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General Category => Applications => Topic started by: Nemo59 on 00:18, 10 May 21

Title: CPM 2.2 with B: drive of 720ko and c: virtual disk
Post by: Nemo59 on 00:18, 10 May 21

Hi!


For a new project i need to use banks memory with CP/M on my CPC6128+. I took some time to see if it's possible to patch CPM+ (for example to have the memory block 3 for my own usage)  but it looks very complex and need to create a new CPM+ version. The better (anyway the simpliest ;)  way seems to use CPM2.2 for that, as CPM2.2 juste use the 0..3 blocks of memory.

But is it possible to have, like in CPM+, a CPM2.2 version with a B: drive of 720ko (or Gotek) and a virtual C: drive?

About CPM+, was there some attempts to reduce the memory footage on the CPC ? It looks like the CPM+ on the Amstrad CPC takes all the ram for its own usage with tons of buffers. Reading the Digital Research old documentation, the memory footprint could be much smaller.
Title: Re: CPM 2.2 with B: drive of 720ko and c: virtual disk
Post by: GUNHED on 00:29, 10 May 21
Use Dobbertin CP/M Plus. It has 0,7 MB Vortex format on B: and provides 444KB RAM disc on C:
It's somewhere on my homepage and I uploaded it here too.
Title: Re: CPM 2.2 with B: drive of 720ko and c: virtual disk
Post by: Nemo59 on 00:34, 10 May 21

Thanks, But I already use this for CPM+ ;D It works fine with CPM+ but i need to use CPM2.2 here.
Title: Re: CPM 2.2 with B: drive of 720ko and c: virtual disk
Post by: GUNHED on 00:43, 10 May 21
Use Dobbertin CP/M 2.2 version 1.4. It provides 63 KB TPA, 0,7 MB for B:, 444 KB RAM drive C: and even supports real time clocks (Dobbertin RTC, dxs RTC, LambdaSpeak RTC).
Title: Re: CPM 2.2 with B: drive of 720ko and c: virtual disk
Post by: Nemo59 on 00:53, 10 May 21
Use Dobbertin CP/M 2.2 version 1.4. It provides 63 KB TPA, 0,7 MB for B:, 444 KB RAM drive C: and even supports real time clocks (Dobbertin RTC, dxs RTC, LambdaSpeak RTC).


I ve tried this. The problem with the 63kB TPA in CPM2  is that you loose all the firmware access.

1/ CPM+   : ~ 61 KB of TPA but no access to banks (all used  by CPM) + firwmare acces
2/ CPM2.2 (standard) : only 39kB TPA but easy access to 64KB banks + firmware access
3/ CPM2.2 (extended TPA) : 63kB TPA, banks usage not documented, no firmware access without patch (if possible)...


For now I use the DK'Tronix version of CPM2 wich allow to swap from a standard TPA to an extended TPA. The best for my usage will be something like the CPM2 Dk'Troniks version + B: of 720KB and C: virtual drive (faster for compilation)
Title: Re: CPM 2.2 with B: drive of 720ko and c: virtual disk
Post by: GUNHED on 01:19, 10 May 21
I ve tried this. The problem with the 63kB TPA in CPM2  is that you loose all the firmware access.
No. Look at the TIMEROM source code to see how.
Title: Re: CPM 2.2 with B: drive of 720ko and c: virtual disk
Post by: ComSoft6128 on 08:21, 10 May 21
I have CPM3 for the Plus (Romdos formats on drive B/no drive C) on Rom here and if I remember correctly @VincentGR (https://www.cpcwiki.eu/forum/index.php?action=profile;u=1053) has the images for that, I obviously had them myself at one point but I don't know where they are now.
Title: Re: CPM 2.2 with B: drive of 720ko and c: virtual disk
Post by: Nemo59 on 12:45, 10 May 21

No. Look at the TIMEROM source code to see how.

Thanks. I will see that...  If it's work it will be the best solution ;D

EDIT : Where can I download the source code of TIMEROM ans  the 63 KB Dobbertin CP/M 2.2 (ver 1.4) ?
I found the Dk'Tronics and Vortex CPM 2.2 version but no Dobbertin 2.2 (1.4) version.
Title: Re: CPM 2.2 with B: drive of 720ko and c: virtual disk
Post by: GUNHED on 03:57, 11 May 21

Thanks. I will see that...  If it's work it will be the best solution ;D

EDIT : Where can I download the source code of TIMEROM ans  the 63 KB Dobbertin CP/M 2.2 (ver 1.4) ?
I found the Dk'Tronics and Vortex CPM 2.2 version but no Dobbertin 2.2 (1.4) version.



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