6526 - 8520A-1 and 6502 - 6500/1
Daniel Karlsson
Will I be facing any incompabilities if exchanging a 6526 with an Amiga's
8520A-1? The pin layout seems to be the same, so I just thought that I would
check with you and se if someone already tried this. Dito for the
6502-6500/1 chip (and any other chip in a Amiga 500 that I might have
missed).
--
/djk
remove ".nospam" for reply
Michael J. Schülke
> Will I be facing any incompabilities if exchanging a 6526 with an Amiga's
> 8520A-1? The pin layout seems to be the same, so I just thought that I would
> check with you and se if someone already tried this.
I haven't tried it myself, but I remember reading in an Amiga Hardware
book that you could do that "in an emergency". Whatever that is supposed
to mean.
Regards,
Michael
Jaque Moreau
boards? I noticed they are labeled slightly different and I've heared of
some incompatibilities with the short board but I don't know if theese
incompatibilities are due to the CIAs.
Daniel Karlsson
news:slrnbdu051....@matthias.bachert...
Those (6526 and 8521) should be exchangable. I have a 64 with one each from
factory (250466 board). I think it's just the manufacturing method that is
different in those two (NMOS and CMOS respectively). The incompatilibies
that you are thinking of is probably the thing with the SID-chip. The SID's
aren't directly exchangable. I could be wrong, correct me if so.
--
/djk, of to fetch his new C128DCR wich just arrived from Germany
remove ".nospam" for reply
Miika Seppänen
<d....@nospam.telia.com> wrote:
>Hi!
>
>Will I be facing any incompabilities if exchanging a 6526 with an Amiga's
>8520A-1? The pin layout seems to be the same, so I just thought that I would
>check with you and se if someone already tried this. Dito for the
>6502-6500/1 chip (and any other chip in a Amiga 500 that I might have
>missed).
In one of my C64s there's a 8520R0A factory-installed as CIA2. (I've a
scan of the board in
http://www.sci.fi/~miksukka/Kuvat/C64C_250466vasen.jpg The picture is
about 402KB.)
-Miika
Steppe
> The incompatilibies that you are thinking of is probably the thing
> with the SID-chip. The SID's aren't directly exchangable. I could be
> wrong, correct me if so.
You are partly wrong. The 6581 and 8580 are pin compatible, hence they're
interchangable.
However there are some strong arguments that should prevent you from doing
this:
The 6581 and the 8580 use a different core voltage (9V vs. 12V). None of the
chips obviously likes the voltage of the other too much, so they'll both
cross the Jordan sooner or later (rather sooner). Besides each chip has a
specific set of filter capacitors that affect the sound greatly. Even _if_
you'd exchange it, and assumed it would work for a while, the filters would
sound very strange.
/Stephan
--
www.demodungeon.com
-> for your daily dose of demos!
Daniel Karlsson
"Miika Seppänen" <miika.seppan...@saunalahti.fi> skrev i
meddelandet news:1l8udvc1ninlugrtu...@4ax.com...
Thanks for your answer, but I already knew that, I have one of these boards
myself. Apparantly the 8521R0A (not 8520R0A) are the same chip as 6526 but
in CMOS, but how about 8520A-1? The obvious question is: why make exactly
the same chip with two different model numbers? There have to be some
differences betwen them, but what and is it significant? Here is a page with
info on the 8520, where 6526 is said to be the predecessor to the 8520:
http://www.amiga-stuff.com/hardware/8520.html.
Cheers
MagerValp
DK> Will I be facing any incompabilities if exchanging a 6526 with an
DK> Amiga's 8520A-1? The pin layout seems to be the same, so I just
DK> thought that I would check with you and se if someone already
DK> tried this.
The 8520 doesn't have TOD circuitry.
--
___ . . . . . + . . o
_|___|_ + . + . + . Per Olofsson, arkadspelare
o-o . . . o + Mage...@cling.gu.se
- + + . http://www.cling.gu.se/~cl3polof/
Daniel Karlsson
"MagerValp" <Mage...@cling.gu.se> skrev i meddelandet
news:p1465nk...@panini.cling.gu.se...
> >>>>> "DK" == Daniel Karlsson <d....@nospam.telia.com> writes:
>
> DK> Will I be facing any incompabilities if exchanging a 6526 with an
> DK> Amiga's 8520A-1? The pin layout seems to be the same, so I just
> DK> thought that I would check with you and se if someone already
> DK> tried this.
