My first ASM
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Haven't written any in over 40 years, since writing it on a PDP-10 while at university. But it definitely has a charm to it.
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The fox knows many things, but the hedgehog knows one big thing.Greg Utas wrote:
Haven't written any in over 40 years, since writing it on a PDP-10 while at university. But it definitely has a charm to it.
Back in my day, we used to carve our code with a hammer and chisle on stone punch cards.
Nothing succeeds like a budgie without teeth.
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Greg Utas wrote:
Haven't written any in over 40 years, since writing it on a PDP-10 while at university. But it definitely has a charm to it.
Back in my day, we used to carve our code with a hammer and chisle on stone punch cards.
Nothing succeeds like a budgie without teeth.
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Greg Utas wrote:
Haven't written any in over 40 years, since writing it on a PDP-10 while at university. But it definitely has a charm to it.
Back in my day, we used to carve our code with a hammer and chisle on stone punch cards.
Nothing succeeds like a budgie without teeth.
Yes, that led to the very first method: CRN (Convert Roman Numerals).
If you can keep your head while those about you are losing theirs, perhaps you don't understand the situation.
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But does it cover 6502?
"The only place where Success comes before Work is in the dictionary." Vidal Sassoon, 1928 - 2012
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Indeed. My first brush with assembler was writing little games etc in Z80 code on a self-built NASCOM1 computer. My first major contract was porting MSDOS 1.25 to an IBM PC Clone. The disk drivers etc were all written in 8086 assembler. I can still see the thousands of pages of printed listing that I had to work on! (Filled with useless comments of the sort: "-- add 23 to AX")
Mike Winiberg wrote:
My first major contract was porting MSDOS 1.25 to an IBM PC Clone
Wow! I wouldn't have even known where to start. How did you discover the details back then? Very difficult, very few books if any on stuff. Maybe the old Peter Norton book. Really interesting.:thumbsup:
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I started out with Z80 and 6809 machine code, there were no assemblers available to me back then. I wrote my first code like this around 40 years ago which was a ROM extension for Basic to control sound and speech hardware. Thinking back and comparing to the likes of modern assemblers or VS I have no idea how I managed it!
Private Dobbs wrote:
Thinking back and comparing to the likes of modern assemblers or VS I have no idea how I managed it!
Maybe you read Dr. Dobbs Journal? :) I just couldn't help notice that you are Private Dobbs. You wouldn't happen to be a doctor in your spare time, would you? :laugh: There was so little documentation back then. It's amazing that devs were able to do the things they did. Very cool story.
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When I wrote my first assembler program 25+years ago, I was so proud of being able to speak the computer's "native" language ! Like you could interact directly with its perception of things without the filters of the high level languages.
Rage wrote:
When I wrote my first assembler program 25+years ago, I was so proud of being able to speak the computer's "native" language
Yeah I always remember Bill Gates quote about when they were controlling a PDP-8 or PDP-11 from his school. Then they were in high school and working with a large corporation and writing code for them. He said something like, "It was amazing that we were high school students and we were able to control this machine that was worth millions $$$ that very few adults could even understand and control." It's very true.
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Check out Easy 6502 by skilldrick[^] I found this a great resource. And after watching the first episode of this series: https://www.youtube.com/watch?v=qJgsuQoy9bc[^] I realised I wanted to make my own emulator. Rather than follow the video series blindly I decided to do it in JavaScript and not follow the videos. This presented some challenges as JS doesn’t have Byte/Word types so that has to be managed manually. I’ve been trying to learn ASM for Gameboy, megadrive, z80, but didn’t get very far. Reverse engineering the code allowed me to properly understand each instruction and I am learning ASM as I go. Here is my WIP project: GitHub - gcoulby/MOS6502: CPD project to learning MOS6502 assembly language, which snowballed into reverse engineering the CPU[^]
I grew up on 6502 - instead of cereals and milk... :-D
"The only place where Success comes before Work is in the dictionary." Vidal Sassoon, 1928 - 2012
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Haven't written any in over 40 years, since writing it on a PDP-10 while at university. But it definitely has a charm to it.
