CP/M Plus or patch with 80 Track (704k) support

[HAL6128]

I have searched for a long while ... Is there a CP/M plus version available which is patched to support 80 Tracks drives (on B:) for reading 704k / 716k discs(e.g. ROMDOS D1)?
I found a tool at "gaby.de" but it doesn't work.

[GeoffB17]

Hello,


Not familiar with 'RomDos', but checking a file on the Gaby site, which seems to be a disk format spec file for 22Disk, which includes a definition for 'RomDos D1 Data 716k, this format seems to be pretty much the same as the standard 80T format for Amstrad except that there are NO reserved tracks.   In other words, the disk goes right into the directory area.   So no place for the little format header that the system would normally read.


This may be the only 'problem' you might have?


If that is the case, then note that this can be turned OFF, i.e. the system can be told NOT to try to read this data.  If this was set - OFF - and other info was set so that the relevant data was read anyway and set into the XDPB, then I would assume you could read such a disk.


I did this years ago, I had a special disk that was a disk for two different CP/M machines, and could be read by both.   The disk had a normal PCW format apart from no format sector in sector 0, there needed to be something else there for the other computer.   So both machines could read the disk, just that the PCW did NOT look for the format data.


Would something like this help?  I'll have to dig out my code for this?


Geoff

[Terje_Norway]

Hi,


I think I have the solution for You 


You have probably searched for the wrong DOS version 


1.) ROMDOS is a ROM version. Can be used with AmsDOS ! ! !
2.) RAMDOS is a RAM Version. Can be used in AmsDOS, CP/M 2.2 and CP/M+ (3.1)


CP/M isn't using any extended hardware without being told so. Drive B and memory expansions being Dk'tronics compatible, is probably one of very few things that works without modifying CP/M.
You should be looking for a program called RAMDOS+.COM This program will solve all Your problems.
I have not tested it TODAY, but that was the program I used back in the old days, before I did modify a copy of CP/M to accept ROMDOS D1 in drive B:


You can find the program, and instructions in the following link :


The Trailing Edge of Technology


Have good luck with it, as it'll probably solve Your problems.


Yours

Terje Grind
NORWAY

PS If Your using CP/M very often, I would also recommend You to have look at a program published in the Danish Amstrad Bladet (probably issue 10-88), that saves the CP/M bootup as an regular AMSDOS file.
That means the file can be started from any disc format. An DATA formatted disc in drive A: or even better on a ROMDOS disc in drive B:
You'll naturally have to modify CP/M to start it from drive B:

[HAL6128]

Thanks to you both Terje_Norway and GeoffB17!!

Both answers are very helpful.

@Terje_Norway: I will try to use RAMDOS+.COM as an approach. I will also try to follow the recommended "Danish Amstrad Bladet". Sounds very promising! Yes, I want to start CP/M often. Does it mean if I start CP/M from the drive B (with ROMDOS D1 formatted) it could read the disc if it reach the CP/M OS without calling RAMDOS+.COM?

@GeoffB17: Yes, your approach is to patch the XDPB table of CP/M plus. I have found out that CP/M plus is able to read 80 Track Discs but not by default. That would also mean a 716/704k disc, but I don't know if a special ROMDOS D1 format. Do you have your code available?

HAL6128

[Terje_Norway]

Hi,


Happy to be of any help for a fellow CPC user and especially CP/M+ user. 
Unfortunately the majority of CPC users doesn't have much knowledge of this excellent OS. There is a huge amount of excellent software for it.
SUPERCALC II, Dbase II and WORDSTAR just to mention a few.


The program mentioned earlier is to be found on the following link :


http://www.cpcwiki.eu/imgs/1/15/Amstrad_Bladet8810030.jpg


In short, this program takes the .EMS file and converts it into a standard .BIN file.