>
> The 8520 doesn't have TOD circuitry.
>
Are you absolutely sure about that? Because according to this page the
DIL-package 8520 (for 500, 1000 etc.) has TOD on pin 19:
http://www.amiga-stuff.com/hardware/8520.html. Se also:
http://www.savel.org/old/amiga/pinouts.html.
I have by the way gotten my 128DCR now, but I'm not all that sure that I
want to change to the swedish charroms. The german char is far more readable
and I don't really need the swedish charroms. I can always boot GEOS if I
want the swedish characters. Well I haven't decided yet...
Cheers
Nicolas Welte
> "MagerValp" <Mage...@cling.gu.se> skrev i meddelandet
> news:p1465nk...@panini.cling.gu.se...
>
>>>>>>>"DK" == Daniel Karlsson <d....@nospam.telia.com> writes:
>>
>>DK> Will I be facing any incompabilities if exchanging a 6526 with an
>>DK> Amiga's 8520A-1? The pin layout seems to be the same, so I just
>>DK> thought that I would check with you and se if someone already
>>DK> tried this.
>>
>>The 8520 doesn't have TOD circuitry.
>>
>
>
>
> Are you absolutely sure about that? Because according to this page the
> DIL-package 8520 (for 500, 1000 etc.) has TOD on pin 19:
The 8520 datasheet mislabels the pin as TOD (Time Of Day), because it is just
a direct input to a 24bit binary counter. The BCD logic and the selectable
divider stage (/5 or /6) is missing in this chip.
Nicolas
--
--> Email address is valid for replies (requires Re: in the subject) <--
- See my Commodore hardware projects at http://people.freenet.de/x1541 -
- Visit the German X1541 Shop at http://sta.c64.org/x1541shop_ger.html -
Nicolas Welte
They are, but the incompatibilities are caused by internal changes in the
CIA, they are still pin compatible. It's something with the timers that
generate IRQs one cycle too early on the late 6526 (manufactered late '86 or
later). I learnt it the hard way when I bought a replacement CIA for my old
C64 in '87 or so and some programs would not work anymore!
BTW, it's strange that the 8520 (manufactured from '85 to '94) and 8521 (only
made in '86?) have the old timer behaviour, so for some programs a 8520 will
work better than a late 6526! Maybe the late 6526 was produced in yet another
chip process than the early 65xx (NMOS) and the 65xx (HMOS-II). Maybe they're
CMOS? Might be another task for Tim Boescke to check this out :)
Ronald van Dijk
>> DK> Will I be facing any incompabilities if exchanging a 6526 with an
>> DK> Amiga's 8520A-1? The pin layout seems to be the same, so I just
>> DK> thought that I would check with you and se if someone already
>> DK> tried this.
>>
>> The 8520 doesn't have TOD circuitry.
>>
>Are you absolutely sure about that? Because according to this page the
>DIL-package 8520 (for 500, 1000 etc.) has TOD on pin 19:
>http://www.amiga-stuff.com/hardware/8520.html. Se also:
>http://www.savel.org/old/amiga/pinouts.html.
The 8520 does not have a TOD (Time Of Day) clock, but it has a general
purpose 24-bit counter instead. But the name TOD for the input pin and
the registers was kept when the 8520 was created.
Regards,
Ronald
Ronald van Dijk
>Will I be facing any incompabilities if exchanging a 6526 with an Amiga's
>8520A-1? The pin layout seems to be the same, so I just thought that I
>would check with you and se if someone already tried this. Dito for the
>6502-6500/1 chip (and any other chip in a Amiga 500 that I might have
>missed).
The 6500/1 is a one chip microcomputer. It is based around a 6502 core, and
it has internal ROM, RAM, a counter and I/O. It has no external address,
data and control busses, but has 32 I/O pins instead. This all means that a
6500/1 can not be used instead of a 6502 microprocessor.
Furthermore, a 6500/1 can only be replaced by one that has the same (or a
compatible) program in ROM.
Regards,
Ronald
Daniel Karlsson
news:3edf9c9e$0$49098$e4fe...@news.xs4all.nl...
