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Author Topic: z80 assembly  (Read 5649 times)

Offline MrPlow

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z80 assembly
« on: 2014-Sep-26 »
Forgot how much fun it is code something in assembly...

I basically did a basic little maze rogue thingy and using z80 to draw screen UDGs from map data.

Nothing earth-shattering but still fun!
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Offline bigsofty

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Re: z80 assembly
« Reply #1 on: 2014-Sep-26 »
Loved Z80, probably could not code anything in it nowadays but it loved it for its clarity back in the day. MC68000 is a close second in my book too.
Cheers,

Ian.

“It is practically impossible to teach good programming style to students that have had prior exposure to BASIC.  As potential programmers, they are mentally mutilated beyond hope of regeneration.”
(E. W. Dijkstra)

Offline Marmor

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Re: z80 assembly
« Reply #2 on: 2014-Sep-26 »
Ld a,a

Long long ago

Offline Moru

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Re: z80 assembly
« Reply #3 on: 2014-Sep-26 »
Yes, I loved 68k too. Made a screensaver that actually accellerated the computer with about 30%. Grafic card shared memory and bus with CPU on the Atari and when the Falcon came, the high-res, high-color modes really made the computer crawl :-)

Still miss the instant resolution change possible at that time. How come it takes 1-2 seconds to switch resolution on PC hardware with CPU and grafic cards so much faster than an 8 MHz 16/32-bit computer?

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Re: z80 assembly
« Reply #4 on: 2014-Sep-26 »
Never tried Z80 - 6510 and ARM was my assembler systems of choice.

Offline Ian Price

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Re: z80 assembly
« Reply #5 on: 2014-Sep-26 »
I used Z80 BITD on my Amstrad CPC after I worked out that Locomotive BASIC (while excellent) was very slow. I couldn't tell you a single thing about it now (Z80 or CPC BASIC!). Same as all the other languages I've used over the years; I move on and quickly forget everything. It's strange because when I'm using any language, I know it pretty intimately. I'm sure it's all in my brain somewhere, and I do often think about coding something for the CPC again, but I just don't have the time to really focus on re-learning that stuff again. Unfortunately. :( I'd love to see AquaVenture and B'lox! on CPC one day...
I came. I saw. I played.

Offline Sokurah

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Re: z80 assembly
« Reply #6 on: 2014-Sep-27 »
Having made 3 games in Z80 (and two more almost finished) I can only agree that it's a hugely rewarding language to code in. So much fun.
I also played around with 68000 back when I had an Amiga and would love to make a game for that processor some time. The big problem is just finding the time to do it.  :doubt:
Website: Tardis remakes / Mostly remakes of Arcade and ZX Spectrum games. All freeware. :-)
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Offline Paul Smith

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Re: z80 assembly
« Reply #7 on: 2014-Sep-27 »
Started learning Z80 on my CPC Plus using HiSoft DevPac which came free on amstrad action.

But get exited when Longshot from Logon Systems released this code

org &8000
 di
 ld b,&bc
ld hl,sequence
ld e,17
.seq
ld a,(hl)
out (c),a
inc hl
dec e
jr nz,seq
ei
ret
.sequence
defb &ff,&00,&ff,&77,&b3,&51,&a8,&d4,&62,&39,&9c,&46,&2b,&15,&8a,&cd,&ee

Which unlocks the unlockable  Asic Chip.

Got a 386sx 25/ Borland Turbo Assembler and a teach yourself x86.
Wouldn't know where to start now, but have used the knowledge to reverse/patch exe,s
Amstrad CPC 6128, ATARI STE.
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Offline MrPlow

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Re: z80 assembly
« Reply #8 on: 2014-Sep-27 »
I am very surprised how much I can recall of Sinclair BASIC and system variable poke locations...

I did some z80 on computer and electronics course (many years ago) where we used pluggable PCB boards,resistors,LEDs and z80 chips and coded them directly...also good fun...like adult Lego.
 
