please describe, in your opinion, which should be the hardware characteristics of an "ideal" standalone Z80-based retro computer!
Ok,
let me "break the ice"...
My ideal Z80 standalone computer should have:
- overclocked Z80 (20 - 25 MHz would be nice...)
- 16/32 KB EPROM (nice to have, but not a must...)
- at least 128 KB banked RAM (512 KB banked would be best)
- CF (32 MB is quite enough for me...)
- PS/2 keyboard interface
- VGA monitor interface (80 x 24 8x8 pixels chars would be best, but 64 x 48, monochrome is enough for me...)
- serial to USB ( I prefer SIO/KIO, programmable up to 112500 bauds )
- Real Time Clock
- digital I/O module, 8 leds (nice to have...)
Ladislau
...perhaps "The ideal standalone Z80-based homebrew computer" is a better choice... anyway, that's what I was thinking about, when I wrote the message!
Ladislau
please describe, in your opinion, which should be the hardware characteristics of an "ideal" standalone Z80-based retro computer!
It would be nice to have a banking scheme that works well both for MP/M
and FUZIX, and serial ports that are capable of running reliably at high speeds (115200+ baud).
I've designed and built a couple of standalone Z80 based SBC's:can be accessed, but I haven't experimented with bank switching at all. It has a 32k x 8 ROM that contains a monitor, a CP/M 2.2 image, and some utilities. The ROM can be switched out of the memory map for a (roughly) 55k TPA. The most interesting
One is quite small (maybe 4.75" x 3.75"). It runs at 20 MHz with a full sixteen 8 MB "disks" on compact flash. It has two serial ports running at 115k baud (one used as a console) via a Z84C4010PEC. It uses a 128k x 8 SRAM. The two 64k x 8 halves
The second is quite a bit larger (maybe 5" x 7"). Same basic features of the Z80 described above, but this one uses a Z85C30 UART for two serial ports (one used as console). It is fully through hole 74LS, and has a fully TTL compact flash interface.It can be configured for 32k or 16k banks (using a 512k x 8 SRAM), but again I have not done much with that. It has a DS1302 RTC (battery backed). It also has a native USB port based on the DLP-USB245R that is amazingly fast! Again, a monitor, CP/M 2.
I'd post photos of both of these Z80's, but I can't see a way to do that here.
As is usually the case, the price of function is complexity, so some of the "wish lists" posted here would possibly have to be constrained by that old adage!
Roger
Would a 20MHZ z80 (or more) be able to play Zmachine games (z5 and z8 version)
with enough speed? I think the 6502 on the C64 with a REU it's able to play Z5 games with a few seconds delay and Z8 games run very slow.
You know, the interpreter to run Infocom games, but there are several "amateur" (not so amateur since the 1993's game 'Curses!'). games to try.
Bear in mind Z3 games will run fine in any 8bit machine, but for Z8
games a 286.386, or 68k machine it's expected.
What do you think about this one: https://www.thebyteattic.com/p/agon.html Is it close to your ideal?
And here's CP/M 2.2 for the machine: https://github.com/nihirash/Agon-CPM2.2
It is a ez80 computer, not a Z80 one...
eZ80 has two modes of operaion: Z80 mode and eZ80 ADL mode (ADL Mode is offered to provide code execution time that is four times faster than that of a standard Z80 CPU operating at the same clock speed).
So you can operate it in its Z80 mode.
Ok, I agree that eZ80 can operate in Z80 mode, but, how about some other hardware items that are Z80 compatible, and can even run CP/M ?
Well, in my opinion, in this thread we should discuss only about standalone retro/homebrew computers provided with the Z80 CPU.
The "real" Z80 (Z84C00) or its "clones" (e.g. MK3880, LH0080, U880, MMN80CPU, ...) , with clock frequencies up to 20MHz.
Not Z180/Z280/Z800/R800/eZ80 ...
The "real" Z80 (Z84C00) or its "clones" (e.g. MK3880, LH0080, U880, MMN80CPU, ...) , with clock frequencies up to 20MHz.
Not Z180/Z280/Z800/R800/eZ80 ...
Ok, why don't you open a new conversation, with the title "The ideal standalone Z80-compatible retro/homebrew computer" ?
AgonLight is fit to be presented there...
Ok, why don't you open a new conversation, with the title "The ideal standalone Z80-compatible retro/homebrew computer" ?
AgonLight is fit to be presented there...
AgonLight is also fit to be presented here.
