Re: Signetics Datasheets for Apple 1 Project

["logjam" <grant@cmosxray.com>]

Yes.  I've been able to see all the fuses at 200x mag.  I knew the
difference between PAL and HAL which is why I was even more curious
about what the "fuses" would look like in a HAL.  You can see in the
images below that a HAL has all the fuses, but some have been cut.  So
my guess would be rather than them being manufactured with a pattern,
they are manufactured 100% connected and then mechanically cut later?

Here is a huge picture of the entire silicon.  The fuse map is the big
rectangle array to the left.  50x
http://media.diywelder.com/images3/091205-wholechip_IMGP2074.jpg

Here is a 20pin DIP with an arrow pointing to the map.  Its amazing the
scale inside these chips...and they're 30 years old!  :)
http://media.diywelder.com/images3/091205-HALchip_IMGP2078.jpg

Here is one 8x32 256 fuse array with the inputs and flip flop results
annotated.  200x
http://media.diywelder.com/images3/091205-FusemapMap-IMGP2067.jpg

A shot of the bond wires, 200x.
http://media.diywelder.com/images3/091205-Pins_IMGP2070.jpg

MMI logo 200x
http://media.diywelder.com/images3/091205-MMILogo_IMGP2051.jpg


Those pictures were of the ASG, Apple Sound Generator, in the 128k to
Plus macintosh.  I'm going to write a program to visually read the
fusemap so that I don't have to.  There are 6 PALs in the Macintosh,
and Henry has a few dozen others...

Pretty cheap, $45 for a chemical decap and then a few hours writing a
program.  Done, PALs copied.  :)