From Newsgroup: comp.sys.apple2

Yesterday, I took a look at the circuit diagrams and schematics of an
Apple II found in the Apple II Reference Manual (the Red Book.) I was
struck with the number of components used, but also with their
commonality. In an original Apple II, there does not seem to be any
custom chips or devices, unlike the later Apple IIes and IIcs. Most
of the Apple II/II+ seems composed of standard TTL logic chips. The
6502 CPU can be found. The ROM, all 12-16KB of it, can easily fit on
one EPROM. 48KB of DRAM can be done with two chips. The connectors
are probably standard. Of course, one does not have to build a power
supply and can use an Apple II keyboard. So, has anybody ever
constructed an Apple II mainboard in the way I have described?

GH
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From Newsgroup: comp.sys.apple2

Nearly 20 years ago several friends and wirewrapped quite a number of
Apple ][+s. Of course we used the same chips as Apple did but it would
be a good project. The circuits timings would probably be the critical
part. In our experiments the chip types LS, S and so on were required
in the correct positions.

Bill

On 14 Jul 2003 16:57:21 -0700, great_hierophant@hotmail.com (Great
Hierophant) wrote:

Yesterday, I took a look at the circuit diagrams and schematics of an
Apple II found in the Apple II Reference Manual (the Red Book.) I was
struck with the number of components used, but also with their
commonality. In an original Apple II, there does not seem to be any
custom chips or devices, unlike the later Apple IIes and IIcs. Most
of the Apple II/II+ seems composed of standard TTL logic chips. The
6502 CPU can be found. The ROM, all 12-16KB of it, can easily fit on
one EPROM. 48KB of DRAM can be done with two chips. The connectors
are probably standard. Of course, one does not have to build a power
supply and can use an Apple II keyboard. So, has anybody ever
constructed an Apple II mainboard in the way I have described?

GH

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From Newsgroup: comp.sys.apple2

Great Hierophant observed:

Yesterday, I took a look at the circuit diagrams and schematics of an
Apple II found in the Apple II Reference Manual (the Red Book.) I was
struck with the number of components used, but also with their
commonality. In an original Apple II, there does not seem to be any
custom chips or devices, unlike the later Apple IIes and IIcs. Most
of the Apple II/II+ seems composed of standard TTL logic chips. The
6502 CPU can be found. The ROM, all 12-16KB of it, can easily fit on
one EPROM. 48KB of DRAM can be done with two chips. The connectors
are probably standard. Of course, one does not have to build a power
supply and can use an Apple II keyboard. So, has anybody ever
constructed an Apple II mainboard in the way I have described?

Steve Wozniak worked at HP Laboratories, and the Apple II was
constructed from parts available from lab stock (with the exception
of the 6502 itself).

HP at that time encouraged engineers to engage in projects on
their own time, and happily supplied the parts. Very enlightened.

The result is that the Apple ][ and ][+ are easily constructed from
stock parts, and many were built like this in the early days, when
$1200 was a little steep for a device with $200 worth of parts. ;-)

-michael

Check out amazing quality 8-bit Apple sound on my
Home page: http://members.aol.com/MJMahon/
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From Newsgroup: comp.sys.apple2

mjmahon@aol.com (Michael J. Mahon) wrote in message news:<20030715024834.02823.00000128@mb-m02.aol.com>...

Great Hierophant observed:

Yesterday, I took a look at the circuit diagrams and schematics of an
Apple II found in the Apple II Reference Manual (the Red Book.) I was >struck with the number of components used, but also with their
commonality. In an original Apple II, there does not seem to be any
custom chips or devices, unlike the later Apple IIes and IIcs. Most
of the Apple II/II+ seems composed of standard TTL logic chips. The
6502 CPU can be found. The ROM, all 12-16KB of it, can easily fit on
one EPROM. 48KB of DRAM can be done with two chips. The connectors
are probably standard. Of course, one does not have to build a power >supply and can use an Apple II keyboard. So, has anybody ever
constructed an Apple II mainboard in the way I have described?

Steve Wozniak worked at HP Laboratories, and the Apple II was
constructed from parts available from lab stock (with the exception
of the 6502 itself).

HP at that time encouraged engineers to engage in projects on
their own time, and happily supplied the parts. Very enlightened.

The result is that the Apple ][ and ][+ are easily constructed from
stock parts, and many were built like this in the early days, when
$1200 was a little steep for a device with $200 worth of parts. ;-)

-michael

Check out amazing quality 8-bit Apple sound on my
Home page: http://members.aol.com/MJMahon/

LOL, I once suggested to someone the possibility of building a 48K
Apple ][+ with a PS/2 keyboard port and disk ][ emulation into a
Commodore 1541 disk drive (also 6502-driven). :)

I wonder if it would be possible...