Consider one more example: in former East Germany they manufactured
Z80 clone named U880. So you would exclude the machine fitted with U880
from this thread, because its CPU didn't have proud „Z80” print on its package?
I thought you were serious by stating:
”different opinions should always be acknowledged and accepted... and
I will also comply with this rule of common sense”
It seems I was wrong.
But OK, then leaving this thread to not bother you with different opinion. Bye!
Consider one more example: in former East Germany they manufactured
Z80 clone named U880. So you would exclude the machine fitted with U880 from this thread, because its CPU didn't have proud „Z80” print on its package?
Ladislau has a lot of things right, Z80 based is not the same as Z80 compatible. Compatibility is a term that covers a broader spectrum, there can be Z80, "Super-Z80" like Z180, Z280, eZ80, hardware emulations on FPGA and software emulations on anyother architecture.
How do I understand "know better"? You think the eZ80 is the only right choice, then so be it,
Why do you think it excludes most new projects? This year I designed two RCBus modules using the Z80. Also, a module on the Z280 supported by
a contemporary AVR microcontroller was also created. One may wonder
if such solutions can be called "retro", but certainly the Z80 modules are based on the Z80, and the Z280 is a Z80-compatible processor.
How do I understand "know better"? You think the eZ80 is the only right choice, then so be it, it is your opinion and I don't necessarily have to agree with it. The AgonLight is a great computer, but it is not the only right choice for Z80 supporters.The discussion is starting to resemble direct marketing - either AgonLight with eZ80 or you don't know. Everyone has different expectations from such a system and everyone can find what suits them. The performance argument does not appeal to me, there
Why do you think it excludes most new projects? This year I designed two RCBus modules using the Z80. Also, a module on the Z280 supported by a contemporary AVR microcontroller was also created. One may wonder if such solutions can be called "retro",but certainly the Z80 modules are based on the Z80, and the Z280 is a Z80-compatible processor. The whole charm of such solutions lies in the use of technology from that period.
Why spend the money then? Nowadays, there are excellent PC emulators that far outperform any Z80-compatible hardware solution.
If we feel the need for separate hardware, we can emulate the entire CP/M environment on an inexpensive ESP32, which can also be found on AgonLite, using the RunCPM project. In each of these examples, we can enjoy convenience and performance. Whatdistinguishes these solutions from the typical "slow" modular Z80 system is the lack of expandability. It is a closed system, with no freedom to add any extensions.
Why spend the money then? Nowadays, there are excellent PC emulators that far outperform any Z80-compatible hardware solution.
Therefore, for me personally, there is no difference between closed hardware solutions and emulators, and if I had
to choose between the two, I would prefer the emulator
I'm still looking for that 'excellent' MS-DOS emulator (which I'll use with MYZ80)
On Wednesday, 23 August 2023 at 07:10:31 UTC+1, dxforth wrote:
I'm still looking for that 'excellent' MS-DOS emulator (which I'll use with MYZ80)
try this http://www.vdosplus.org/
On 25/08/2023 4:37 pm, Chris Syntichakis wrote:
On Wednesday, 23 August 2023 at 07:10:31 UTC+1, dxforth wrote:
I'm still looking for that 'excellent' MS-DOS emulator (which I'll use with MYZ80)
try this http://www.vdosplus.org/Thanks. MYZ80 boots on it but doing anything cause a crash e.g. DIR gives me a
page then freezes. Original DOSBOX has its quirks but generally works.
Why spend the money then? Nowadays, there are excellent PC emulators that far outperform any Z80-compatible hardware solution. If we feel the need for separate hardware, we can emulate the entire CP/M environment on an inexpensive ESP32, which can alsobe found on AgonLite, using the RunCPM project. In each of these examples, we can enjoy convenience and performance. What distinguishes these solutions from the typical "slow" modular Z80 system is the lack of expandability. It is a closed system, with
I really don't understand the urge to "push" a Z80 to 20, 50, 100Mhz and 128KB, 4MB of memory.