For instance IF You want CP/M+ to be able to use ROMDOS D1 disc as standard drive B: format, You have to patch the CP/M (.EMS file) prior to running the program from Amstrad Bladet.
The ultimate CP/M+ version is the ROM version of it. You can easily find it on the net, and You'll be able to start CP/M from ROM. For that You'll need a ROMBOARD solution.
Check out Bryce's and Toto's boards. Unfortunately that solution makes it a bit more complicated for CP/M to accept ROMDOS drive B: formats at startup, but it's doable.


Yours

Terje Grind
NORWAY

PS In the Dk'tronics Silicon Disc SDISC.ROM there is a command for adding up additional dk'tronics compatible memory to the CP/M+.
A really useful command if You have Toto's X-MEM card or the original dk'tronics memory expansions.
It gives You a 444K RAMDISC.

[steve]

I think if you want to run CP/M, it would be better to use a PCW, but out of interest is there any CP/M software that uses the CPC's colour graphics or sound capabilities?

[GeoffB17]

Re: 'HAL6128'


I attach a .ZIP file.


This contains my 3 little progs, .ASM and .CPM (to be renamed as .COM)


FSWITCH merely turns the read flag on/off


DSWITCH also, but as well sets the drive to SS


NSWITCH again as FSWITCH, but sets back to DS


These were to work with my PCW, using the 5.25 40T floppy drive, 350k format (allowing for reserved track).


These processes assume that a 'normal' disk has already been read, and therefore the other parameters of the XDPB are all already set as required.   If this has NOT been the case, and I suspect that this will apply to what you want, then other data items should also be set.   The format you need will be the same in most regards as the normal 80T b: format, except that the value for reserved tracks goes from 1 to 0 and the total number of blocks will increase also to allow for the extra track.


The bit of code in NSWITCH that sets the 081h will probably need to be simply 1 for standard disk (the 81 is a special ## for the 5.25" disk).


This is all based on info regarding the XDPB in the book 'The Amstrad CP/M +' by Clarke & Powys-Lybbe.


Sounds like you basically need to set a DATA ONLY format, but for the 80T drive, and turn OFF the format read as the format info will not be there.


However, as far as I can tell, my PCW will read a data only format OK, so maybe it does NOT need this doing.   However, this is in drive A:, I've never tried this in B:, and the DATA format might not be accepted there?


If you've not got an assembler, I could do the extra changes you require, but I've got no way to test.   Hmm, if pressed, I could use 22Disk to create a 3.5" disk with what I believe (??) to be the right format, based on the info in that disk defn file from Gaby, and then see how my PCW responds, and tweak my prog to get it to read?


Just comparing the data from Gaby with that in the book, looks like MOST of the numbers would need changing.  The Gaby file shows:


BSH=4, BLM-15, EXM=0, DSM=359, DRM=127, AL0=0C0H, AL1=0, OFS=0 for 716K format


If you need any further info, let me know.


Geoff

[||C|-|E||]

I think if you want to run CP/M, it would be better to use a PCW, but out of interest is there any CP/M software that uses the CPC's colour graphics or sound capabilities?

Our text adventure uses Mode 1 graphics in CP/M 

[TFM]

I have searched for a long while ... Is there a CP/M plus version available which is patched to support 80 Tracks drives (on B:) for reading 704k / 716k discs(e.g. ROMDOS D1)?
I found a tool at "gaby.de" but it doesn't work.

IIRC on my homepage I provide CP/M Plus with Protext, which should support 0.7 MB Vortex format and HD20 support. (IIRC)

[HAL6128]

IIRC on my homepage I provide CP/M Plus with Protext, which should support 0.7 MB Vortex format and HD20 support. (IIRC)

Hi TFM, I only found a disc called "180 ..." with 396 kByte format. Is the the Vortex format different to the ROMDOS D1?

[TFM]

Yes, of course, they are different. Vortex has System tracks, so you can boot CP/M from it. 


See attached file for a CP/M with Vortex format on B and RAM-disc support. If you need anything else, I will find it :-)

[HAL6128]

Thanks for it! I will give it a try. How can I format a disc? (assuming that VDOS is necessary?)

