Aren't those 6520's just weak-kneed versions of the 6821? I haven't ever
had cause to use a 6520 and I though it was more or less the same in an
identical pinout as the 6821 (maybe the 6521).
Dick
-----Original Message-----
From: Dwight Elvey <elvey(a)hal.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Wednesday, June 23, 1999 3:30 PM
Subject: Re: Quest ELF was Top 150 .....
>Philip.Belben(a)pgen.com wrote:
>>
>>
>> Ethan Dicks wrote:
>>
>> > Now, my junk box is *much* deeper. I could probably assemble an entire
>> > PET PCB and Amiga PCB, just from spares. Thankfully, I don't have to.
>>
>>
>> You mean you actually have spare 6520 chips? How many can you send me
and how
>> much do you want? I have at least one dead one in one of my PETS.
>>
>> Philip.
>
>Hi Philip
> You can buy 6520A's from Jameco. Part number 43246 at $3.75us for
>1-9 and $2.95us for 10+ ( 2.95 was a sale price and may have gone up
>some). You can even deal through the net ( www.jameco.com ).
>Take care
>Dwight
>
>PS
> Of course you could always give me your PET.
>I would give it a good home ;)
>
On Jun 23, 12:22, Ethan Dicks wrote:
> --- Tony Duell <ard(a)p850ug1.demon.co.uk> wrote:
> > What is the (practical) difference between a 6520 and a 6821? They look
> > to be very similar devices IIRC.
>
> I do not know. I do, however, have an abundance of 6821 chips.
As far as I know, there is no practical difference. They are supposed to
be equivalents.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
On Jun 23, 14:53, Philip.Belben(a)pgen.com wrote:
> Ethan Dicks wrote:
>
> > Now, my junk box is *much* deeper. I could probably assemble an entire
> > PET PCB and Amiga PCB, just from spares. Thankfully, I don't have to.
> You mean you actually have spare 6520 chips? How many can you send me
and how
> much do you want? I have at least one dead one in one of my PETS.
They're not hard to get: Rockwell still make 6520s (or at least, suppliers
here still list them), and Hitachi and SGS-Thomson make 6821s, which are
exact replacements (the 68A21 is slighlty faster at 1.5MHz and the 68B21 is
2MHz, but that won't matter). You can get them from Farnell in the UK.
We always used to replace the 6520s with 6820s or 6821s if they failed, as
the 682x seemed to be more robust.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Hi. A while back I was talking with Rodger on the list about the
(appearant) abundance of GridPad 1910's that he was selling.... did th
message t osend money float by me, or are we all still in waiting? And
come to think of it, I haven't seen any messages from Rodger recently...
thanks
Tim
On Jun 23, 20:30, Lawrence LeMay wrote:
> Subject: card edge connectors
> I'm looking to buy several card edge connectors, preferrably with solder
> ends. I'm not exactly sure of the size of the connector though.
>
> Its a 10x2 connector, and the width of each connector&space appears to
> be a tiny bit more than 1.5 times the same measurements from a IBM XT
> expansion card. IE, putting the edge connectors together, 3 connectors
and
> gap spaces on a XT board are almost the same as 2 connectors and gap
> spaces on the connector I need to purchase.
>
> Any ideas of the proper name for what i'm looking for is, and maybe a
> source that I could obtain these from, will be appreciated. I'm
rebuilding
> 20+ year old Terak keyboards, and this will help complete the project.
Sounds like a connector with a 0.156" pitch, which is a standard pitch made
by several companies. Any reasonable electronic supplier should have them.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
I'm looking to buy several card edge connectors, preferrably with solder
ends. I'm not exactly sure of the size of the connector though.
Its a 10x2 connector, and the width of each connector&space appears to
be a tiny bit more than 1.5 times the same measurements from a IBM XT
expansion card. IE, putting the edge connectors together, 3 connectors and
gap spaces on a XT board are almost the same as 2 connectors and gap
spaces on the connector I need to purchase.
Any ideas of the proper name for what i'm looking for is, and maybe a
source that I could obtain these from, will be appreciated. I'm rebuilding
20+ year old Terak keyboards, and this will help complete the project.
-Lawrence LeMay
lemay(a)cs.umn.edu
Ethan Dicks wrote:
> Now, my junk box is *much* deeper. I could probably assemble an entire
> PET PCB and Amiga PCB, just from spares. Thankfully, I don't have to.
You mean you actually have spare 6520 chips? How many can you send me and how
much do you want? I have at least one dead one in one of my PETS.
Philip.
