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TRS-80 Model 4 CP/M Plus

dittman

Veteran Member
Joined
Jul 31, 2017
Messages
662
Location
Plano, TX
Is there anyone that would like to test my Model 4 CP/M Plus and give me feedback? I'm to the point where I want to make sure it works on systems other than my 4D. You'll need to have familiarity with CP/M and the ability to write DMK images to real disks.

One particular system I need it tested on is a 4P. The disk format I used 30+ years ago was five 1K sectors per track. Later when I got a 4P I found out the 4P ROM had a bug where floppies with 1K sectors were assumed to be for Model III mode and therefore required loading MODELA/III. I patched the ROM but now don't have a 4P with the original. I've changed to a disk format with ten 512-byte sectors and want to see if an unmodified 4P will boot it without requiring MODELA/III or hitting key combinations to bypass. If I remember correctly (it's been 20 years since I first got the 4P) the key combination to bypass loading the Model III ROM image did not work. It may have just been that the key combinations worked but it was just a pain to do it every time I booted.

These are DMK floppy images. Due to a bug in the xtrs and TRS32 floppy emulations it won't work on the current released versions of either (or sdltrs which uses the xtrs source). Both Tim Mann and Matthew Reed have fixed the bug in their emulators. Matthew Reed is still working on some other updates and hasn't released the updated version of TRS32 yet but Tim Mann has an updated version of xtrs on GitHub. I haven't been able to build a fixed copy of sdltrs on my Mac since the versions of Xcode I have won't compile it.

Send a PM if you would like to test. The source will be released at a later point.
 

lafos

Experienced Member
Joined
Jun 24, 2015
Messages
427
Location
Sioux Falls SD
I tried to write the disks with David Keil's emulator. Turns out, neither Alphasite's nor Tandy's CP/M Plus will work with real floppies on my system. I can write Montezuma Micro CP/M, MultiDOS (SD Model I), and even copy-protected disks using TRAKCESS. I have both 3.5" 720K and 5.25" 360K drives.

Has anyone written real floppies in CP/M Plus using Keil's emulator?
 

TomL_12953

Experienced Member
Joined
Jul 30, 2003
Messages
63
Location
Malone, NY
Re: TRS-80 Model 4 CP/M Plus

I tried to write the disks with David Keil's emulator. Turns out, neither Alphasite's nor Tandy's CP/M Plus will work with real floppies on my system. I can write Montezuma Micro CP/M, MultiDOS (SD Model I), and even copy-protected disks using TRAKCESS. I have both 3.5" 720K and 5.25" 360K drives.

Has anyone written real floppies in CP/M Plus using Keil's emulator?

I know this is an old thread but I just got this working in Keil's emulator! It turns out you have to use the floppy driver starting with V rather than the ones that start with F.
Example: I was using FDD1_360.DSK (40 track disks in a 360K PC B: drive) as my physical floppy drive. What I need to use is VDD1_360.DSK. The V driver can be used for variable sector disks which is what CP/M Plus disks are. The downside to using the V driver is that it's a bit slower than the F driver. I don't notice a difference, though, so I'll use it all the time from now on so I don't have to keep switching back and forth when writing standard disks and CP/M disks.
 
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