[TFM]

Thanks for it! I will give it a try. How can I format a disc? (assuming that VDOS is necessary?)

Having a VDOS (or better X-DDOS) ROM connected you can use the !FORMAT command. IIRC !FORMAT,1 will format drive B. Or you can use FutureOS if available. Don't remember a CP/M tool, there may be one from Vortex for CP/M 2.2 but I have to check...

[FloppySoftware]

Hi everybody.

Is there any CP/M Plus version for the CPC able to boot from an A: 720 kb disc?

Thanks a lot.

[TFM]

If you adapt the DPB it should be no problem. There is a tool for setting formats of 0.7 MB for drive A too. It depends only WHICH format you want to use.

[FloppySoftware]

If you adapt the DPB it should be no problem. There is a tool for setting formats of 0.7 MB for drive A too. It depends only WHICH format you want to use.

Well, I need one able to boot CP/M Plus with a 720 kb disc.   

Oh, I'm repeating myself? 

What tool please?

Thanks a lot.

[TFM]

Ok, 720 KB disc, but which disc format do you want to use? I may find something for some formats, but not for any one. ... Have to look, is Vortex format ok?
(repeating myself too  ).

[HAL6128]

I think that's what FloppySoftware need. The Vortex has System tracks which is bootable if the 3,5" floppy is the A-Drive.

[TFM]

I think that's what FloppySoftware need. The Vortex has System tracks which is bootable if the 3,5" floppy is the A-Drive.

A small patch (3 bytes) allows to add an Amsdos header to the .EMS file, so it can be started from Amsdos like any other program, this can save the system tracks and enables usage of every format. However only when patching the DPB correctly. (Therefore I ask so much questions here).

How to hack CP/M Plus to run as Binary:
- Usually it loads at &0C00 and starts there
- Now delete (make 3 NOPs) beginning at &0C03 (there's a: CALL &0CD5)
- Save new Binary
- Have fun saving 9 KB on disc (no system format needed, use data format now)

How to load the .EMS file? You could use something like Maxam, Utopia (or FutureOS and it's monitor).

[FloppySoftware]

Hmm... but if I want that CP/M recognize the 720 kb disc in A: on startup, I have to patch the binary before.

What a mess... 

[HAL6128]

How to load the .EMS file? You could use something like Maxam, Utopia (or FutureOS and it's monitor).

How about a patched ROM version of a combination Parados and CP/M which enables a 720 kB disc (romdos or vortex) as Drive A?

[TFM]

Well, I don't want to post some crap here. So first I need a station with a DSDD 80 Track drive as A. Then I can verify what actually works. Maybe I have to use an emulator, but I would prefer the real thing.

[Audronic]

@TFM


If you configure Parados as 704K for drive A.
and REBoot, it will remember the Parameters, and away you go.
No hardware hacks.


Ray

[HAL6128]

Yes, patching ParaDOS is decribed here (http://www.cpcwiki.eu/imgs/3/33/Pdos-ddb.txt).
Patching CP/M (and also AMSDOS) could be done with the tool Terje NORWAY described below.
With the help of TFMs CP/M binary a CP/M should start and recognize a 3,5 inch disc drive from A.

2.) RAMDOS is a RAM Version. Can be used in AmsDOS, CP/M 2.2 and CP/M+ (3.1)
The Trailing Edge of Technology

Terje Grind
NORWAY

PS If Your using CP/M very often, I would also recommend You to have look at a program published in the Danish Amstrad Bladet (probably issue 10-88), that saves the CP/M bootup as an regular AMSDOS file.
That means the file can be started from any disc format. An DATA formatted disc in drive A: or even better on a ROMDOS disc in drive B:
You'll naturally have to modify CP/M to start it from drive B:

[arnoldemu]

Well, I don't want to post some crap here. So first I need a station with a DSDD 80 Track drive as A. Then I can verify what actually works. Maybe I have to use an emulator, but I would prefer the real thing.

My new release of arnold allows you to configure the drive size....