-uso.
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From Newsgroup: comp.sys.apple2


"Dosius" <steve@dosius.zzn.com> wrote

LOL, I once suggested to someone the possibility of building a 48K
Apple ][+ with a PS/2 keyboard port and disk ][ emulation into a
Commodore 1541 disk drive (also 6502-driven). :)

I wonder if it would be possible...

I thought it would be kind of cool to build a tiny Apple II using the fewest number of modern chips, modern connection ports, and with everything "built
in" -sort of like that new Commodore One system, which is for sale now BTW. That Jeri Ellsworth is kinda cute, too.

http://www.pegasos-uk.com/pictures/photos/arc2002/aachen_067.jpg

http://www.pegasos-uk.com/pictures/photos/arc2002/aachen_178.jpg



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From Newsgroup: comp.sys.apple2

Ernest wrote:

I thought it would be kind of cool to build a tiny Apple II using the fewest number of modern chips, modern connection ports, and with everything "built in" -sort of like that new Commodore One system, which is for sale now BTW.

Errm... Where? AFAIK, shipping the boards has been delayed until the
cores are (somewhat) finished.

Regards,
Michael
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From Newsgroup: comp.sys.apple2

Ernest <leucoplast@seanet.NOSPAM.com> wrote in message news:LDRQa.57836$wk6.14226@rwcrnsc52.ops.asp.att.net...

I thought it would be kind of cool to build a tiny Apple II using the

fewest

number of modern chips, modern connection ports, and with everything

"built

in" -sort of like that new Commodore One system, which is for sale now

BTW.

That Jeri Ellsworth is kinda cute, too.

I expect that all of the TTL latches and glue logic could be incorporated
into a single PLA/PLD by now, but the 6502/65816 core probably still
requires a chip all by itself. The most efficient design would probably require 4-5 chips including:
- PLA or PLD for glue logic and latches
- CPU (e.g. 65816)
- Memory module (e.g. an 8 Meg SIMM)
- 1 or 2 analog interface chips



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From Newsgroup: comp.sys.apple2

Dosius (steve@dosius.zzn.com) writes:

mjmahon@aol.com (Michael J. Mahon) wrote in message news:<20030715024834.02823.00000128@mb-m02.aol.com>...

Great Hierophant observed:

Yesterday, I took a look at the circuit diagrams and schematics of an
Apple II found in the Apple II Reference Manual (the Red Book.) I was
struck with the number of components used, but also with their
commonality. In an original Apple II, there does not seem to be any
custom chips or devices, unlike the later Apple IIes and IIcs. Most
of the Apple II/II+ seems composed of standard TTL logic chips. The
6502 CPU can be found. The ROM, all 12-16KB of it, can easily fit on
one EPROM. 48KB of DRAM can be done with two chips. The connectors
are probably standard. Of course, one does not have to build a power
supply and can use an Apple II keyboard. So, has anybody ever
constructed an Apple II mainboard in the way I have described?

Steve Wozniak worked at HP Laboratories, and the Apple II was
constructed from parts available from lab stock (with the exception
of the 6502 itself).

HP at that time encouraged engineers to engage in projects on
their own time, and happily supplied the parts. Very enlightened.

The result is that the Apple ][ and ][+ are easily constructed from
stock parts, and many were built like this in the early days, when
$1200 was a little steep for a device with $200 worth of parts. ;-)

-michael

Check out amazing quality 8-bit Apple sound on my
Home page: http://members.aol.com/MJMahon/

LOL, I once suggested to someone the possibility of building a 48K
Apple ][+ with a PS/2 keyboard port and disk ][ emulation into a
Commodore 1541 disk drive (also 6502-driven). :)

I wonder if it would be possible...

I doubt it. I'm pretty sure the "6502" in that drive is one of
the stunted ones, which don't have all the 16 address lines coming out
of it. I can't remember if I read that somewhere, or saw it directly.

It also has limited memory. And since one of the Apple II's claim to
faims is the nifty arrangement for refreshing RAM and displaying characters
on a screen with the same circuitry, terribly extensive work would have
to be done to add that to an existing 6502 board.

In other words, it would be easier to start from scratch than to try
to make an Apple II out of an existing 6502 board.

Michael

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From Newsgroup: comp.sys.apple2

<< You should be able to program the entire thing into one of the larger FPGA chips available at the moment, or at least 90% of the logic.

About the same as pulling the //e chip from the IIGS?
Jay
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From Newsgroup: comp.sys.apple2

Michael Pender schrieb:

I expect that all of the TTL latches and glue logic could be incorporated into a single PLA/PLD by now, but the 6502/65816 core probably still
requires a chip all by itself.

Many 6502 ("RISC") cores are available as VHDL code for free. You can
build an Apple II system using a few FPGA chips plus memory. If you want
to pay for a 'real' ASIC, SRAM and flash ROM can be included, too. This
would allow you to build a single-chip apple.

http://www.free-ip.com/6502/index.html

Patrick
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