6502.org Forum Projects Code Documents Tools Forum
It is currently Sat Nov 23, 2024 3:00 pm

View unanswered posts | View active topics


Board index » 6502.org Users Forum » Newbies

All times are UTC




Post new topic Reply to topic  Page 3 of 4
  [ 60 posts ]  Go to page Previous  1, 2, 3, 4  Next
  Previous topic | Next topic 
Author Message
BigDumbDinosaur
 Post subject: Re: shopping list
PostPosted: Mon Apr 03, 2023 12:37 am 
Offline
User avatar

Joined: Thu May 28, 2009 9:46 pm
Posts: 8509
Location: Midwestern USA
GARTHWILSON wrote:
In ye olden days, the Φ2 output always went to the other things that took Φ2...

That was back when clock generators were too weak in the knees to run more than one or two TTL loads. Clock generators have greatly improved, and in modern systems, everything is CMOS.

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!
Top
 Profile  
Reply with quote  
BigDumbDinosaur
 Post subject: Re: shopping list
PostPosted: Mon Apr 03, 2023 12:38 am 
Offline
User avatar

Joined: Thu May 28, 2009 9:46 pm
Posts: 8509
Location: Midwestern USA
allisonlastname wrote:
This better?

Yep! You’ve got the resistor in the right place.

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!
Top
 Profile  
Reply with quote  
barnacle
 Post subject: Re: shopping list
PostPosted: Mon Apr 03, 2023 5:03 am 
Offline

Joined: Mon Jan 19, 2004 12:49 pm
Posts: 986
Location: Potsdam, DE
allisonlastname wrote:
All the 74 is supposed to be 74HC but kicad only has 74LS symbols for a lot of stuff.


Double click on the part name on the schematic to change it, once you've selected the logic symbol. Your BOM will be correct then, too.

Neil
Top
 Profile  
Reply with quote  
allisonlastname
 Post subject: Re: shopping list
PostPosted: Wed Apr 05, 2023 10:31 pm 
Offline
User avatar

Joined: Mon Mar 06, 2023 9:26 am
Posts: 88
Location: UK
I've run into an issue. Mouser don't have any 28c256, 28c64 or 28c010 chips in stock, and they won't have any until mid-july.

What can I use instead of those?

_________________
probably the youngest person on this forum
Top
 Profile  
Reply with quote  
Sean
 Post subject: Re: shopping list
PostPosted: Wed Apr 05, 2023 10:50 pm 
Offline

Joined: Mon Feb 15, 2021 2:11 am
Posts: 100
allisonlastname wrote:
I've run into an issue. Mouser don't have any 28c256, 28c64 or 28c010 chips in stock, and they won't have any until mid-july.

What can I use instead of those?


Jameco still has the 28c256 in stock:
https://www.jameco.com/z/28C256-25-Majo ... 74878.html
Top
 Profile  
Reply with quote  
floobydust
 Post subject: Re: shopping list
PostPosted: Wed Apr 05, 2023 10:51 pm 
Offline
User avatar

Joined: Tue Mar 05, 2013 4:31 am
Posts: 1385
allisonlastname wrote:
I've run into an issue. Mouser don't have any 28c256, 28c64 or 28c010 chips in stock, and they won't have any until mid-july.

What can I use instead of those?


How soon are you looking to obtain parts? I'm going to start selling off my 5-volt inventory of parts... much stuff, including AT28C256 in 28-pin DIP and 32-pin PLCC, AT28V64 in DIP... lots of 74HC/HCT logic chips and the list goes on.... note that I'm moving over to SMT and 3.3-volt stuff... and away from pin-in-hole designs.

_________________
Regards, KM
https://github.com/floobydust
Top
 Profile  
Reply with quote  
allisonlastname
 Post subject: Re: shopping list
PostPosted: Wed Apr 05, 2023 10:58 pm 
Offline
User avatar

Joined: Mon Mar 06, 2023 9:26 am
Posts: 88
Location: UK
Sean wrote:
Jameco still has the 28c256 in stock:


Ordering from Jameco would appear to mean transatlantic shipping, which is generally undesirable, not least for reasons of time.

floobydust wrote:
How soon are you looking to obtain parts?


Pretty soon. See note above about transatlantic shipping.

I did notice that someone else earlier in the thread suggested a 39SF010, which I'm not entirely sure about due to it being flash and not EEPROM. My thought is that it might be harder to program, but I could be completely wrong.

_________________
probably the youngest person on this forum
Top
 Profile  
Reply with quote  
floobydust
 Post subject: Re: shopping list
PostPosted: Wed Apr 05, 2023 11:14 pm 
Offline
User avatar

Joined: Tue Mar 05, 2013 4:31 am
Posts: 1385
Not sure of your location.... so shipping would be what it is.... as I'm based in South Florida.

The flash devices have a different programming structure. My Monitor code can program the AT28C256 insitu for single/multiple bytes. The flash devices are sector based... from the datasheet, you need an unlock sequence first, then an erase of a 4KB sector, followed by programming the sector with the new data. Certainly different, but shouldn't be a problem. One thing to note however... the unlock sequence is done by sending specific byte patterns to specific addresses first. The spread on those addresses is around 24KB or so... so if you're not accessing that much of the chip, programming it insitu is not an option. I found the same issue with the Atmel AT28BC256 (battery voltage 3.3v EEPROM). I changed the memory addressing so only 8KB of EEPROM is accessed and I can't use my Monitor code to change it... drats!