So, what is the "perfect Z80" for me? 32k to 128k of RAM, clock from 2 to 6MHz, serial ports (up to 38400 baud). CP/M 2.2 or 3, with VT52 terminal (for maximum WordStar 3.3 compatibility -- note that ANSI terminals cannot run SpelStar properly! -RealVT100s can be coerced),
I really don't understand the urge to "push" a Z80 to 20, 50, 100Mhz and 128KB, 4MB of memory. The fun is the lack of memory and lack of speed (for me). I have been contemplating getting an old-timey ASR-33 teletype and an old-timer cassette recorderfor the "real feeling". If I actually need to run a word processor, I *could* do most of what I need with WordStar 3.3, but I need to use Microsoft 365, Google Docs, etc. to actually collaborate with others (with a side of OpenOffice). Doesn't actually
Then you'll love good old Commodore 128 in its CP/M mode: running at 2 MHz, 128 kB, CP/M 3, Wordstar of course can be run etc. Everything as you wish.
If hardware control is really of interest, there's Arduino where the add-ons are
cheap, prolific and easier to program due to the pre-written routines, large knowledge and user base.
If hardware control is really of interest, there's Arduino where the add-ons are
cheap, prolific and easier to program due to the pre-written routines, large >> knowledge and user base.
Not only that; AmForth and Flashfort work even on little ATmega328P
(the one in Arduino Uno) just fine — and AVR's assembly language
resembles to some extent the one of 8080/Z80: http://www.avr-asm-tutorial.net/avr_en/micro_beginner/instructions.html
Hi all,Ideal for me would be if it doesn't use any chip more powerful than a Z80, and, of course only one Z80.
please describe, in your opinion, which should be the hardware characteristics of an "ideal" standalone Z80-based retro computer!
By hardware characteristics, I mean: processor speed, RAM/EPROM size, storage media (type, storage capacity), keyboard interface, video screen interface, etc.
thanks,
Ladislau
Ideal for me would be if it doesn't use any chip more powerful than a
Z80, and, of course only one Z80.
Let's not forget the Z80 itself was a new processor
built upon an old design and became popular for that reason.
Let's not forget the Z80 itself was a new processor
built upon an old design and became popular for that reason.
Let's not forget the Z80 itself was a new processor
built upon an old design and became popular for that reason.
Yes, no, kinda, maybe?
8080 compatibility definitely helped on the software side,
running CP/M and such.
But the Z80's hardware was tremendously easier to use,
almost like silicon-chip Lego, thus becoming the favorite for embedded systems
such as "smart modems", SCSI controllers, terminal servers.
In a way, the Z80 peripherals were "the tail wagging the dog"
because they were so popular, particularly the SIO dual-channel serial I/O chips.
Z80 hardware features:
+5 volts only, no +/- 12v
single phase clock: no special clock generator required
Z80 native peripheral chips self-arbitrated DMA and vectored interrupts via daisy-chain.
No interrupt controller required.
built in dram refresh cycle, making RAM interfacing easier.
The Z80 signals were so direct and easy to use
that they formed the basis of the STD bus (which was later extended).
I/O address space was separate from the 64k memory address space
due to IN, OUT instructions asserting the /IORQ signal instead of /MREQ
and other things :-)
On 7/09/2023 1:50 pm, Jeff Jonas wrote:
Let's not forget the Z80 itself was a new processor
built upon an old design and became popular for that reason.
Yes, no, kinda, maybe?
8080 compatibility definitely helped on the software side,
running CP/M and such.
But the Z80's hardware was tremendously easier to use,
almost like silicon-chip Lego, thus becoming the favorite for embedded systems
such as "smart modems", SCSI controllers, terminal servers.
In a way, the Z80 peripherals were "the tail wagging the dog"
because they were so popular, particularly the SIO dual-channel serial I/O chips.
Z80 hardware features:
+5 volts only, no +/- 12v
single phase clock: no special clock generator required
Z80 native peripheral chips self-arbitrated DMA and vectored interrupts via daisy-chain.
No interrupt controller required.
built in dram refresh cycle, making RAM interfacing easier.
The Z80 signals were so direct and easy to use
that they formed the basis of the STD bus (which was later extended).
I/O address space was separate from the 64k memory address space
due to IN, OUT instructions asserting the /IORQ signal instead of /MREQ
and other things :-)
I worked in telecom. Equipment originating from Europe (Siemens) tended to use the 8085 while the Japanese (Ando) used the Z80. So not a great deal
of difference between them in that market. Unlike Zilog, Intel appears
to have lost interest in the 8080 line. I wasn't aware the 8085's 'undoc' instructions were actually new instructions which Intel, in their wisdom, chose to disown.
What about Steve Ciarcia's (sp?) SB180 single board computer as
featured in Byte Magazine (before it's demise). He had a column
called "Circuit Cellar", I think.
