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Zilog (re-)introduces the Z80
The Finn writes "Zilog has introduced an update to their now infamous Z80 line of processors. The new eZ80 ``[...]is one of the fastest 8-bit CPUs available today, executing code 4 times faster than a standard Z80 operating at the same clock speed.'' The last Z80-based computer I actually used for any length of time was a Xerox 820-II CP/M box, but the Z80 continues to live on in all kinds of embedded applications. "
Yes, there are several programs that accomplish this. There's Telnet 83 for the TI-83 for one... then there's FTerm for the TI-92. There's others that I can't locate at the moment. But to sum up, yes it is possible already, but in theory this new eZ80 could make it more possible :)
Adam Berlinsky-Schine
Actually the MC68000 is more of a 32 bit chip. The data bus is only 16 bits wide, and it uses 24 bit addressing (IIRC), but all the registers are 32 bits wide.
Zilog's greatest product line.
From the little Z8's to the z180's, et. al.
Those things are great. I have both a TI-85 and a TI-86. I was really happy to be able to recommend those great ZWorld contollers at a job a while back. An absolute dream to work with. I recommend them all over the place now.
Man, they were pretty successful in milking them. I have their 1997 Master Selection Guide here and it's full of really neat app-specific chips for PDA's, set-top boxes, data communications, DSP (including voice), and so on.
Zilog were really smart with the Z80. Good for them. And they did it without all that shameless marketing certain-other-processor-companies are known for.
No, only the TI-89, TI-92, and TI-92+ Calculators use 68K processors. All the others (for our sake let's say TI-82 through TI-86) use a Z80 processor. And whoever said they wanted a TI-93 - save up all you want but the calculator doesn't exist :) (TI-92+ maybe?)
Adam Berlinsky-Schine
Sure do remember it, my first consulting job was Z80 assembly, an ultrasound probe to measure depth of human eyes. The "Klingon" instructions, as I remember calling them back then, were quite useful indeed. I'd take Z80 over 8085 any day.
For my money though, nothing beats an 8032 for a *simple* 8-bit embedded microcontroller. Named bits, quasi-bidirectional ports and a multiply and divide are just too useful, not to mention cycle counting is far easier.
Once you've seen ONE assembly, they are all the same, but you need to start humble, and the Z80 was just a great start for me.
:-)* However, it is really easy to program and I've seen absolute beginners to any type of programming eat into it *really* quickly.
Ever seen PIC assembly? Some things are the same, but some of it is way off the beaten track.
There's an unconditional jump called GOTO.
There's no real conditional jump...
BTFSC/BTFSS - Bit Test F, Skip if Clear/Skip if Set. It basically skips the next line if a specific bit is clear or set. Make the next line a GOTO and you essentially have a conditional jump.
SWAPF - Swap nybbles in F. Interesting.... especially for a RISC chip...
If you're used to other architectures, the PIC looks, well, wierd. The first thing most people notice is the lack of instructions that begin with 'J'
Of course, the Z80 is great for getting into more "traditional" architechtures. Now with TI explicitly enabling asm programming on their calculators (without having to use memory dumps) a lot of young ones are delving right into it.
And next year, intel will be releasing the 8088, renamed "Merced". . .
"The number of suckers born each minute doubles every 18 months."
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
Better yet, will the embryos behind the counter at Radio Shack be able to tell me what a TRS-80 even is?
Inquiring minds want to know!
I want one of these in my ti-86. Then i'd be able to watch it find roots of a 30 degree polynomial. And it would be great for games.
Seriously though, it does say it's code compatible with the original Z80. Would it be too hard for some calculator hackers to "upgrade" a graphing calculator?
Also, is the tcp/ip stack built into the chip? If so, could I browse the internet on my calc? You would just need a ppp implementation and a 9600 baud modem....
Isn't the Z80 the same processor used in lego mindstorms? If so... I'm thinking there's going to be a few adventerous(sp?) souls that are going to opt for a brain transplant.
--
The all-knowing, all-seeing DonkPunch looks into his crystal ball and sees the responses to this story:
"Let's port Linux to it"
"Let's make a Beowulf cluster"
"I remember using a Z80...."
"My company is developing embedded software for Z80s...."
"Why? It's an 8-bit processor! Who uses that anymore?"
"First Post"
Save the whales. Feed the hungry. Free the mallocs.
Here's a bunch of Z80/CPM emulators for all major platforms, kindly grouped together in one elegantly uncluttered site.
Eat 'em up!
**>>BELCH
the new z-80 is a 'good thing'. here's why:
1) This paves the way for new texas instruments graphing calculators. (many run on z80s. it would be rather simple, according to zilog, to replace them with eZ80's.)
