• Please review our updated Terms and Rules here
  • Exhibitor application for VCF West 2022 is now open! If you are interested in exhibiting, please fill out the form here.
  • Here are the results of the VCF East 2022 Post Event Survey: Survey Results

Commodore PC40-III

PhilA

Member
Joined
Feb 19, 2009
Messages
16
Location
Cut Off, Louisiana, USA
Ctrl-Alt S for Standard speed, Ctrl-Alt T for Turbo speed (If supported with a tri-speed processor, depends if you've changed it out) and Ctrl-Alt-D for Double speed.

HTH

--Phil

PS for some odd reason hitting Ctrl-Alt-D repeatedly during the POST bleep-bleep-bleep-bleep-bleep and floppy seek would sometimes make the internal timer go loopy and get the thing to run about twice as fast as usual. Didn't seem to have a detrimental effect on system stability either.
 

uridium

Member
Joined
Jan 18, 2012
Messages
18
Location
Lane Cove, NSW Australia
Hi Amigaz, I have the three diskettes that came with it. I just bought one on fleabay. They are "Installation", "Operating System" (MessyDOS 4.01) and "Utilities" (various crimes like the mouse driver and video set mode and processor speed utils (other than the CMOS and keyboard shortcuts). If your still keen I can pass them on. I'm new here so not sure if there's some kind of upload area, or if I should be doing it externally on my homepage.

Also, have you managed to get it to boot to MessyDOS from floppy? I've not managed to find a drive that the thing will work with. I've tried about 25 drives now including gutting my A500 to see if that was the difference. Seriously at my wits end. Have tried all jumper configs on the floppy-cable board and any combination on drives that have jumpers (pulled down an insane number of config data sheets for various models) ..and have yet to make it boot. The closest I've got is with a 1.44mb Chinon F-357 which makes all the right noises, doesn't give a bios "Floppy 0 configuration error" .. (got excited when this didn't come up I can tell you!) and did the seek, test, motor spun up and it made a clonk sound and said Boot error.

I shook my fist at it right there. So! If you've got it to boot, can I trouble you for the drive model number and your config? Anyway, give me a bell if your still hunting for the disk images and I'll put them somewhere.

Best Wishes,
Al.
 

BuggZ

Experienced Member
Joined
Oct 29, 2008
Messages
283
Location
East Texas
Hi uridium,

Have you ever gotten your PC40-III to boot from a floppy? I recently got a PC30-III (PC40-III motherboard) and can't get any floppy to boot. I have gotten the BIOS to recognize the drives correctly but the Commodore refuses to boot from any floppy disk. I have even gone so far as to swap the working drives (verified to boot from a DOS 6 boot disk) from one of my 486 machines and the Commodore still won't boot. I just get a Boot Disk error. I even tried swapping the ISA floppy controller from the 486.
 

Elvi

Experienced Member
Joined
Nov 23, 2011
Messages
275
Location
Munsala, Finland
Just gonna add a litle from my own experience with a commodore pc-40, not the 40 III but anyway, mine has 2 floppy drives, a 5.25" 1.2mb, havn't really tested this one and a 3.5" 720kb with an adapter, the 3.5" works just fine in 720kb mode but not 1.44mb, maybe that's where it is wrong for you guys?
My PC-40 has a 286 cpu, don't really know what the 30-III and 40-III has though.
 

BuggZ

Experienced Member
Joined
Oct 29, 2008
Messages
283
Location
East Texas
The PC30-III has a PC40-III motherboard and is a 286 running at 12MHz. I have a 1.2M 5 1/4" (Drive 0) floppy installed and a 1.44M 3 1/2" floppy (Drive 1). The drives were confirmed working in a 486 based system and are recognized when installed in the Commodore PC30. The 486 will boot from the 5 1/4" drive with a DOS 3.1 and a DOS 6 boot disk. Transferring them into the PC30 and I get a "Disk Boot error" using the same boot disks. I have tried installing the 5 1/4 only in the PC30 but still get the same boot error. I tried the 3 1/2 only with a good boot disk - same result. I've changed the floppy cable and even installed the ISA floppy controller from the 486 system - no joy. I've even tried a 360K 5 1/4 and a 720K 3 1/2 drive in the system. I don't have a hard drive that meets the BIOS drive table settings on the PC30 or I would set up a bootable hard drive in another system and transfer it to the PC30 just to verify the system will boot to DOS. This one has me baffled.
 

