Recent posts

#11

Applications (CPC and CPC-related) / Re: HDCPM - boot and run CP/M ...

Last post by d_kef - Today at 17:08

Interesting! I don't know, but has been CP/M prepared in the past for such kind of things (mounting activities) or did you change something?

CP/M Plus natively supports devices up to 16 MB. In addition it's the only native CPC OS which allows to use the full power of the Z80 - means use 2nd register set. This can speed up applications up to 30%-40% compared to a Z80 which does waste the 2nd register set for f.e. interrupt handling like the native OS (you see, they worked on 8080 before). Since CP/M 2.2 is using the Firmware as BIOS it also doesn't allow to use the genius 2nd register set sadly.

I was thinking more about "mounting" a device during runtime. I understand that a floppy or drive will be recognized and mounted by CP/M during the boot process, but it seems that is also possible after that process; some kind of "hot-plug-in". Tables / internal device lists have to be adapted... ? (It's obviously that I don't understand the CP/M system architecture )

You can change a disk as long as the DPB of the new one is the same to the old one.
In that case the partition or image is treated exactly like a floppy disc.
CP/M Plus can tell if the disk is fixed or removable by examining the CKS property of the DPB and re-initializes the directory allocation table etc. after the disk change.
The trick with the MOUNT.COM is that you can mount a new image (or partition) only if the mount point has been initialized/used during boot time. So if you mount CPMDSK01.IMG and CPMDSK03.IMG during boot, then you can only use mount points 1 and 3 with MOUNT.COM

d_kef

#12

M

Other retro / Re: C64 Nightmares Kickstarter

Last post by merman - Today at 17:00

48 hours to go and we've hit £20,000

#13

Applications (CPC and CPC-related) / Re: HDCPM - boot and run CP/M ...

Last post by d_kef - Today at 15:56

@d_kef I have just swapped out the 1.10 ROM with the 1.11 ROM on my 464 (same config as before) but it just causes the machine to reset over and over again on power up before loading the new ROM. Any ideas?

EDIT: To clarify, I used CP/M Image File Explorer (image type cpcdata) to open Hdcpm111.dsk, then copied the hdcpm.rom file to my hard drive, and replaced the existing HDCPM ROM in the M4 slot with the new one. Maybe the file didn't copy correctly (although I did try again)? Is there a checksum I can compare it against?

Maybe it would be a good idea to put the ROM file itself on the download page, as I think this would be easier for many people.

Just tested the ROM and BIN with my 464, M4 and revaldinho's Universal 512K RAM.
It works without any restarts or any other strange behaviour.
The ROM itself does a checksum test during boot (since v1.10), so it will display an error message in case of data corruption.

Anyway I'm attaching the ROM here just in case.

d_kef

#14

News & Events / Re: Release of Amstrad Cpc Crt...

Last post by lmimmfn - Today at 14:08

A dump of the CPC ROM should be directly executable via calls to same, i.e. can take hex from ROM and directky decompile without issue, unless I'm misunderstanding what you say?

It is not a original Amstrad ROM, but an extension ROM from Vortex and they put it in a hardware box, that does the job.

See here for a complete reverse engineering of the hardware part here, as well as the beginning of the software dissassembly.

https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/analysis-and-reverse-engineering-of-the-x-modul-vortex/

Also more discussion on how to descramble in software in here:
https://www.cpcwiki.eu/forum/programming/disassembly-with-descrambling/

ahh that makes sense, thanks, @McArti0 didnt realise Vortex had its ROM and that its encrypted.

#15

Applications (CPC and CPC-related) / Re: HDCPM - boot and run CP/M ...

Last post by pollito - Today at 12:45

@d_kef I have just swapped out the 1.10 ROM with the 1.11 ROM on my 464 (same config as before) but it just causes the machine to reset over and over again on power up before loading the new ROM. Any ideas?

EDIT: To clarify, I used CP/M Image File Explorer (image type cpcdata) to open Hdcpm111.dsk, then copied the hdcpm.rom file to my hard drive, and replaced the existing HDCPM ROM in the M4 slot with the new one. Maybe the file didn't copy correctly (although I did try again)? Is there a checksum I can compare it against?

Maybe it would be a good idea to put the ROM file itself on the download page, as I think this would be easier for many people.

#16

General Discussion - Introductions / Re: Interview with Martin Pede...

Last post by eto - Today at 11:12

I never heard of "The Vikings" and I can't even find a gameplay video... seems to be a hidden gem. 

#17

S

General Discussion - Introductions / Re: What computer did you have...

Last post by St-BeidE(DE/GB) - Today at 10:19

Maybe only 50 have a keyboard? 

#18

General Discussion - Introductions / Re: Interview with Martin Pede...

Last post by Skunkfish - Today at 08:06

Great interview. I've not played The Vikings, I really should check it out!

#19

General Discussion - Introductions / Re: Interview with Martin Pede...

Last post by Herman - Today at 07:39

I didn't know that Martin "Hybris-on-Amiga" Pedersen had previously worked on our lovely CPC and made games there.

Thanks, Dubliner, for all the background information revealed by this interview. Man lernt nie aus.

#20

General Discussion - Introductions / Re: Why did you choose the CPC...

Last post by McArti0 - Today at 07:20

cheapest model: CPC464 with a GT65*.

800xl and c64 were more expensive???