_________________
Regards, KM
https://github.com/floobydust
Top
 Profile  
Reply with quote  
drogon
 Post subject: Re: shopping list
PostPosted: Thu Apr 06, 2023 6:59 am 
Offline
User avatar

Joined: Wed Feb 14, 2018 2:33 pm
Posts: 1488
Location: Scotland
allisonlastname wrote:
Sean wrote:
Jameco still has the 28c256 in stock:


Ordering from Jameco would appear to mean transatlantic shipping, which is generally undesirable, not least for reasons of time.


Mouser has it in the UK (which is where I think you are)

https://www.mouser.co.uk/ProductDetail/ ... grbg%3D%3D

However at that price, I suspect an alternative would be better.

Quote:

Pretty soon. See note above about transatlantic shipping.



The issue for us in the UK right now is not just time, but import duty, VAT and local postage. It can double the cost of some things if not careful.

-Gordon

_________________
--
Gordon Henderson.
See my Ruby 6502 and 65816 SBC projects here: https://projects.drogon.net/ruby/
Top
 Profile  
Reply with quote  
BigDumbDinosaur
 Post subject: Re: shopping list
PostPosted: Thu Apr 06, 2023 4:12 pm 
Offline
User avatar

Joined: Thu May 28, 2009 9:46 pm
Posts: 8509
Location: Midwestern USA
Sean wrote:
Jameco still has the 28c256 in stock:
https://www.jameco.com/z/28C256-25-Majo ... 74878.html

That is a very slow part, 200ns.

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!
Top
 Profile  
Reply with quote  
Paganini
 Post subject: Re: shopping list
PostPosted: Thu Apr 06, 2023 4:37 pm 
Offline

Joined: Fri Mar 18, 2022 6:33 pm
Posts: 491
UTSOURCE has fast ones for ~$5.

https://www.utsource.net/itm/p/6175055.html

They are pulls, but I bought some and they seem to be high quality.

_________________
"The key is not to let the hardware sense any fear." - Radical Brad
Top
 Profile  
Reply with quote  
No True Scotsman
 Post subject: Re: shopping list
PostPosted: Wed Aug 16, 2023 9:20 pm 
Offline

Joined: Wed Mar 22, 2023 3:58 am
Posts: 37
Location: teh interwebz
allisonlastname wrote:
I'm planning to build it on a breadboard to save having to design a PCB or learn wire wrap....

Have you considered these stripboards that have the traces laid out like a breadboard?

https://www.ebay.com/itm/114721914362

They come in various sizes. This is just the example that came to hand the quickest. Some are big enough for several rows of ICs. I like the ones like this one where the ICs straddle both power rails. It makes it easy to connect VCC and ground, and place a capacitor near each chip.
Top
 Profile  
Reply with quote  
No True Scotsman
 Post subject: Re: shopping list
PostPosted: Wed Aug 16, 2023 9:35 pm 
Offline

Joined: Wed Mar 22, 2023 3:58 am
Posts: 37
Location: teh interwebz
No True Scotsman wrote:
They come in various sizes.

Here's one with two rows.

https://www.ebay.com/itm/115271688771

The "5er" in the description refers to the fact that there are 5 pinholes at each connection point. You'll want to base your purchase on how many jumper wires will be connected to each IC pin. Bear in mind that wide DIPs will obscure some of the holes, but you can usually snake a couple of 22 AWG wires under a chip and solder them on before you solder the chip.
Top
 Profile  
Reply with quote  
allisonlastname
 Post subject: Re: shopping list
PostPosted: Wed Aug 16, 2023 9:55 pm 
Offline
User avatar

Joined: Mon Mar 06, 2023 9:26 am
Posts: 88
Location: UK
Slight issue:

Attachment:
2023-08-16_22-54.png
2023-08-16_22-54.png [ 10.12 KiB | Viewed 5403 times ]


But yes, I have seen those boards before and they look useful.

_________________
probably the youngest person on this forum
Top
 Profile  
Reply with quote  
GARTHWILSON
 Post subject: Re: shopping list
PostPosted: Wed Aug 16, 2023 10:17 pm 
Offline
User avatar

Joined: Fri Aug 30, 2002 1:09 am
Posts: 8545
Location: Southern California
No True Scotsman wrote:
No True Scotsman wrote:
They come in various sizes.

Here's one with two rows.

https://www.ebay.com/itm/115271688771

That one has two rows down the middle of the ICs also, which for better for getting good power and ground connections between ICs, since you don't have to go clear out to the sides which increases the inductance.  I also solder the bypass capacitors across these two rows, underneath the ICs, which gives much lower inductance.

Quote:
The "5er" in the description refers to the fact that there are 5 pinholes at each connection point. You'll want to base your purchase on how many jumper wires will be connected to each IC pin. Bear in mind that wide DIPs will obscure some of the holes, but you can usually snake a couple of 22 AWG wires under a chip and solder them on before you solder the chip.

These solder-type breadboards allow you to get more than one wire or lead per hole, so in that sense they're more versatile than the solderless ones.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?
Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  Page 3 of 4
  [ 60 posts ]  Go to page Previous  1, 2, 3, 4  Next

Board index » 6502.org Users Forum » Newbies

All times are UTC


Who is online

Users browsing this forum: No registered users and 37 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
6502.org is an ongoing project by Mike Naberezny and contributors.