27C400/27C800 EPROM emulator

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cmorley
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Joined: Tue May 28, 2019 5:46 pm

Re: 27C400/27C800 EPROM emulator

Post by cmorley » Wed Jan 08, 2020 6:47 am

Tidy up continuing - just buttoning up a few things. It seems newlib-nano doesn't really live up to its name. I binned off the ctype library functions and saved 800 bytes of unnecessary c-locale information. On a 32K FLASH MCU that is huge.

95% of the strings are now refactored into the string table now so translation would be pretty easy... I might add the option because unless the FLASH erase & program library busts my .text section limit it is a 4 line function (flash unlock, flash erase, flash program, flash lock).

Squirrel61
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Joined: Wed Dec 18, 2019 5:22 pm

Re: 27C400/27C800 EPROM emulator

Post by Squirrel61 » Wed Jan 08, 2020 8:38 pm

Thanks again for all the work you're putting in this! I can't wait until you start distributing them!

cmorley
Posts: 142
Joined: Tue May 28, 2019 5:46 pm

Re: 27C400/27C800 EPROM emulator

Post by cmorley » Sat Jan 11, 2020 2:56 pm

Programming the language from the menu doesn't fit in the MCU's code FLASH. It is a couple hundred bytes over. :(

A translation built from source would still be possible but probably not worth the effort. I have just corrected all the compiler warnings so it build warning free now. I'll package up the new firmware and send it to the testers.

I also built up ten of the modules from the new batch of PCBs. I am just waiting on some 1uF 0402 caps from Mouser to finish these off (Mon/Tue)... they work without the caps and the noise on the rail is within spec for the chips but it is smoother with them. The regulator doesn't need them for stability.

I'm thinking £20 for the issue D "beta" units. The final release issue 1 might be more or might be cheaper - it depends on the economy of scale I can achieve and yield from the assembly house. For now issue D are all hand assembled by me :?

reinauer
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Joined: Sun Jan 12, 2020 6:56 pm

Re: 27C400/27C800 EPROM emulator

Post by reinauer » Sun Jan 12, 2020 8:22 pm

Will they fit in an A4000D? If so I would like to order 2 of the latest batch if still available.

cmorley
Posts: 142
Joined: Tue May 28, 2019 5:46 pm

Re: 27C400/27C800 EPROM emulator

Post by cmorley » Sun Jan 12, 2020 10:51 pm

reinauer wrote:
Sun Jan 12, 2020 8:22 pm
Will they fit in an A4000D? If so I would like to order 2 of the latest batch if still available.
I think the A4000 has the same ROM pinout as the A1200. Google says 27C400 for A4000 - if so then yes they should work. There will be plenty to go around I can easily order more parts and assemble a few more.

cmorley
Posts: 142
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Re: 27C400/27C800 EPROM emulator

Post by cmorley » Mon Jan 13, 2020 12:20 pm

No capacitors today. Fedex website claims I wasn't in which is BS. No delivery attempt & no card. :x

edit: They did turn up at 2pm on a before 12 service. So log it on the system as undelivered at 10:39am then deliver it at 2pm... is that better or worse than a few years ago when they were logging as delivered before noon then throwing the parcel at me at 2pm? :|

cmorley
Posts: 142
Joined: Tue May 28, 2019 5:46 pm

Re: 27C400/27C800 EPROM emulator

Post by cmorley » Tue Jan 14, 2020 12:37 pm

Booting diagrom on an A1200:
Photo0892.jpg
Photo0892.jpg (115.82 KiB) Viewed 1499 times
Switching between Diagrom 1.2 and KS3.1.4 working on the A1200. I don't have a spare A1200 keyboard so triggered the ROM switch from the USB.

I might make the boards a fraction narrower in issue 1 for side to side. These issue C fit like a glove because they were individually milled out - the issue D are V-groove so might need a quick swipe on sandpaper (or don't snap them apart!).

I will make a thread in the GENERAL->PC SALES (as they aren't Atari sales) to take names for beta units.

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rubber_jonnie
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Re: 27C400/27C800 EPROM emulator

Post by rubber_jonnie » Tue Jan 14, 2020 3:27 pm

cmorley wrote:
Mon Jan 13, 2020 12:20 pm
No capacitors today. Fedex website claims I wasn't in which is BS. No delivery attempt & no card. :x

edit: They did turn up at 2pm on a before 12 service. So log it on the system as undelivered at 10:39am then deliver it at 2pm... is that better or worse than a few years ago when they were logging as delivered before noon then throwing the parcel at me at 2pm? :|
Don't get me started on couriers. On Monday they left £150s worth of air tank on my front doorstep for all the world to see. I was working from home all day, saw a DPD van arrive, and got no ring or card, so assumed it was for somebody else.

My wife found it when she got home from work at 16:00.

On another note, I am up for testing these if you're still in need.
Collector of old Atari things:
800XL + Ultimate 1MB, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k +APE Warp) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg), 1040STF long button floppy, 2x 1040 STFMs + Gotek, 2x 4160STE with 32Mhz booster, ROM switcher, Mega ST1, Mega ST4, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

nikoskon
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Re: 27C400/27C800 EPROM emulator

Post by nikoskon » Tue Jan 14, 2020 9:31 pm

Great little project there :o
Will definitely be in for a few of these when available, 2 for A1200 and 1 for the others (A500, A600, and A2000) :D

Squirrel61
Posts: 15
Joined: Wed Dec 18, 2019 5:22 pm

Re: 27C400/27C800 EPROM emulator

Post by Squirrel61 » Sat Jan 18, 2020 11:32 am

I'm in for 1 or 2 too. I guess the PC SALES topic hasn't been opened yet, because I couldn't find it. Maybe you can link it here as soon as you open it?

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