Re: Apple I schematics?

["sfbong" <sfbong@tm.net.my>]

"Byron Desnoyers Winmill" <wbdesnoy@acs5.acs.ucalgary.ca> wrote in message
news:9vrecd$5vk$2@nserve1.acs.ucalgary.ca...
> I think that there are some schematics here:
>
> http://www.applefritter.com/apple1/index.html
>
> But I'm running lynx right now, so it is hard to be sure.  :-)
>
> Byron.




The circuit seems interesting so I downloaded all 4 of them.  I have a few
questions here:

1. What are all these chips
  2504 at D5
  2519 at C3
  2513 at D2
  DS0025 at terminal section.

2  Can DM8097 be replaced by 74LS367 or 74LS245?

3. If I replace all the DRAM with a 6264 and remove the 2 multiplexers B5 &
B6.  Would it affect the working of the video circuitry ?  Is the video
display memory inside the main RAM ?

4. Can the 6820 be replaced by 6821 ?

5.  Are the 2 PROM chips in the cassette interface the same chips as in the
processor section A1 & A2 ?


Allen