Random hardware ideas!

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tofro
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Re: Random hardware ideas!

Postby tofro » Thu Apr 27, 2017 8:20 pm

Maybe I misunderstood - i was assuming an 680>=20 CPU. Hard to keep up with the complete discussion. A 68008 would most probably have a hard time feeding the DAC continuously.

Tobias


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Peter
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Re: Random hardware ideas!

Postby Peter » Thu Apr 27, 2017 8:52 pm

From Dave not adding Flash, in order to do that on the "Super Duper Gold Card", I concluded the recently discussed card was not the "Super Duper Gold Card".
And I was assuming the 680>=20 CPU card and the "Super Duper Gold Card" mean roughly the same.

Both might be wrong. :D


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Re: Random hardware ideas!

Postby Dave » Thu Apr 27, 2017 10:15 pm

Peter wrote:
Dave wrote:
Peter wrote:Will (Flash) EPROM be there?

No. I'll have to save working on that for the Super Duper Gold Card*

But that would make the card dependant on loading the SDHC drivers from microdrive!
Or dependant on a second extension card for mass storage with feed-through QL bus.

I would at least add a cheap little PLCC32 64KB OTP EPROM. Otherwise this could become a disaster.

Such a little EPROM, however, could make large Flash redundant, if you add the option to switch its area to RAM. It could contain a loader and read the OS from SDHC. And if writing a loader gets too hard, it could at least contain the SDHC driver.


I misunderstood you. Yes, it will have an EPROM for the driver. It won't have the 2MB of flash I plan to put on the SDGC.


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Re: Random hardware ideas!

Postby Dave » Thu Apr 27, 2017 10:21 pm

Peter wrote:From Dave not adding Flash, in order to do that on the "Super Duper Gold Card", I concluded the recently discussed card was not the "Super Duper Gold Card".
And I was assuming the 680>=20 CPU card and the "Super Duper Gold Card" mean roughly the same.

Both might be wrong. :D


My main project is a 68EC020 card with 12MB SRAM and 2MB flash. It will have a through connector.

My secondary project which will be done first is a little ethernet/QL-SD/RAM card that may also have USB, battery backed clock, PS/2, whatever I can get schematics for to include. That card will have a 64k ROM carrying Minerva and the new Alain Haoui QL-SD/QubIDE driver. If things go well, it MIGHT get a 68SEC000 just for the extra address lines and lots of RAM in a later revision - but only if it makes sense and doesn't conflict with doing the SDGC.


Silvester
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Re: Random hardware ideas!

Postby Silvester » Sat Apr 29, 2017 9:24 am

More random thoughts (I think you may have opened a Pandora's box Dave):

Could do with a prototyping PCB for ROM port, if enough are produced it could help with cheap DIY projects (soundchip, etc). Maybe with a fixed PAL to provide simple I/O facility to prototyping area (ie. using address lines for Write). So hopefully, if the worst happens, only the PAL is fried. Anyone had any experience with suitable PCBs (required thickness/reliable slot tracks) from suppliers (China?).

The simple ABS box (100x75x40mm), as used by Miracle for ROM port MIDI interface, has proved reliable. If slot for PCB is cut in right place it sits neatly and flat on back of QL (no ZX81 RAM pack wobble!). Would allow 90x70mm prototyping area. Could also neatly fit 16x2 LCD display (etc) in lid of box.

I've got a few ATmega328's (28 pin DIL) that would be interesting to interface to QL likewise. Hmm, reliable fast buffered SER?, USB/PS2 mouse/keyboard?. AFAIK sketches for USB/PS2 already exist.


Silvester
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Re: Random hardware ideas!

Postby Silvester » Sat Apr 29, 2017 9:33 am

Peter wrote:
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.

The version without crystal is uSOP sized, I'm OK with soldering SOP but never tried uSOP.

Found a better price for DS1374C than £9.99+£6.99 p/p!

RS components do them for £5.52 C (£2.82 U) free p/p.
Last edited by Silvester on Sat Apr 29, 2017 9:43 am, edited 1 time in total.


