Blast from the past... Z80!

On a sunny day (Fri, 30 Jan 2009 07:18:08 -0800) it happened John Larkin wrote in :

No wonder you hate programming. You simply never programmed a good processor.

The Z80 is a very very very nice processor to work with.

PSoC has been around for awhile, although Cypress occasionally re-targets it to different markets... such as their current push into using it for touch sensors.

The analog bits are pretty cool. The CPU they include is a rather ugly, low-performance no-frills design. But hey, it does get the job done, I suppose...

In article , snipped-for-privacy@yahoo.com says...>

If you enjoy moving data from here to there and back. I'm with John. Yuck.

In article , snipped-for-privacy@yahoo.com says...>

The *NEW* stuff (PSoC-III, IIRC) looks like it'll finally be useful, is my point.

Have CPU. Planning on adding FPGA. A PSoC-III looks like it'll make the design almost entirely programmable. ;-)

Hear, Hear! I also enjoyed working with the 6502. The 8051 isn't bad when you get used to its foibles and learn how to use the timer. ;-)

But the first time I worked with the 68HC11 I fell in love with its timer system. :-)

Cheers! Rich

Ah, gotcha. I did a bit of Googling, and apparently there is some PSOC 3 hardware out (if you know the right people) but software is still being developed and hasn't been released yet? I'll have to keep on top of it.

Now that is going to kick some ass! A sales rep already mentioned an ARM core in a Xilinx device.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
                     "If it doesn\'t fit, use a bigger hammer!"
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In article , snipped-for-privacy@yahoo.com says...>

The Cypress rep was here last week with the Avenet rep, doing their dog and pony thing. They said there was hardware available, though samples and software wouldn't really be available in the spring. I said I wanted to be on their list when I could actually play with the software. Maybe April.

On a sunny day (Fri, 30 Jan 2009 12:57:20 -0600) it happened krw wrote in :

Sorry I do not get that. Would you care to elaborate on 'moving data from here to there'?

On a sunny day (Fri, 30 Jan 2009 19:26:02 GMT) it happened Rich Grise wrote in :

I wrote a small assembler for the 8051, and the 8052AH BASIC.

In the sense that that assembler also could generate data statements tha tyou could then include in that BASIC. And I still have a small 8049 development system / programmer I designed. But I never used that chip much. Never used the 68HC11 either.

grml:~# a52

8052 ASSEMBLER VERS. 1.0 copyright 28-12-1988 Panteltje.

ABORTED NO SOURCE FILE SPECIFIED#

LOL I think this asembler is not very good, and largely untested, but at that time the Intel one was about a 1000$ or so.

In article , snipped-for-privacy@yahoo.com says...>

95% of the instructions are moves (load/store register).

So, all we do any more is connect boxes and hack code.

Depressing.

John

PDP-8 PDP-11

6800 6802 6803 HC08 x86 68332

and one CPU I designed, which was admittedly sort of a dog, with a 20 KHz clock rate.

I loved the PDP-11, for its beautiful instruction set symmetry; it just begged you to use stacks and structures. The instruction set was so logical that most programmers quickly learned to convert opcodes to octal in their heads.

MOVB @R2, -(SP) is 111246. The digits are: byte, move, indirect, reg2, autodecrement, stack pointer=r6. And I haven't touched one in 20 years.

There was also the "land mine" instruction

MOV -(PC), -(PC) 014747

which copies itself one location below itself and executes that copy. The PC is just another register. NEG PC is perfectly legal.

The 68332 isn't as symmetric, but it has sixteen 32-bit registers and some very nice math ops, like 64/32 divide with remainder, which does

64-bit-binary to decimal-ascii conversions at blinding speed. Tricks like relocating code into cpu ram (poor man's cache) for execution speedup are easy.

Coldfire or ARM will be next.

8-bit machines are annoying. Too many add-with-carry loops, limited branch ranges, paging/mapping to get decent address space, too few registers, no or rotten indexing. Transistors are almost free nowadays.

John

Yeah, sort of a kluged 8008.

John

:

A lot better than an 8008. A little bit better than an 8080/5. In that vintage I liked the NSC PACE better.

it

If you consider VHDL to be "code". I still see hardware when I'm doing it. Treating VHDL as a programming language rather than more of a markup language creates junk.

Actually, I rather like being in control of the whole shebang (though I don't do code anymore).

Seems to be going okay for me, though it's annoying how everything goes so damned slowly...

ld a,(counter) ; two microseconds add b ; one microsecond ld (counter),a ; two microseconds ; ...

And with only the accumulator to do any reasonable math (INC and DEC at least are available on other registers), you're always loading accumulator-memory and memory-accumulator stuff. It takes three operations to add memory!

Now 8086 on the other hand, add dx,[bp+si+06] Ohh yeah baby...indirect offset addressing modes...droool... Okay, so effective addressing calculations went snail slow on the 8086 too, it's stuffed full of microcode. The above EA calcuation is supposed to take 12 clock cycles, and I don't even remember if those are *clock* cycles (8MHz in the faster 8086, woo!) or bus cycles (divide by 4 or so). Still, the individual operations are so much more powerful. No wonder it was chosen for the very first "PC" (the PC-XT, that is). The thing is a bear to wire up though, I don't think I even have enough breadboard space to put one together, and that's assuming I had the clock and bus controller chips, which I don't. That's one thing the Z80 has, ease of use.

Tim

On a sunny day (Fri, 30 Jan 2009 13:40:18 -0800) it happened John Larkin wrote in :

See, I was right, no experience with Z80, completely frustrated because of all that other primitive stuff. :-)

If you had ever looked at the Z80, you would know it has 16 bit addressing, It has beautiful index registers, that allow offset and bit operations on index

• or - offset: set 3,(ix-53) Nice I/O functions to send memory block to peripherals: otir Build in refresh logic Much more stuff to make programming fun.

The Z80 was actually an improved version of the Intel 8080, with many more instructions, in the sense that it is 100% compatible with it and will run 8080 code. I have used the 8080 assembler with it.

On a sunny day (Fri, 30 Jan 2009 15:01:44 -0600) it happened krw wrote in :

So, that is no problem? It is up to the programmer how he handles data.