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The fox knows many things, but the hedgehog knows one big thing.In the 1980's I was using a PDP-11/34a in High School. I LOVED MACRO-11 Assembly Language. Basically it was C without the {}, LOL... I was running RSTS/E time sharing (32K Words of memory to support almost 30 users). RK06 Drives. Paper Terminals (Decwriter 300s I Believe, and we had 3 CRTs. One with COLOR, DEC 240?) EDT for an editor (or TECO if you were on paper. Imagine EDLIN with Type-ahead! ex$$) Curious, Gates replied to me that they were running TOPS-10 for the O/S on the PDP-10. I am still amazed by everything I was able to learn/do while in High School. My 3 Favorites: 1) I learned how to read another users keyboard buffer ("You spelled that wrong!", LOL) 2) I learned how to HALT the computer, and force my non-priv user to be a super-user! Awesome! (JFPRIV? Bit)... thanks to Michael Mayfields Book on the internals of RSTS/E book I bought with my own cash! [http://www.dmv.net/dec/pdf/rsts80inta.pdf\](http://www.dmv.net/dec/pdf/rsts80inta.pdf) WOW... I remembered JFPRIV correctly after 32 YEARS! 3) I rewrote the startup routines so the 7-10 minute startup process was done in under a minute! [I cheated. 80% of the time was changing the terminals to 300 Baud, etc. I recompiled the operating system, and modified the assembly, so the terminal settings were right for 30/33 terminals, and then only fixed the remaining 3. Even that, I rewrote in ASSEMBLY vs. BASIC PLUS 2 (BP2)] 4) I figured out how to open a tape as a non-structured file and modify it. This allowed me to copy the boot instructions from a DISK (which I learned was literally a boot loader), and write it to the tape, with a device adjustment. Making the tape, in fact, bootable. [I think I did this just after I graduated, because we did NOT have a tape drive, but I landed a job programming on PDP-11/70s] Oh, those were the days...
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I grew up on 6502 - instead of cereals and milk... :-D
"The only place where Success comes before Work is in the dictionary." Vidal Sassoon, 1928 - 2012
My first bit of tech was an NES, which did sport a version of the 6502, but there was absolutely no requirement to know what was going on inside. I only went down the path of learning 8-bit computers and assembly so I could get a better grasp at programming fundamentals. Making the emulator has been massively fun and definitely addressed the fundamentals.
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I stumbled upon this book in my APress account today and it is so nicely written that in 10 minutes I wrote my first Assembly language program and ran it. Beginning x64 Assembly Programming: From Novice to AVX Professional: Van Hoey, Jo: 9781484250754: Amazon.com: Books[^] Over the years I've looked at Assembly and tried it out a little, but it's never been easier to try than now. I have Debian running in a VirtualBox so I quickly: 1. installed nasm (Netwide assembler). 2. Installed GCC tools 3. installed make 4. created a makefile as led by the book 5. typed in the sample program 6. let the makefile build and link the program. 7. ran it. That's very cool. This author is obviously really good because he gets right to the point and explains things clearly. I am impressed and I always like to read a good book that is so well-written.
Strangely, x86/x64 is one of the few processors that I've used that I *haven't* written assembly for... Z80, 68000, VAX, ARM, various other embedded platforms, but never for any PC processors...
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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Private Dobbs wrote:
Thinking back and comparing to the likes of modern assemblers or VS I have no idea how I managed it!
Maybe you read Dr. Dobbs Journal? :) I just couldn't help notice that you are Private Dobbs. You wouldn't happen to be a doctor in your spare time, would you? :laugh: There was so little documentation back then. It's amazing that devs were able to do the things they did. Very cool story.
Alas not a doctor although at 18 I wanted to be one. However I am currently working on a medical app if that counts :)
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Mike Winiberg wrote:
My first major contract was porting MSDOS 1.25 to an IBM PC Clone
Wow! I wouldn't have even known where to start. How did you discover the details back then? Very difficult, very few books if any on stuff. Maybe the old Peter Norton book. Really interesting.:thumbsup:
You were given the sources for the relevant device drivers by Microsoft, but - as I said - the comments generally didn't give much away, so it was a lot of assembling and hardware debugging using logic analysers etc 8) Of course back in those days, MS et al published printed manuals for their software etc - you didn't have to rely on intermittent broadband connections to websites with out of date or incomplete, badly formatted docs on them!
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Strangely, x86/x64 is one of the few processors that I've used that I *haven't* written assembly for... Z80, 68000, VAX, ARM, various other embedded platforms, but never for any PC processors...
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
Stuart Dootson wrote:
Strangely, x86/x64 is one of the few processors that I've used that I haven't written assembly for..
That is interesting. I guess it makes sense too because x86/x64 are used in PCs and there are a whole host of other tools to use to develop on those platforms. Meanwhile those other ones you mention probably don't have as many dev tools. Interesting. :thumbsup:
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I stumbled upon this book in my APress account today and it is so nicely written that in 10 minutes I wrote my first Assembly language program and ran it. Beginning x64 Assembly Programming: From Novice to AVX Professional: Van Hoey, Jo: 9781484250754: Amazon.com: Books[^] Over the years I've looked at Assembly and tried it out a little, but it's never been easier to try than now. I have Debian running in a VirtualBox so I quickly: 1. installed nasm (Netwide assembler). 2. Installed GCC tools 3. installed make 4. created a makefile as led by the book 5. typed in the sample program 6. let the makefile build and link the program. 7. ran it. That's very cool. This author is obviously really good because he gets right to the point and explains things clearly. I am impressed and I always like to read a good book that is so well-written.
ld hl, 3c00hl1: ld a, (hl)
xor a, 0BFh
ld (hl), a
inx hx
ld a, h
cmp 40h
jne l1
retMy first assembler subroutine, in Z-80assembler, for the TRS-80. First written circa 1979 and reprinted from memory. Now the tricky part: 21 00 3C 76 EE BF 77 23 7C FE 40 20 F5 C9 That's my best guess to the machine codes for that. (It steps through the monochrome graphics screen, inverting the bit, changing black->white, white->black on the image.) UPDATE: I just googled it. The correct machine code would be:
21 00 3C
7E ; funny thing. I wrote 7E on the scrap paper I figured it out on, then wrote 76 here.