2) i think that there's money to be made in a z80 based business computer. you could make the hardware for real cheap, and then custom tailor an incredibly efficient operating system, and business apps. the Z80 is how many decades old? Z80 programmers know that chip incredibly well by now, so they can get their code as efficient as possible. if all of the hardware was uniform, (like playstations) you wouldn't need to bloat the o/s with support for obscure parts that almost nobody has. also, being that the o/s code is completely new, you wouldn't need legacy support! I'm telling you, Z80 computers, while not perfect for gaming, could be made to outrun a PIII running win98 any day in business apps. for much less!
I remember the good 'ole days of Cromemco and the Cromix operating system. Some of the machines had a Z80 and a Motorola 6800 DPU. The Z80 ran backward comtability programs andthe 6800 ran the OS.
My dad and I hooked up an A-to-D board and controlled an RC car in the garage. Talk about your open standards. It schematics, replacement component #'s (not part #'s, component), journals about the hardware/software similar to the linux community or LJ ("TechTips" it was called).
It had the original Star Trek and Adventure, I blasted banner pages at all of my dads employees, and sat dumb-founded by the high-speed dot matrix printer with the gree-bar. It rattle back and forth until it walked accross the room. I can remember having to build a sound absorbing box because nobody could hear the phone over the top of it.
I guess my favorite thing about the system was being able to fry a serial port controller in the morning and have it repaired in an hour with off the shelf components.
This is the same reason why my coffeemaker doesn't have a pIII-500 in it.
My coffemaker has a PIII-500 in it - for a heating element!
--"In dreams begin responsibilities" - Delmore Schwartz
Oh yeah, glad I wasn't the only one to do that! My HS bought a TRS-80 MIII back in '81 and once I reached the limit of what I could do with basic, I then moved on to Z80 assembler because that's all else there was.
Then I got to Purdue where I learned 'the true nature of the Force' with OS/360 BAL. Thank god they got a vax 11-780 the next year or I might have given up on programming as a career (I eventually did anyway, but not because of IBM mainframe assembly.
By the time I graduated in '86 they had IBM XT's but I never had much of a chance to program assembler on those.
Hmph. Go find some documentation on the Saturn CPU used in the HP-28/48/49 calculators. It makes the Z-80 look like a 68000 from that aspect.
(surround the LD B,0 with a PUSH/POP if needed)?instructions that don't work well together (it's a pain to add an 8bit counter to a 16bit total)
You mean like:
In general, the Z-80 was simple to learn and use, from both the hardware and software perspectives. I'm happy to see it still around. Some things I did with it in 1980 (say, a programmable sequence tone generator - in 4 chips and no RAM) were next to impossiblt to do as well or as cheaply for years afterward.
--
Disinfect the GNU General Public Virus!
I remeber the 820, almost bought one.
It's 8 inch drive was compatable with an
IBM key to disk machine, don't remember the
number. Anyway, I wrote a program to emulate the
key to disk machine and it worked. Just didn't
have the cash to buy it at the time.
My wife wanted a setup like that to replace
her keypunch machine. We still have it.
Maybe I should ebay the keypunch machine!
Anyone used Sinclair Spectrum around here?
Yes! Yes! My first computer was a Spectrum+. A few weeks ago, I was looking round a computer shop in London that specializes in retro hardware and software. They had a second-hand Spectrum+. I got a bit choked up just looking at the thing. If carrying it home hadn't been a problem, I'd have bought the thing on the spot.
I remember there was a group at the Cluj Computing Center in Romania, who had found something like 26 hidden, not documented but working instructions in the Z80.
Including the splittable index registers used in Spectrum protection systems like Speedlock?
On the other hand, the larger memory space and (seemingly built-in?) TCP/IP stack offers the opportunity to build a "RetroWeb Server." Note that ZSDOS, a ZCPR variant, is now available under the GPL.
The possibilities are immense, I mean, minscule. A complete web server could probably fit in a volume of 2 cubic inches...
If you're not part of the solution, you're part of the precipitate.
The original Sega console system, the Sega Master system was powered by the z80. Back in the day that was the system to own. It didn't have tons of games but the graphics ruled the NES. They even made a converter for the Genesis that had a z80 in it for backwards Master System compatability. Great old system, still wouldn't trade my Dreamcast for one though.
Pete
I can see through time - Lisa Simpson
The sole purpose of the Internet is to get porn and bomb making plans into the hands of children.
It was recently announced that Amiga would incorporate these chips into their new machine designs.