Druid6900

Veteran Member
Joined
May 7, 2006
Messages
3,809
Location
Hamilton, Ontario, Canada
IIRC, one of the switch setting disables the floppy drives (for school use, most likely).

I don't have the settings right at hand, but, I know I found them somewhere when I was working on the two units I have and ISTR that was one of the settings.
 

BuggZ

Experienced Member
Joined
Oct 29, 2008
Messages
283
Location
East Texas
From what i could find the the two jumpers next to the floppy connector are for disabling the IDE connector and changing the default IDE configuration. I've tried the jumpers in every possible combination and they made no difference. I finally was able to configure a SCSI hard drive and CD-ROM in another machine and transplant them into my PC30. The SCSI card has a floppy connection which I enabled but the system will still not read or write to the floppy drive. I even tried setting the DRIVPARM in CONFIG.SYS but it still doesn't like the floppy drive. Since I have a CD-ROM installed and also an external ZIP drive available and working, I'll worry about the floppy problem after I complete some of the other systems awaiting repairs / upgrades.
 

emilen72

Member
Joined
Mar 26, 2013
Messages
15
Location
Terni, Italy
sorry for update a so old tread but I'm looking for the three disk for my Commodore PC30-III... the uridium link's are dead... can anyone re-upload the file?

many thanks from Italy
 

lowlevel

Member
Joined
May 15, 2020
Messages
22
Commodore PC-40 III

Commodore PC-40 III

The PC30-III has a PC40-III motherboard and is a 286 running at 12MHz. I have a 1.2M 5 1/4" (Drive 0) floppy installed and a 1.44M 3 1/2" floppy (Drive 1). The drives were confirmed working in a 486 based system and are recognized when installed in the Commodore PC30. The 486 will boot from the 5 1/4" drive with a DOS 3.1 and a DOS 6 boot disk. Transferring them into the PC30 and I get a "Disk Boot error" using the same boot disks. I have tried installing the 5 1/4 only in the PC30 but still get the same boot error. I tried the 3 1/2 only with a good boot disk - same result. I've changed the floppy cable and even installed the ISA floppy controller from the 486 system - no joy. I've even tried a 360K 5 1/4 and a 720K 3 1/2 drive in the system. I don't have a hard drive that meets the BIOS drive table settings on the PC30 or I would set up a bootable hard drive in another system and transfer it to the PC30 just to verify the system will boot to DOS. This one has me baffled.

Sorry to bring an old dead/thread back, but I was having a problem adding a floppy drive to a Commodore PC-40 III as well. I landed here in my fruitless search looking for answers and felt this was a good place to comment in case anyone else ends up in this boat.

Adding the 3.5 as a second drive worked fine as long as the cable remained straight and the Commdore 5.25 is primary drive. Trying to use a flip style cable results in drive not ready/floppy configuration errors and the like.

Back when this thing came out, most drives had 4 jumper positions to set DS0 through 3 and used straight through cabling. Using modern drives is a bit of a problem here in that they're set to DS1 and expect you to use a flipped cable to determine A: or B: The PC40-III I encountered, expects A: to be on DS2, and B: to be DS1 so flipping 0 and 1 as most systems expect, won't work here. Further, there is only one motor line on pin 16.... which should not 'flip' or move.

I ended up modifying a flippy cable to allow both drives to be set to DS1. Instead of flipping 7 wires/pins 10 through 16, only flip 3 wires 10 11 12. Then change the 5.25" to DS1 instead of DS2 and you can have either in A: or B: working properly.

I believe sometime after serial number 4500ish, Commodore revised the board to use the IBM AT/flipped cable, as the service manual suggests a revision 5 board has this scheme implemented on the floppy interface.

Only time I ever needed a logic probe to install a floppy drive!
All the best.

Stuart
 
Top