EE BF
77
23
7C
FE 40
20 F3 ; relative jump starts counting from the address of NEXT op code.
C9Truth, James
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I stumbled upon this book in my APress account today and it is so nicely written that in 10 minutes I wrote my first Assembly language program and ran it. Beginning x64 Assembly Programming: From Novice to AVX Professional: Van Hoey, Jo: 9781484250754: Amazon.com: Books[^] Over the years I've looked at Assembly and tried it out a little, but it's never been easier to try than now. I have Debian running in a VirtualBox so I quickly: 1. installed nasm (Netwide assembler). 2. Installed GCC tools 3. installed make 4. created a makefile as led by the book 5. typed in the sample program 6. let the makefile build and link the program. 7. ran it. That's very cool. This author is obviously really good because he gets right to the point and explains things clearly. I am impressed and I always like to read a good book that is so well-written.
Takes me back. In the '80s, if you wanted something fast, you did it in assembly language. MASM in those days. I wrote *a lot* of it. I knew this one company who wrote an entire accounting system in it, which was pretty impressive - very fast and utterly obsolete as soon as Windows 3.1 died. I love assembly language: there's a purity to it which you don't find anywhere else.
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I stumbled upon this book in my APress account today and it is so nicely written that in 10 minutes I wrote my first Assembly language program and ran it. Beginning x64 Assembly Programming: From Novice to AVX Professional: Van Hoey, Jo: 9781484250754: Amazon.com: Books[^] Over the years I've looked at Assembly and tried it out a little, but it's never been easier to try than now. I have Debian running in a VirtualBox so I quickly: 1. installed nasm (Netwide assembler). 2. Installed GCC tools 3. installed make 4. created a makefile as led by the book 5. typed in the sample program 6. let the makefile build and link the program. 7. ran it. That's very cool. This author is obviously really good because he gets right to the point and explains things clearly. I am impressed and I always like to read a good book that is so well-written.
I have done a small(ish) ammount of 80X86 assembly when I was at Uni to get a graphics system working always wanted to go down the rabbit hole could never find the time or the book, I have ordered it just need some time now. When you are unemployed and have the time I never have the money for these things. Need to save more (or buy stuff to keep occupied while you can!!)
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ld hl, 3c00hl1: ld a, (hl)
xor a, 0BFh
ld (hl), a
inx hx
ld a, h
cmp 40h
jne l1
retMy first assembler subroutine, in Z-80assembler, for the TRS-80. First written circa 1979 and reprinted from memory. Now the tricky part: 21 00 3C 76 EE BF 77 23 7C FE 40 20 F5 C9 That's my best guess to the machine codes for that. (It steps through the monochrome graphics screen, inverting the bit, changing black->white, white->black on the image.) UPDATE: I just googled it. The correct machine code would be:
21 00 3C
7E ; funny thing. I wrote 7E on the scrap paper I figured it out on, then wrote 76 here.
EE BF
77
23
7C
FE 40
20 F3 ; relative jump starts counting from the address of NEXT op code.
C9Truth, James
-
Takes me back. In the '80s, if you wanted something fast, you did it in assembly language. MASM in those days. I wrote *a lot* of it. I knew this one company who wrote an entire accounting system in it, which was pretty impressive - very fast and utterly obsolete as soon as Windows 3.1 died. I love assembly language: there's a purity to it which you don't find anywhere else.
-
I stumbled upon this book in my APress account today and it is so nicely written that in 10 minutes I wrote my first Assembly language program and ran it. Beginning x64 Assembly Programming: From Novice to AVX Professional: Van Hoey, Jo: 9781484250754: Amazon.com: Books[^] Over the years I've looked at Assembly and tried it out a little, but it's never been easier to try than now. I have Debian running in a VirtualBox so I quickly: 1. installed nasm (Netwide assembler). 2. Installed GCC tools 3. installed make 4. created a makefile as led by the book 5. typed in the sample program 6. let the makefile build and link the program. 7. ran it. That's very cool. This author is obviously really good because he gets right to the point and explains things clearly. I am impressed and I always like to read a good book that is so well-written.
I used to write graphics routines in the late 90s while at uni using TASM (Turbo Assembler). Good old INT13 on Intel x86. Inline ASM in Turbo Pascal was also handy. I implemented a Bresenham line algorithm from C and extracted ROM fonts for pretty graphics. I wrote a system that used INT1C to perform crude TDM multitasking in DOS. Not sure where i found that gem. I still have Peter Norton's book somewhere too. That low level disk access!
