Hi Everyone,

I've just found some old parts from my original Commodore 64 days, and among them was a cartridge board with a 2716 EPROM fitted. It was the firmware for a C64-based EPROM programmer (bare PCB) and, out of curiosity, I dumped the contents.

it seems the programmer was a "Zero S.C ...

Hello,

I'm working on a work-alike build of an Acorn System 1 , which had an NMOS 6502 running at 1MHz. I've got a fistfull of Rockwell 6502s to hand, but the 1MHz crystal was a bit more bother. It seems they only exist in the big HC-51 package, which is too big for my board, so I'm planning on ...

Regrettably the programming algorithm is very different and the TL866 doesn't support them, so I need Lattice ones.

I've just checked 10 from an eBay supplier I've used for SRAM in the past with no problems - and only 1 out of 10 programmed & verified and is now in use.

How's UTSource for GALs - any recent experiences?

Any other reliable, named sources (I'm in the UK).

Thanks.

Edit: Supplier was chips-fans. 8 ...

> Might get some info from the Stardot readership

Thanks.

I registered there in July 2015 but no-one activated my account! I've just registered again.

I see the post over there is getting a bit of general feedback, but nothing specific about numbers of units. I know there's one at The Centre ...

Someone's just bought the top half (keyboard, display and cassette interface) of an Acorn System 1 for an astounding £511:

http://www.ebay.co.uk/itm/162185542432?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

When I saw the listing appear, I stuck in a max bid of £15 thinking it would ...

It turned out that the prototyping Eurocards I obtained aren't suitable for small (non 24/40-pin) DIP chips so I have decided to lay out some boards and I am currently entering the original Acorn schematics into KiCad. The aim is to have single sided versions of the originals so that they can be ...

SHE LIVES!!!

20150710_202409-small.jpg
Previous rework removed and the cut tracks repaired - pic below.
Three broken wires on the display Spectrastrip repaired - one was a hairline break that I only found out when I powered up for the first time and noticed a display digit wasn't working ...

As well as the overall restore, I am debating whether to repair or replace the spectrastrip to the display (quick and easy) or replace it (minor hassle, but where to get a small bit?).
If you are okay with not having actual spectrastrip just take an old 40 pin IDE cable and make a "donor" out of ...

Sure will - having the real thing is a great bonus. I just need to find some time to make a start and sort out how to do the keyboard.

...but the big question is: Do I get it going 'as is', or repair the cut tracks and fit the address select header as per the design spec.
If it were me, I'd attempt to restore it to the original circuitry.

Do you know which chips are missing?

Yes, I have all the schematics and the tech/user ...

A chance comment I made to an article over at Hacker News led to me being offered a non-working Acorn System 1 for spares or repair for the cost of a donation to charity. Well, it arrived yesterday and it's in pretty good shape. The main board has some logic chips missing and the memory addressing ...

"A public appeal for people who can repair BBC Micro computers has been launched by a museum.
The National Museum of Computing (TNMOC) needs help to maintain the stock of BBC machines it uses in education programmes and exhibits.

It is looking for people familiar with the computer and its ...

Hi Linker3000,

Which 74xx/74LSxx parts are you having trouble sourcing? Perhaps your stateside associate could help you with these, too?

Regards, Mike


CPU Board Jameco Mouser
------------- ------ ------
IC9 74LS20 0.79 1.00
IC10 74LS139 0.69 0.86
IC11 74LS04 0.49 0.74
IC12 74LS00 0.45 1.20 ...

Well, as you might have guessed by now, this project is not exactly a rush job!

Best laid plans and all that - my trip to the USA was postponed so I have two 1MHz crystals sitting in San Jose that I won't be able to pick up until around September. Never mind, I bought a tray of 24 off a well-known ...