Running L/M in the high memory area (48-64KB)
Running L/M in the high memory area (48-64KB)
Hello.
A seemingly simple question...
There is a way to run L/M in the upper part of memory (C000/FFFF)?
Thanks, Mic.
A seemingly simple question...
There is a way to run L/M in the upper part of memory (C000/FFFF)?
Thanks, Mic.
Re: Running L/M in the high memory area (48-64KB)
What is L/M ???
Re: Running L/M in the high memory area (48-64KB)
Ooops...
I mean M/C, machine code. My mistake, sorry...
I mean M/C, machine code. My mistake, sorry...
Re: Running L/M in the high memory area (48-64KB)
Not sure about 48-64, but I used to run HOT-Z in the 32-48K, it required installing the "M1 NOT" mod. A Google search shows several references.
Regards;
Greg
Regards;
Greg
Re: Running L/M in the high memory area (48-64KB)
Not with an unmodified zeddy, but anything is possible, one needs to stop the ULA from interpreting the M1 instruction fetch as a video cycle, so I'm thinking something like FAST mode only with some sort of hardware toggle to stop the ULA seeing M1 or À15.
Just a quick thought any way.
Just a quick thought any way.
what's that Smell.... smells like fresh flux and solder fumes...
Re: Running L/M in the high memory area (48-64KB)
Well - the new ZXmore is capable to do this by default when using standard video display (even in SLOW mode).
Re: Running L/M in the high memory area (48-64KB)
Hello Greg.I used to run HOT-Z in the 32-48K, it required installing the "M1 NOT" mod...
I know the "M1 NOT" mod, allows the BASIC and the machine code to run up to 32k.
I would like to know if there a similar mod for the area between 32 and 64K to run machine code.
Re: Running L/M in the high memory area (48-64KB)
32K to 48K is within the 32K to 64K region. Normally MC can't be run anywhere above 32768, but the M1 MOD fixed that. That's why HOT-Z was also known as HI-Z, it left all of the standard 16K region for your program. I just don't recall running any MC in the very upper 16K on a real ZX81. Which I guess doesn't answer your question.
Regards;
Greg
Regards;
Greg
- 1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Running L/M in the high memory area (48-64KB)
It is possible to modify a ZX81 so that M/C can be run in the 48k to 64k area, but if this is done, there will be no screen display (as in standard ZX81 display)... So not a lot of use.
You can however store data in this area, including M/C that is relocated to lower RAM where it can be run.
Mark
You can however store data in this area, including M/C that is relocated to lower RAM where it can be run.
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
Re: Running L/M in the high memory area (48-64KB)
Thanks for your answers...
My idea is simply to load M/C at any point between the addresses C000 and FFFF, then run it directly with a command like: "RAND USR address" or "PRINT USR address", without first having to move everything in the low memory. For example: load the part in M/C of a turboloader in high memory and run it when I need it. The purpose is to avoid the use of memory below the address C000...
Thanks again.
Mic.
My idea is simply to load M/C at any point between the addresses C000 and FFFF, then run it directly with a command like: "RAND USR address" or "PRINT USR address", without first having to move everything in the low memory. For example: load the part in M/C of a turboloader in high memory and run it when I need it. The purpose is to avoid the use of memory below the address C000...
Mark, what do you mean? can you be more specific?It is possible to modify a ZX81 so that M/C can be run in the 48k to 64k area, but if this is done, there will be no screen display (as in standard ZX81 display)...
Thanks again.
Mic.