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tofro
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Re: Random hardware ideas!

Postby tofro » Sat Apr 29, 2017 9:40 am

Silvester wrote:
Could do with a prototyping PCB for ROM port, if enough are produced it could help with cheap DIY projects (soundchip, etc). Maybe with a fixed PAL to provide simple I/O facility to prototyping area (ie. using address lines for Write). So hopefully, if the worst happens, only the PAL is fried. Anyone had any experience with suitable PCBs (required thickness/reliable slot tracks) from suppliers (China?).

The simple ABS box (100x75x40mm), as used by Miracle for ROM port MIDI interface, has proved reliable. If slot for PCB is cut in right place it sits neatly and flat on back of QL (no ZX81 RAM pack wobble!). Would allow 90x70mm prototyping area. Could also neatly fit 16x2 LCD display (etc) in lid of box.

I've got a few ATmega328's (28 pin DIL) that would be interesting to interface to QL likewise. Hmm, reliable fast buffered SER?, USB/PS2 mouse/keyboard?. AFAIK sketches for USB/PS2 already exist.


QLSD is nearly what you're looking for: It has an SPI port with at least 1 free select line you could use to chat with your AVRs.

Tobias


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Re: Random hardware ideas!

Postby Dave » Sat Apr 29, 2017 3:23 pm

Silvester wrote:More random thoughts (I think you may have opened a Pandora's box Dave):

Could do with a prototyping PCB for ROM port, if enough are produced it could help with cheap DIY projects (soundchip, etc). Maybe with a fixed PAL to provide simple I/O facility to prototyping area (ie. using address lines for Write). So hopefully, if the worst happens, only the PAL is fried. Anyone had any experience with suitable PCBs (required thickness/reliable slot tracks) from suppliers (China?).

The simple ABS box (100x75x40mm), as used by Miracle for ROM port MIDI interface, has proved reliable. If slot for PCB is cut in right place it sits neatly and flat on back of QL (no ZX81 RAM pack wobble!). Would allow 90x70mm prototyping area. Could also neatly fit 16x2 LCD display (etc) in lid of box.

I've got a few ATmega328's (28 pin DIL) that would be interesting to interface to QL likewise. Hmm, reliable fast buffered SER?, USB/PS2 mouse/keyboard?. AFAIK sketches for USB/PS2 already exist.


I do have an old prototyping PCB from the 80s here that is a regular expansion card. It contains a 5v regulator and fusible link, a PAL that decodes a 16k block, four or six 24-pin or 28-pin S_DIP locations with thru-holes nearby for wire-wrapping, and rest of the board is solderable bread board. It looks a bit like this: http://www.rwapadventures.com/ql_wiki/i ... e=Hardware but with the basics in place.

If I were to do something like that, it would be a regular expansion card for prototyping then a J1->ROM port adapter card bringing through just the relevant lines. That way you could use it in the rom port with a good work area or in the expansion port if you needed to access more signals or manipulate the CPU, or both.

I would also alter it so that it had a few SMD pad areas for convenience.


Timbucus
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Re: Random hardware ideas!

Postby Timbucus » Sun Apr 30, 2017 1:18 pm

Dave,

Put me down for one - I have no space on my expansion port as I have Zaxxon's card but, the ROM port adapter was what I was looking for to hook up my rPI and other projects. Would you plan to build something in to assist with the latching of writes from an unused address area as it is read only?

Timbucus


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Re: Random hardware ideas!

Postby Dave » Sun Apr 30, 2017 1:46 pm

Well, what about the smallest QL backplane? Simply a 1->2 connector backplane that fits internal to the QL and lets you put your QubIDE card directly above another card? I made one of these for my own personal use. I then put an insulating layer under the top card and applied some vinyl to the metal keyboard backplate to prevent shorts. If I had it to do over I would just 3D print rails on either side that attach to the backplane to guide cards in nicely, plus a small 20mm card extender sleeve.



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