PC 8201A Machine Code Execution

[blahb...@gmail.com]

Hello,

I recently acquired a 1983 PC 8201A computer, and I would like to know
how to run assembly programs on it. The instruction manual lightly
touches upon this topic, but the information is incomplete, and I
can't figure out how to actually save and execute the Intel 8085
assembly code. Step-by-step instructions would be appreciated.

Also, the instruction manual states that I should end my code with
"RET", but various 8085 code examples on the internet end with "HLT".
Should I terminate my code with both of these, or just with "RET"?

Thanks,
Michael Reiley

[A Nother]

<blahb...@gmail.com> wrote in message
news:651d8e62-3d30-49b0...@1g2000prg.googlegroups.com...

> Hello,
>
> I recently acquired a 1983 PC 8201A computer, and I would like to know
> how to run assembly programs on it. The instruction manual lightly
> touches upon this topic, but the information is incomplete, and I
> can't figure out how to actually save and execute the Intel 8085
> assembly code. Step-by-step instructions would be appreciated.

You need an assembler and debugger for this model. It can and has been
written in basic but it's not easy. http://club100.org/ is a good starting
place. There might be some dribs on CompuServe (Vintage Computing).

> Also, the instruction manual states that I should end my code with
> "RET", but various 8085 code examples on the internet end with "HLT".
> Should I terminate my code with both of these, or just with "RET"?

For now stick to RET.

[Frank Durda IV]

blahb...@gmail.com wrote:
: Hello,

Is there somewhere to RETurn to? If not, HaLTing may be appropriate.

If a return address exists on the stack, such as that of a program
exit routine or command interpreter (frequently left there by the
ROM monitor or operating system just before handing control over
to your program), doing a RET would be a reasonable way to end the
program and have the computer then be able to do other things.
HLT tends to be the end of the world, until the CPU is reset
or the CPU receives an interrupt.

The 8085 instruction set only has two instructions extra from what the
8080 had, so documentation on the 8080 assembly language would
be useful. You will also need to know something about the ROM monitor
or operating system environment on that computer to know what it
does for you and how it expects to be able to hand control to
your program and then get back control when your program ends,
assuming of course that it wants control back once your program ends.

A simple 8080 assembler written for Model 4 BASIC (and probably
would run on other versions of BASIC from that period) along with
some related 8080 assembly language information (including a list of
all 8080 instructions) is available at:
http://nemesis.lonestar.org/computers/tandy/software/apps/m4/qd/

I have no specific information on the 8201A system you mention.
Hopefully you can locate the documentation and any operating
system software that went with this system.

Frank Durda IV - send mail to this address and remove the "LOSE":
<uhclemLOSE.jun08%nemesis.lonestar.org> http://nemesis.lonestar.org
"The Knights who say "LETNi" demand... A SEGMENT REGISTER!!!"
"A what?" "LETNi! LETNi! LETNi!" - 1983
Copyright 2008, ask before reprinting.

[Michael Black]

On Tue, 29 Apr 2008, Frank Durda IV wrote:

> I have no specific information on the 8201A system you mention.
> Hopefully you can locate the documentation and any operating
> system software that went with this system.
>

Isn't it one of the other laptops that used the same basic design
as the Radio Shack Model 100? That number sounds right.

Michael