>>>>> "Tony" == Tony Duell <ard(a)p850ug1.demon.co.uk> writes:
Tony> I have a daybreak. To confirm it's the same machine, it's a
Tony> brown tower case with 5 card slots on the back. From the
Tony> left (looking at the back), they are :
Tony> Memory/video Spare (memory expansion?) Mesa Processor Board
Tony> I/O Processor Board Spare (Optional I/O)
Tony> To the right of those there's a fold-down door with the PSU
Tony> and hard disk behind it. The floppy drive (and tape streamer
Tony> on my machine) are separate boxes that stack on top of the
Tony> main tower.
I have all slots full, I cannot confirm the order right now,
but it seems right to me. In my unit, the PSU e ontop the harddisk,
and there are three fans on the bottom of the case, that slide just
like a rack (I guess it's even numbered after all the other boards),
after a couple of screws have been removed.
Tony> I also have a monitor - a big (Samtron?) monochrome
Tony> thing. What I don't have is the keyboard or mouse. The
Tony> keyboard plugs into the 5 pin DIN socket on the monitor
Tony> base, the mouse, I believe, plugs into the keyboard.
Hum, one of the boards of my unit, the one with the floppy
interface, ethernet, and serial ports, has a DB9 conector labeled
keyboard. But I found a couple of extra lines in the DB15 monitor
connector besides video and sync signals...
Tony> I am told that hardwre documentation and especially
Tony> schematics for this machine are impossible to obtain. When I
Tony> have time, I'll attack my machine with a logic analyser and
Tony> try to figure out something about it. But that won't happen
Tony> soon, I'm afraid.
Thanks for the info anyway.
Cheers,
--
*** Rodrigo Martins de Matos Ventura <yoda(a)isr.ist.utl.pt>
*** Teaching Assistant and MSc. Student at ISR:
*** Instituto de Sistemas e Robotica, Polo de Lisboa
*** Instituto Superior Tecnico, Lisboa, Portugal
*** PGP Public Key available on my homepage:
*** http://www.isr.ist.utl.pt/~yoda
*** Key fingerprint = 0C 0A 25 58 46 CF 14 99 CF 9C AF 9E 10 02 BB 2A
>I'm looking to buy several card edge connectors, preferrably with solder
>ends. I'm not exactly sure of the size of the connector though.
>
>Its a 10x2 connector, and the width of each connector&space appears to
>be a tiny bit more than 1.5 times the same measurements from a IBM XT
>expansion card. IE, putting the edge connectors together, 3 connectors and
>gap spaces on a XT board are almost the same as 2 connectors and gap
>spaces on the connector I need to purchase.
Common pitches for card edge connectors are 0.1", 0.125", 0.156", and
0.24". The ISA-bus connector is 0.1" pitch, so I'm willing to bet you
want a 0.156" pitch card edge connector.
>Any ideas of the proper name for what i'm looking for is, and maybe a
>source that I could obtain these from, will be appreciated. I'm rebuilding
>20+ year old Terak keyboards, and this will help complete the project.
You're lucky that you're in the same state with one of the best
distributors for card edge connectors, Digikey. Go to http://www.digikey.com/
and you'll find that EDAC and Sullins make edge connectors like what
you want, with your choice of solder tail or solder eyelet terminations.
For your use, it sounds like you want to put wires on the edge connectors,
so I'm guessing that you want the solder eyelet termination, in which case
you want EDAC 305-020-520-202, Digikey EDC307200-ND, which will cost
you exactly $1.98.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
If you compare the pin spacing with that of the classic 44-pin edge
connector, you may find it's the same, based on what you wrote. I'd guess
it's 0.15625" spacing. There are really only three typical spacings from
the old days: 5/32", 1/8", and 1/10".
The S-100 used 1/8" while the ISA Bus connectors used 0.100. The old
KIM-Bus was 5/32".
Is that the info you needed?
Dick
-----Original Message-----
From: Lawrence LeMay <lemay(a)cs.umn.edu>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Wednesday, June 23, 1999 2:36 PM
Subject: card edge connectors
>I'm looking to buy several card edge connectors, preferrably with solder
>ends. I'm not exactly sure of the size of the connector though.
>
>Its a 10x2 connector, and the width of each connector&space appears to
>be a tiny bit more than 1.5 times the same measurements from a IBM XT
>expansion card. IE, putting the edge connectors together, 3 connectors and
>gap spaces on a XT board are almost the same as 2 connectors and gap
>spaces on the connector I need to purchase.
>
>Any ideas of the proper name for what i'm looking for is, and maybe a
>source that I could obtain these from, will be appreciated. I'm rebuilding
>20+ year old Terak keyboards, and this will help complete the project.
>
>-Lawrence LeMay
> lemay(a)cs.umn.edu