As I recall, though, it used a Hitachi chip of some sort rather than a
Z80.
What about Steve Ciarcia's (sp?) SB180 single board computer as featured in Byte Magazine (before it's demise). He had a column called "Circuit
Cellar", I think.
On Thursday, September 7, 2023 at 9:03:26 AM UTC-7, pH wrote: ....<snip>......
What about Steve Ciarcia's (sp?) SB180 single board computer as featured in >> Byte Magazine (before it's demise). He had a column called "Circuit
Cellar", I think.
Correct on all counts! The Ciarcia SBC was based on the Hitachi Z180.
IMO, the Z180 is not a good example of a "z80 based" CPU. It broke the
I/O opcodes that used the content of the C register to address ports.
There was a good reason for that (too detailed to go into here), but unfortunately those opcodes were used in a lot of legacy Z80 applications.
It was a nifty way to address multiple I/O ports just by changing the
content of C. In order to run those old Z80 applications on a Z180, the parts of the code that used those opcodes had to be rewritten.
The claim was that the Z180 was 100% binary code compatible with the Z80
was obviously not true, and that might have been a factor in the lack of popularity of that CPU? It certainly never achieved the same level of acceptance as the venerable Z80! BTW, that same "glitch" might exist in
the eZ80 as well. I just don't know.
Roger
pH <[email protected]> writes:
What about Steve Ciarcia's (sp?) SB180 single board computer as
featured in Byte Magazine (before it's demise). He had a column
called "Circuit Cellar", I think.
As I recall, though, it used a Hitachi chip of some sort rather than a
Z80.
This one?
<https://archive.org/details/BYTE_Vol_10-09_1985-09_10th_Anniversary_Issue>
...BTW, that same "glitch" might exist in the eZ80 as well. I just don't know.
The claim was that the Z180 was 100% binary code compatible with the Z80 was obviously not true, and that might have been a factor in the lack of popularity of that CPU? It certainly never achieved the same level of acceptance as the venerable Z80!
I wonder if any of those got out into the real world and used much.
pH
On Friday, September 8, 2023 at 4:31:58 PM UTC-5, pH wrote:rediscovered it during a clearout last year but I wasn't able to find
I wonder if any of those got out into the real world and used much.I have one of those blank boards that I bought back in the day. I
pH
On 2023-09-19, [email protected] <[email protected]> wrote:
On Friday, September 8, 2023 at 4:31:58 PM UTC-5, pH wrote:
I have one of those blank boards that I bought back in the day. Irediscovered it during a clearout last year but I wasn't able to find
the EPROM code for download anywhere, so it sits in my PCB drawer unused. I 'd love to get it up and running though.
Maybe one of the hobby sites can write an eprom for you.
Here's a website that talks about it.
http://dunfield.classiccmp.org/mmint/
Maybe he'll pull his eprom and copy it for you.
pH
On Tuesday, September 19, 2023 at 11:04:28 PM UTC-4, pH wrote:
On 2023-09-19, [email protected] <[email protected]> wrote:
On Friday, September 8, 2023 at 4:31:58 PM UTC-5, pH wrote:
I have one of those blank boards that I bought back in the day. Irediscovered it during a clearout last year but I wasn't able to find
the EPROM code for download anywhere, so it sits in my PCB drawer unused. I
'd love to get it up and running though.
Maybe one of the hobby sites can write an eprom for you.
Here's a website that talks about it.
http://dunfield.classiccmp.org/mmint/
Maybe he'll pull his eprom and copy it for you.
pHhttp://cini.classiccmp.org/systems.htm
Scroll down to "SB180/COMM180" and check out "Monitor source code (asm)": http://cini.classiccmp.org/files/mon20.z80
Would a 20MHZ z80 (or more) be able to play Zmachine games (z5 and z8 version)
with enough speed? I think the 6502 on the C64 with a REU it's able to play >> Z5 games with a few seconds delay and Z8 games run very slow.
You know, the interpreter to run Infocom games, but there are several
"amateur" (not so amateur since the 1993's game 'Curses!'). games to try.
Bear in mind Z3 games will run fine in any 8bit machine, but for Z8
games a 286.386, or 68k machine it's expected.
I'm not an expert on Z machine games... can you give me a hint about where to download some v5 or v8 games for Z80?
I suppose no color/graphics is required...
I have a 25MHz Z80 machine (Z80ALL), the screen has 64x48, it is VT52 compatible, let's give it a try :)
Ladislau
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