Mike's PCjr Page

Hey friends.
I come and go on this board. I have an awesome PCjr I restored a little over the year ago and have enjoyed it since. Much of not all the help came from this board and I really appreciate it.

I restore a lot of different systems hence the reason i come and go. You have a great resource here that was critical to getting my system running, that I will say is one of the best in my collection.

The reason I'm reaching out is Im pretty sure i read on this board a year or more ago a post or an article that someone wrote about the best way to create a "bridge" computer. What i mean by "Bridge Computer" is I have several CP/M machines Im working on now, a Kaypro II and an Osborne I. I need to create floppy disks for them (SSDD). They are all Shugart drives. I "think" what i need is a 386 machine and drive controllers with 191Kb SS, 360Kb DS, 1.2mb and 1.4mb drives and use 22disk to create and manage those images.

I was hoping someone could point me to that post give me advice regarding what machine and DOS version I should target to get the most out of this and future projects.

Current collection:

IBM PCjr - JrIDE and IBM SSK keyboard (so nice)
Apple IIe Platinum - CFFA3000 drive emu
C64 - (several)
SX64 - (mint)
Mac Color Classic II - SCSI2SD V5
SGI Indy - SCSI2SD V6 - IRIX 6.5
Sun IPC - SCSI 2SD V6 - SunOS 4.1.3
Sun IPX - SCSI 2SD V6 - Solaris 2.6
Kaypro II - HxC Floppy em (not yet installed) - CPM 2.2
Osborne 1: HxC floppy em (needs upgrading) - CPM 2.2

Really, something you can run Windows 98 on may be the most convenient thanks to USB support. To be able to make all those formats, you'll need 3 drives, though, a 360 kb drive, a 1.2 MB drive, and a 1.44MB drive. Due to differences in track width, double-density discs written on a 1.2MB drive will often have issues being read on a double-density drive.

Thanks for the reply. A pentium 1 I think can run W98. I agree I need the 360,1.2, and 1.44. I think that 22disk is rather picky about the drive controller chips. Any suggestions on specific drive controller cards is appreciated. Such a fascinating subject, image how hard it will be to do what im trying to do in another 25 years? !!

I'm normally better about replying to these threads but the CP/M requirement threw me off. I too have some Kaypro in the house and I haven't started working with them yet; all of my knowledge is PC based.

I have a few systems that I use for my machines here:

• 386-40 running DOS: 1.44MB 3.5" and 360KB 5.25" drives; Also a Central Point Option Board
• Pentium 90 running DOS and Windows 98: 1.2MB 5.25" and 1.44MB 3.5" floppy drives
• Pentium 233 running Linux: 1.44MB floppy drive and 100MB ATAPI Zip drive. Also has SCSI.
• Athlon system running Linux: SCSI adapter

Also in the bag of tricks are a 1.44MB floppy drive that is parallel port attached, a CF card reader that attaches to the parallel port, USB to IDE&SATA drive adapters, etc. I can basically handle any PC floppy disk or hard drive except for ESDI. MFM is possible, but I have to pull an XT off the shelf for that.

For software I use my own dskimage program (non-copy protected DOS diskettes), Teledisk (light copy protection or grown errors), and the Central Point Option Board (most copy protected diskettes).

There are newer projects like like the GreaseWeazel (sp?), Kyroflux, MFM drive emulators, etc. that I have not looked at yet.

Thanks Mike.

I've been reading a lot of stuff and as a template i've kind of started watching all the YouTube content on Retro Gaming. I'm not a gamer but those system seem to be pretty interesting as you can buy new Socket 7 boards and they kind of live in that late DOS era I think i need to target. Most have 360K floppy support on the motherboard, although i am bit concerned that 22DISK might not work with them as I don't know how much they look like old controllers from the era. I wish 22DISK worked on my awesome PCjr but i've read the threads about the controller not being compatible due to lack of DMA support. I have read the FreeDOS supports USB sticks without additional drivers but I have never tried that on anything.

-t