8085 Assembler?

[firewalker]

I have an 8085 training kit. Is there any free assembler for 8085?

[T3sl4co1l]

Shrug, I've got a copy of TASM 3.1 that supports several instruction sets, 8085 and Z80 among others (I was using it for Z80 when I was).  Seems a cromulent assembler, nothing special, no macros I think.

Tim

[tggzzz]

If you are keying it in on a hex keypad, you might as well convert the assembler to hex manually!

[firewalker]

Yes I could!

Alexander.

[T3sl4co1l]

A friend does exactly that, on his vintage dev board.

Tim

[firewalker]

The only one I found that seems promising is The Macro Assembler AS.

http://john.ccac.rwth-aachen.de:8000/as/

Alexander.

[jesuscf]

Baaaack in the day, I used asm80 and plm80 to write programs for the 8085 microprocessor in an Intel MDS running the ISIS II "operating system" (with 8" floppy disks!).  Those compilers worked at some time under DOS.  Apparently the tools are recreated/recompiled here for modern operating systems (I hadn't tested them):

https://github.com/ogdenpm/intel80tools

Bitsavers has documentation for all those tools:

http://www.bitsavers.org/pdf/intel/ISIS_II/

If you search deep enough, you may be able to find the original asm80 for ISIS together with an ISIS emulator that would probably run on DOSbox.

[GeorgeOfTheJungle]

https://www.asm80.com/
http://duckduckgo.com/?q=8085+online+assembler

For the 6502, there's one online that can even upload to the Apple II via the cassette port :-)

[rstofer]

There are CP/M 2.2 emulators around and they may include MAC, the Digital Research Macro Assembler.  They will almost certainly include ASM80, the standard assembler.

[SiliconWizard]

Speaking of CP/M, some may like this:

http://www.cpm.z80.de/source.html

[westfw]

Is there any free assembler for 8085?

Don't forget that the 8085 is essentially just an 8080 internally, with only two extra instructions (RIM, SIM)8080 assemblers are pretty common.

[legacy]

I haven't tried it. I cannot offer any feedback.
If you dare experimental stuff, you can try this 

[firewalker]

Is there any free assembler for 8085?

Don't forget that the 8085 is essentially just an 8080 internally, with only two extra instructions (RIM, SIM)8080 assemblers are pretty common.

If my understanding is correct, Z80 is binary compatible with 8080 and 8085. So any Z80 assembler can be used. Correct?

Alexander.

[oPossum]

Is there any free assembler for 8085?

Don't forget that the 8085 is essentially just an 8080 internally, with only two extra instructions (RIM, SIM)8080 assemblers are pretty common.

If my understanding is correct, Z80 is binary compatible with 8080 and 8085. So any Z80 assembler can be used. Correct?

Same core binary instruction set, but some different mnemonics. LD instead of MOV for example.

[T3sl4co1l]

Z80 has tons more registers, it is not backwards compatible.  80 is forwards compatible (and x86 is designed to be easy to migrate to, but is in no way binary compatible).  If you carefully restrict yourself to use the compatible subset, you could use a Z80 assembler.

Tim

[obiwanjacobi]

Over at the programming topic:
https://www.eevblog.com/forum/programming/simple-python-based-8085-assembler/

[2c]

[David Hess]

If you are keying it in on a hex keypad, you might as well convert the assembler to hex manually!

That was the first programming I did you insensitive clod!

We had pads of lined paper forms specifically for doing the assembly manually.  Then I typed the hex values directly into a Prolog PROM programmer.

After a while, you know all of the important opcodes.

[GeorgeOfTheJungle]

After a while, you know all of the important opcodes.

But calculating the relative back/forward offsets isn't fun...

[SiliconWizard]

After a while, you know all of the important opcodes.

But calculating the relative back/forward offsets isn't fun...

It's a pain.
I also did this back when I had a Z80 single board to play with. Of course didn't have any other computer that could host a (cross-)assembler back then.

When I got my first CP/M machine, it came with no assembler actually AFAIR (or maybe I just didn't know it did, I had very little documentation)... I wrote my own in Pascal (Turbo), and added a feature to automatically generate machine code that could be directly inlined in Pascal code. That was fun.

[David Hess]

After a while, you know all of the important opcodes.

But calculating the relative back/forward offsets isn't fun...

8085 only uses absolute addresses.

If you are not sure about instruction length, then use the longer form and insert NOPs as required later.  Does anybody remember phase errors in assemblers?

Notice that NOP is 00000000b so it can be later overwritten in an additional programming pass.  This makes it possible to patch code which has already been burned to memory.

[tggzzz]

If you are keying it in on a hex keypad, you might as well convert the assembler to hex manually!

That was the first programming I did you insensitive clod!

We had pads of lined paper forms specifically for doing the assembly manually.  Then I typed the hex values directly into a Prolog PROM programmer.

After a while, you know all of the important opcodes.

Actually too acutely sensitive.

The first computer I designed and made had binary switches. The first I bought had a hex keypad (an Acorn system 1), and I showed a proof of concept in 10% of the expected time I then saw people using an 8086 with a hex keypad, which was far too heroic for me!

Apart from that, the first computer I used had a 39-bit word.

[GeorgeOfTheJungle]

After a while, you know all of the important opcodes.

But calculating the relative back/forward offsets isn't fun...

8085 only uses absolute addresses.

I'm not sure if that makes it even worse yet... ?

If you are not sure about instruction length, then use the longer form and insert NOPs as required later.  Does anybody remember phase errors in assemblers?

I don't, what's that?

[David Hess]

If you are not sure about instruction length, then use the longer form and insert NOPs as required later.  Does anybody remember phase errors in assemblers?

I don't, what's that?

A phase error occurs when addresses do not match between passes.  This could occur if the instruction length changes between passes.  It is more common with ISAs which support short jumps:

https://dfdeboer.github.io/S05/304/PH_ERROR.HTM

[GeorgeOfTheJungle]

A phase error occurs when addresses do not match between passes.  This could occur if the instruction length changes between passes.  It is more common with ISAs which support short jumps:

https://dfdeboer.github.io/S05/304/PH_ERROR.HTM

 Hahaha, primitive tools!

My favourite ISA back then only had 16 bit jump (absolute or indirect), and 8 bit relative conditional branch.

[jesuscf]

If you are keying it in on a hex keypad, you might as well convert the assembler to hex manually!

That was the first programming I did you insensitive clod!

We had pads of lined paper forms specifically for doing the assembly manually.  Then I typed the hex values directly into a Prolog PROM programmer.

After a while, you know all of the important opcodes.

So did I for the Micro-Professor MPF-I board with a Z80 microprocessor!  (https://en.wikipedia.org/wiki/Micro-Professor_MPF-I)  After a while you get really good at it.  In this video



Bill Gates talks about Paul Allen doing exactly the same: writing a simple boot loader for the Altair 8800  (in assembly for the 8080 microprocessor) in a flight to Albuquerque New Mexico and later keying it by hand bit by bit.  Funny how Bill Gates brags about writing a better boot loader than Paul Allen later on.  The boot loader read the paper tape with the first basic interpreter for the Altair 8800 from Microsoft.