Random hardware ideas!

Post by Dave »

Christian, no! Just no! Obviously that QL has crashed, because all the microdrives are on at once!

I think 2 extra is a reasonable limit. Don't you?


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Dave
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Re: Random hardware ideas!

Post by Dave »

Silvester wrote:Best to forget using MM58274C, the SGC/GC uses a triple lock to prevent corruption (write to 3 addresses each and every time you need to write to a register). Whereas DS1374C uses I2C link, with bonus of integrated crystal and charger, making it much simpler. Downside, only appears to be available from recognised suppliers (for the price of P/P I could buy several MM58724C off ebay).
I am looking seriously at this. If anyone wants to throw a schematic and maybe some example code out there, there's a very high probability it will get included. I'd need an address to put it at that wouldn't conflict with anything else, too. Has anyone else already used this on a QL?

I have shopped around and found some for $3.50.


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