On Sun, Nov 3, 2024 at 10:35 PM Tony Duell via cctalk
wrote:
> This is one of the few high level languages I've seen with a
> specific instruction for self-modifying code.
Don't forget the ALTER statement in COBOL which changes a GO TO
statement in some paragraph somewhere to point to a different
On Mon, Nov 4, 2024 at 12:05 AM dwight via cctalk wrote:
>
> I/O addresses for the 8080 come to mind.
BASIC-09 under OS-9 (6809 processor) lets you execute a system call
from a BASIC program. The problem is that a system call is coded as a
software interrupt instruction followed by a byte giving
On 11/3/24 15:56, dwight wrote:
> I/O addresses for the 8080 come to mind.
> Dwight
Well, in theory you could avoid that one by constructing 256-entry
tables for IN and OUT instructions and using a computed CALL/JUMP to
access the right one. The 8080 I/O address space is only 256 addresses.
Not
I/O addresses for the 8080 come to mind.
Dwight
From: Chuck Guzis via cctalk
Sent: Sunday, November 3, 2024 3:36 PM
To: Mike Katz via cctalk
Cc: Chuck Guzis
Subject: [cctalk] Re: Self modifying code was HCF
On 11/3/24 14:48, Mike Katz via cctalk wrote
On 11/3/24 14:48, Mike Katz via cctalk wrote:
> Though not Halt and Catch Fire you guys are forgetting the joy of self
> modifying code.
Indeed, this was the *only* way to do things on early first- and
second-generation systems. Even the lowly 1620 CADET, without the
optional indirect addressing
Though not Halt and Catch Fire you guys are forgetting the joy of self
modifying code.
That is how many PDP-8 programs worked. Even the bin loader where the
jump to loop instruction would be replaced with a jump to loaded program
start by the loader itself.
There were many programs that wer