I couldn't agree more. It had several cool features. Bit testing instructions. Two complete sets of general purpose registers (EX and EXX instructions, remember?). More on-chip integration than most (the refresh register for dynamic memories). It had a vectored interrupt system. All of this and full instruction set compatibility with the much less capable 8080A (and its later incarnation, the 8085).
My Dad was an EE who worked for Control Data and I was a pimply-faced teenager who loved programming. We homebrewed an S-100 bus based Z80A computer between 1975 and 1978 (so it took us awhile!). I wrote the BIOS for our hardware for CP/M 1.2 (later 1.4 and 2.0 also) in Z80 assembler.
We also did a number of embedded projects with the chip. The z80 had features that were a dream for embedded programmers. In our case, we made a simulated event-driven machine by polling during a timer interrupt. We made use of the aforementioned dual register sets. Instead of the normal chaos of stack frame switching (and hoping you do it right) we just said the prime register set is for the interrupt service routine and the regular set is for the normal operation. On entry to the ISR, just do an EXX and on exit do another one. No disruption of the "application" whatsoever, plus interrupt latency is unbeliveably small (no external bus cycles at ALL!)
I did and do love this chip. I know it can't really cut it as a general purpose computer CPU anymore, but some of those apps that were built on and ran on this hardware (WordStar, etc.) did quite a bit. They're not that much weaker than Word and they would run in less than 64k on machines clocked at from 2 to 6 MHz. How well would Word do?
It is great to see this processor still alive and kicking.
The Z80 is an awesome processor. It's great for beginners at assembly programing - it has a nice, simple, clean architecture and instruction set. It has thousands of uses in embedded applications and is plenty fast for most of them. The Z80 is available for $1.50 a piece (at Fry's) and even takes very little power and produces very little heat.
Some time back I wrote a patch for a public-domain Z80 assembler to let you also use the intel opcodes (with a pseudo-op to switch between them), to simplify some porting of an 8080 ROM monitor/debugger. The Z80 was "trailing edge" technology at the time, so I didn't publish them. Maybe I ought to now. (If I can find 'em. B-) )
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
The computer I had was a CPC 6128 and Gee, did I just love this computer? I even made myself an 8Kb memory extension to write my own boot code that you would call like |Eg0r and stuff from the basic prompt, brilliant!
Anyway, I still do think that in order to learn assembly properly, all you need is a processor you understand everything about, from registers to conditional jumps and so on... Man, x86s are just too complicated to program :-need all those instructions? I know it's cool to have instructions that would take you several op codes to get the same result, but when you learn, all you need is the bare minimum :-)
Anyway, what I learned about the Z80 around when I was a 14 year old teenage kid thinking 'Gee, 8K? I'll NEVER need that much space' :-) helped me with the motorola 68K (both at school and on my Amiga) and then with the TMS320C30, C50, C40 DSPs...
Once you've seen ONE assembly, they are all the same, but you need to start humble, and the Z80 was just a great start for me.
Of course, this is all redundant now, because VLIW is not something you code by hand, but having some knowledge being able to code a microcontroller is never lost!
See Imaging tutorials 1 and 2 to get some ideas of what can be done both in C, assembly and MMX!
So, what do you guys have learned assembly on?
---
"Hasta la victoria siempre!" El Comandante
I'm not sure about Legos, but the Z80 is used in industrial controllers and has proven very reliable. I see the Z80 pop up in various products over time. The Z80 may never die.
Here are some Z80 source code for projects done back in college, including GUI with mouse, etc.
Hitachi did a couple of 'extended' variants on the Zilog Z-80 as well. The Hitachi HD64180 is a souped-up Zilog Z-80, and later reissued as the Zilog Z-180. Includes a simple two-segment MMU which allows for access to greater than 64K, several new instructions, and a whole lot of internal special-purpose memory-mapped registers that control things like the on-board serial ports. A great chip for embedded work; I've been brushing up on Z-80 assembly code that I used on an old friend's TRS-80 model I years ago, because we found one of these as a controller chip inside a high-end VCR.
Hitachi has done this sort of thing before; the Hitachi 6309 is essentially a souped-up Motorola 6809, as many of the old TRS-80 Coco fans know...
-- Bryan Feir
What many of you don't realize is the importants of the statement "Synthesizable core". That means that I can get the VHDL description of the device, and drop it into an FPGA or ASIC (field programmable gate array and application specific integratted circuit) and make a single-chip solution to some embedded problem. Who would buy the actual silicon from Zilog? But give me a small, simple core in my ASIC and I'll be a happy man.
BTW, I too learned my assembly on a Z80. I learned real quick what happens when an ISR takes too long by writing code to blink the screen on a TRS-80 from interrupt, a lesson that I have carried forward into my years as a professional embedded software designer.
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