« Last Edit: 2014-Sep-27 by MrPlow »
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Offline mentalthink

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Re: z80 assembly
« Reply #9 on: 2014-Sep-27 »
Yes just I'm learning in some free time the Z80 ASM for the Amstrad Cpc, really it's very very fun and easy, I rebember when I was a child, I ear something about ASM, but seems in those times this was for very MACHO men  :D :D

Now looking some webs and reading a very very good trining of Amstrad Semanal, a 80's Magazine in Spain really it's easy and most inAmstrad, it's have a firmware really really powerfull, basically it's something similar to GLbasic, put a bit of code and call to functions( the firmware routines) and you can do very interesting things...


Offline bigsofty

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Re: z80 assembly
« Reply #10 on: 2014-Sep-29 »
I must admit that I miss the old 8/16 bit computer fixed systems. 2 books stand out that you just dont see today...

The Amstrad CPC Firmware Manual

It had a everything from BIOS calls to circuit diagrams of the main board. You could build your own CPC is was so detailed.

The Complete Spectrum ROM Disassembly
( ftp://ftp.worldofspectrum.org/pub/sinclair/books/CompleteSpectrumROMDisassemblyThe.pdf ).

This was a disassembly of the ZX Spectrum BIOS, very handy to see how ZX things worked and how a BIOS actually works.

This kind of openness allows a programmer to get to know the machine at a level you just dont see any-more. Which is a pity, because it was great fun.
Cheers,

Ian.

“It is practically impossible to teach good programming style to students that have had prior exposure to BASIC.  As potential programmers, they are mentally mutilated beyond hope of regeneration.”
(E. W. Dijkstra)

Offline Paul Smith

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Re: z80 assembly
« Reply #11 on: 2014-Sep-29 »
Used the amstrad manual to add a tape drive as the connection was removed in 6128plus model, also made the Atari St mono sound stereo by cutting the YM output track short on the board and soldering a 3.5mm jack to it.worked great for chip sound but distorted on digi samples.
Amstrad CPC 6128, ATARI STE.
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Offline mentalthink

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Re: z80 assembly
« Reply #12 on: 2014-Sep-30 »
bigsofty if you need the Firmware ,about Amstrad is this...

If you want conserve your eyes you can download a .pdf
http://www.cantrell.org.uk/david/tech/cpc/cpc-firmware/

About done a Amstrad from zero with the electrnic scheme it's practically impossible, because Amstrad have some "custom chips" like the video Chip, this it's impossible to get today , but really find an Amstrad or Spectrum the cost only it's between 15 to 60 Euros...

 In spectrum happends something similar you can't find the ULA, was a custom chip for Sinclair, but some very smart guys done inverse enginenering of this chp, and you can done a clone of a sinclair, in fact I have one, but at today I can't do works (Come short circuit in the PCB heat a lot some components)

Sure Hark0 can comment something , he's collaborating in an Spectrum running into a FPGA's, it's like emulation but better, the sysitem it's really cool you can put the 3 models of spectrum , with a Hard drive (SD memory) and the size it's something like a Raspberry or more little .... the good point the device it's cheaper and do the same like a real Spectrum.


Offline bigsofty

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Re: z80 assembly
« Reply #13 on: 2014-Oct-01 »
Thanks Mentalthink but I still have my original CPC Firmware Manual on my shelf. Looking at the online Cantrell version its got a lot of stuff missing, no diagrams for example, about 60 pages, where as my original firmare manual is over 300 pages.  :S

Well done on your hardware mods Paul. Tough decision on the ST though, better chip-tunes or mod music, I'd go for the ST chip-tunes every time IMHO.
Cheers,

Ian.

“It is practically impossible to teach good programming style to students that have had prior exposure to BASIC.  As potential programmers, they are mentally mutilated beyond hope of regeneration.”
(E. W. Dijkstra)

Offline Paul Smith

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Re: z80 assembly
« Reply #14 on: 2014-Oct-01 »
Quartet was the only good mod style player for the Atari St i can remember,most games didnt use samples. Most demos had one digi screen per disc., however my quick fix was putting the sound jack into the amp and pulling it out slightly causing the left and right channels to mix. I I was probably about 14 at the time cutting components out of working and broken electrical things.
Even made a speech synthesiser in school from a magazine diagram. Sending data to the SPO256 chip using the OUT command. chip stolen from my sister speak and spell.

loved them tinkering days,
Amstrad CPC 6128, ATARI STE.
Acer  SW5-173 & AMD FX 8350/1050Ti