22 Jun
2012
22 Jun
'12
11:15 a.m.
Hi.
I'm looking for any information related to Z80 CPU internals,
microcode, sequencer, etc.
Is it possible to rebuild it in Verilog/VHDL/TTL on breadboard with
all that undocumented instructions, etc?
Here is what I found so far about machine cycles, but obviously, it's
not enough:
http://www.msxarchive.nl/pub/msx/mirrors/msx2.com/zaks/z80prg02.htm
23 Jun
23 Jun
8:34 a.m.
On 22 Jun 2012 at 14:15, Dennis Yurichev wrote:
Hi.
I'm looking for any information related to Z80 CPU internals,
microcode, sequencer, etc.
Is it possible to rebuild it in Verilog/VHDL/TTL on breadboard with
all that undocumented instructions, etc? Here is what I found so far
about machine cycles, but obviously, it's not enough:
http://www.msxarchive.nl/pub/msx/mirrors/msx2.com/zaks/z80prg02.htm
There are several FPGA implementations of the Z80; the first one that
comes to mind is TV80 over at opencores.org in Verilog.
Back in the dark days, someone published an x80 CPU (probably 8080)
done in TTL; perhaps Microcomputing, Kilobaud, DDJ; I don't recall.
--Chuck
9:06 a.m.
Chuck Guzis wrote:
Back in the dark days, someone published an x80 CPU
(probably 8080)
done in TTL; perhaps Microcomputing, Kilobaud, DDJ; I don't recall.
--Chuck
I haven't seen that, but AMD and Signetics both published application
notes containing designs for 8080-compatible processors using bitslice
components, AMD using the Am2900 series, and Signetics using the 3000
series (second-sourced from Intel). IIRC, both are available from
bitsavers. Neither are implemented using logic equivalent to that
inside the original 8080, which is the type of information the OP seemed
to want (but for the Z80 rather than 8080).
5:11 p.m.
On 23 Jun 2012 at 2:06, Eric Smith wrote:
I haven't seen that, but AMD and Signetics both
published application
notes containing designs for 8080-compatible processors using bitslice
components, AMD using the Am2900 series, and Signetics using the 3000
series (second-sourced from Intel). IIRC, both are available from
bitsavers. Neither are implemented using logic equivalent to that
inside the original 8080, which is the type of information the OP
seemed to want (but for the Z80 rather than 8080).
The one I'm thinking of was serialized in at least two installments.
It used 74181 ALUs. The more I think about it, I believe it must
have been an 8080-ish implementation. I suspect that internal
details would have been also pretty far from the real thing--perhaps
microprogrammed using bipolar PROMs instead of a PLA, etc.
Does anyone havet an index to the more serious rags of the 70s era--
Microsystems, Kilobaud, etc.?
--Chuck
2:19 p.m.
http://opencores.org/project,t80
On Fri, 22 Jun 2012, Dennis Yurichev wrote:
Hi.
I'm looking for any information related to Z80 CPU internals,
microcode, sequencer, etc.
Is it possible to rebuild it in Verilog/VHDL/TTL on breadboard with
all that undocumented instructions, etc?
Here is what I found so far about machine cycles, but obviously, it's
not enough:
http://www.msxarchive.nl/pub/msx/mirrors/msx2.com/zaks/z80prg02.htm
2:24 p.m.
On 6/22/2012 5:15 AM, Dennis Yurichev wrote:
Hi.
I'm looking for any information related to Z80 CPU internals,
microcode, sequencer, etc.
Is it possible to rebuild it in Verilog/VHDL/TTL on breadboard with
all that undocumented instructions, etc?
Here is what I found so far about machine cycles, but obviously, it's
not enough:
http://www.msxarchive.nl/pub/msx/mirrors/msx2.com/zaks/z80prg02.htm
Also I belive I read many moons ago, that the Z80 also used the internal
bus capacitance to hold values to be outputted on the external address bus.
Ben.
4571
days inactive
4572
days old
5 comments
5 participants
participants (5)
-
bfranchuk＠jetnet.ab.ca -
cclist＠sydex.com -
cctech＠vax-11.org -
dennis.yurichev＠gmail.com -
eric＠brouhaha.com