Re: Enhanced //e with a 6503??!

[heuser.marcus@freenet.de]

> I recently scored an enhanced //e (verified that it can display
> mousetext and DHGR) -- however, it was sent to me with a processor
> manufactured in mexico, labeled as a 6503.

I guess that you have a "Rockwell 338-6503". This would be the same
chip I have in one of my boards ("International NTSC"-type from 1986,
salvaged from an enhanced French //e).

In one usenet post I read that this is simply another name for the
65C02 made by Rockwell but I don't know if this is correct as there is
another, not totally 65C02-compatible chip: The 65SC02 from GTE, which
does not have the BBR, BBS, RMB, SMB instructions of the 65C02.

> This would NOT be the processor I would expect to find in any apple //e.
> For that matter, my vulcan controller refused to start, crashing to the
> monitor at address $cc20 or so.

This is the first incompatibility I hear with this chip. Though,
admittedly, I haven't tested lots of hard- and software with it.
Especially not software that requires a 65C02.

> Fortunately, I was able to pop in the zip chip from my other //e and
> everything else was working just great afterwards -- so I know that
> the roms are intact and it can pass the onboard diagnostic test.
>
> I read somewhere that the 6503 was a 6502 that could only address
> 4k of memory.  Is this the case?  If so, how the heck would it wind up
> in an enhanced //e manufactured in 1986 and why would it still be in
> the same 40-pin package?

What you and I have, is not a "real" 6503 - otherwise it would have 28
pins, and address space of 4KB and our Apples wouldn't even start ;-)

> Also, I noticed that this //e (MB dated 1986) has much fewer chips,
> noticably the row of 16 * 4k ram chips (like my 1982 //e) was replaced
> by 2 * 32k ram chips.   The 80-column card (also 1986) seems to work
> fine, but is like half the size of my older 1981 model extended 80-col
> card.  Is it just a reduced chip count because of bigger ram chips as
> well?

Your guess is correct - both the mainboard and the 80-column-card have
the usual 64KB. The latter is AFAIK the latest revision on the market.

bye
Marcus