Cheers
Daniel Karlsson
Thank you both Nicolas and Ronald. One place one should be able to use it
would be in the 1571, right? Maby someone should inform the owner of that
site about this.
Regards
Ronald van Dijk
>> >> DK> Will I be facing any incompabilities if exchanging a 6526 with an
>> >> DK> Amiga's 8520A-1? The pin layout seems to be the same, so I just
>> >> DK> thought that I would check with you and se if someone already
>> >> DK> tried this.
>> >>
>> >> The 8520 doesn't have TOD circuitry.
>> >>
>> >Are you absolutely sure about that? Because according to this page the
>> >DIL-package 8520 (for 500, 1000 etc.) has TOD on pin 19:
>> >http://www.amiga-stuff.com/hardware/8520.html. Se also:
>> >http://www.savel.org/old/amiga/pinouts.html.
>>
>> The 8520 does not have a TOD (Time Of Day) clock, but it has a general
>> purpose 24-bit counter instead. But the name TOD for the input pin and
>> the registers was kept when the 8520 was created.
>
>Thank you both Nicolas and Ronald. One place one should be able to use it
>would be in the 1571, right? Maby someone should inform the owner of that
>site about this.
Yes, in the 1571 either the 6526 or the 8520 can be used.
Regards,
Ronald
"Patryk 'Silver Dream !' Łogiewa"
No, the CIAs are the same, even if they are labeled differently due to
different series, manufacturer's name etc.
"Patryk 'Silver Dream !' Łogiewa"
> "Jaque Moreau" <mr.w...@firemail.de> skrev i meddelandet
> news:slrnbdu051....@matthias.bachert...
>
>>BTW: are the CIAs in a short board exchangable with those in the long
>>boards? I noticed they are labeled slightly different and I've heared of
>>some incompatibilities with the short board but I don't know if theese
>>incompatibilities are due to the CIAs.
>
>
> Those (6526 and 8521) should be exchangable. I have a 64 with one each from
> factory (250466 board). I think it's just the manufacturing method that is
> different in those two (NMOS and CMOS respectively). The incompatilibies
> that you are thinking of is probably the thing with the SID-chip. The SID's
> aren't directly exchangable. I could be wrong, correct me if so.
the SID's the VIC's, the PLA...
"Patryk 'Silver Dream !' Łogiewa"
>>>>>>"DK" == Daniel Karlsson <d....@nospam.telia.com> writes:
>
>
> DK> Will I be facing any incompabilities if exchanging a 6526 with an
> DK> Amiga's 8520A-1? The pin layout seems to be the same, so I just
> DK> thought that I would check with you and se if someone already
> DK> tried this.
>
> The 8520 doesn't have TOD circuitry.
>
It does...
"Patryk 'Silver Dream !' Łogiewa"
> Daniel Karlsson wrote:
>
>> "MagerValp" <Mage...@cling.gu.se> skrev i meddelandet
>> news:p1465nk...@panini.cling.gu.se...
>>
>>>>>>>> "DK" == Daniel Karlsson <d....@nospam.telia.com> writes:
>>>
>>>
>>> DK> Will I be facing any incompabilities if exchanging a 6526 with an
>>> DK> Amiga's 8520A-1? The pin layout seems to be the same, so I just
>>> DK> thought that I would check with you and se if someone already
>>> DK> tried this.
>>>
>>> The 8520 doesn't have TOD circuitry.
>>>
>>
>>
>>
>> Are you absolutely sure about that? Because according to this page the
>> DIL-package 8520 (for 500, 1000 etc.) has TOD on pin 19:
>
>
> The 8520 datasheet mislabels the pin as TOD (Time Of Day), because it is
> just a direct input to a 24bit binary counter. The BCD logic and the
> selectable divider stage (/5 or /6) is missing in this chip.
>
I remember (off my head) the block schematics of 8520 with all the TOD
circuitry in there, including the connection to interrupt mask filter
etc. Would need to dig my old paper docs to eventually scan them.
"Patryk 'Silver Dream !' Łogiewa"
TOD was left but there is only the 24bit counter... Means that you were
also right ;-)
"Patryk 'Silver Dream !' Łogiewa"
Yep. You were (as usual) right. I think I should have remembered better
but - you know - time flies...
Thus, what's left of the TOD is the name of the block and the counter there.