On Saturday, June 18, 2005 at 4:30:03 AM UTC-7, dun...@yahoo.com wrote:
> I noticed a Kaypro 2 for auction on eBay:
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4193&item=5209743159&rd=1&ssPageName=WDVW
> and was wondering how this system differs from the Kaypro II?
> Will CP/M and Boot system disks for the Kaypro II work on the Kaypro 2?
> (and vice versa)
> Paul

in a word, no.
THis is because CP/M boot disks are machine specific in ways that most later OSs aren't...
There are >= 4 models of "Kaypro 2" and >=2 of "Kaypro II".
The "Kaypro II" is a CP/M focused text-mode only machine. z80, dual floppies in low size, full height. I should have one somewhere. I used it a lot in high school. 1 Serial, 1 Parallel.
The "Kaypro 2" is a CP/M focused text mode machine, but with better characters including graphics characters, better floppies, a faster z80.
The "Kaypro 2X (1984)" is an even more plussed up drives and a second serial port.
The "Kaypro II Plus" is essentially an 8088 version of the Kaypro 2X
The "Kayppro 2X (85)" is a kaypro 4X from 1984, rebadged and repriced. I know that this model sometimes was running MS-DOS; I had to help Friar Kent learn MS-DOS on his after he upgraded from an old 2.

Note that some dealers made motherboard and/or drive replacements available back in the day; I think dad had the roms upgraded on the II. (He upgraded to a 286 not long after... I "upgraded" to an Apple //e...)

On Sunday, May 1, 2022 at 1:49:29 AM UTC-5, William Hostman wrote:
> On Saturday, June 18, 2005 at 4:30:03 AM UTC-7, dun...@yahoo.com wrote:
> > I noticed a Kaypro 2 for auction on eBay:
> > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4193&item=5209743159&rd=1&ssPageName=WDVW
> > and was wondering how this system differs from the Kaypro II?
> > Will CP/M and Boot system disks for the Kaypro II work on the Kaypro 2?
> > (and vice versa)
> > Paul
> in a word, no.
> >...
Actually, the booting of CP/M versions on Kaypro's depends on (is tied to) the ROM version. Kaypro II/IV had significantly different hardware than all later models, and so the ROMs that could run there are limited. The Kaypro Technical Manual has a table to show ROM versions and compatible CP/M versions.

However, the basic CP/M file format did not change, aside from single/double sided disks/drives. There should be a fair amount of backwards compatibility maintained (you should be able to read files from a Kaypro II disk on a Kaypro 2X system, for example).

On Sunday, May 1, 2022 at 5:26:52 AM UTC-7, Douglas Miller wrote:
> On Sunday, May 1, 2022 at 1:49:29 AM UTC-5, William Hostman wrote:
> > On Saturday, June 18, 2005 at 4:30:03 AM UTC-7, dun...@yahoo.com wrote:
> > > I noticed a Kaypro 2 for auction on eBay:
> > > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4193&item=5209743159&rd=1&ssPageName=WDVW
> > > and was wondering how this system differs from the Kaypro II?
> > > Will CP/M and Boot system disks for the Kaypro II work on the Kaypro 2?
> > > (and vice versa)
> > > Paul
> > in a word, no.
> > >...
> Actually, the booting of CP/M versions on Kaypro's depends on (is tied to) the ROM version. Kaypro II/IV had significantly different hardware than all later models, and so the ROMs that could run there are limited. The Kaypro Technical Manual has a table to show ROM versions and compatible CP/M versions.
>
> However, the basic CP/M file format did not change, aside from single/double sided disks/drives. There should be a fair amount of backwards compatibility maintained (you should be able to read files from a Kaypro II disk on a Kaypro 2X system, for example).

I used to work at a Kapro dealership while in college doing both programming and repairs on all the models. There was a point in time where there was really no difference between the single sided and double sided floppy machines that shipped from the factory. Okay, there was actually one difference: the jumper settings on each of the drives to select between single sided and double sided. Bought a machine with single sided floppies? Open the case and inspect the drives to see if your free upgrade is simply a matter of moving a jumper on each drive...

Best,
-Mark

On Monday, May 2, 2022 at 10:05:03 AM UTC-5, marksl...@gmail.com wrote:
> ... There was a point in time where there was really no difference between the single sided and double sided floppy machines that shipped from the factory. Okay, there was actually one difference: the jumper settings on each of the drives to select between single sided and double sided. Bought a machine with single sided floppies? Open the case and inspect the drives to see if your free upgrade is simply a matter of moving a jumper on each drive...
>
> Best,
> -Mark

That sounds a bit odd to me. I don't recall ever seeing a double-sided drive with a jumper to disable the second head. It was simply up to the computer whether the second head/side was ever selected.

The first-generation Kaypro II mainboard did not even connect to the drive side-select signal, so no matter what drives, ROM, or CP/M you had you would only get single-sided operation.

Starting with the Kaypro II/4 mainboad, side-select was connected and the ROMs all checked media to see if it was (formattted) double or single-sided. If the machine had single-sided drives, you could never detect double-sided (formatted) media. If the machine had double-sided drives, you got double-sided simply by formatting media as double-sided. No jumpers. No crippled features. Kaypro seems to have quickly abandoned single-sided drives, like the rest of the industry, and except for the gen-1 Kaypro II they could seamlessly just build systems with double-sided drives and the capability was automatically detected. My "2X" is likely an example of that: The case says the model is "2" (presumably 2/84) but the back panel has an "X" sticker next to the "2". This would be consistent with it originally being a 2/84 but finally shipped with double-sided drives.

On Monday, May 2, 2022 at 3:09:46 PM UTC-7, Douglas Miller wrote:
> On Monday, May 2, 2022 at 10:05:03 AM UTC-5, marksl...@gmail.com wrote:
> > ... There was a point in time where there was really no difference between the single sided and double sided floppy machines that shipped from the factory. Okay, there was actually one difference: the jumper settings on each of the drives to select between single sided and double sided. Bought a machine with single sided floppies? Open the case and inspect the drives to see if your free upgrade is simply a matter of moving a jumper on each drive...
> >
> > Best,
> > -Mark
>
> That sounds a bit odd to me. I don't recall ever seeing a double-sided drive with a jumper to disable the second head. It was simply up to the computer whether the second head/side was ever selected.
>
> The first-generation Kaypro II mainboard did not even connect to the drive side-select signal, so no matter what drives, ROM, or CP/M you had you would only get single-sided operation.
>
> Starting with the Kaypro II/4 mainboad, side-select was connected and the ROMs all checked media to see if it was (formattted) double or single-sided. If the machine had single-sided drives, you could never detect double-sided (formatted) media. If the machine had double-sided drives, you got double-sided simply by formatting media as double-sided. No jumpers. No crippled features. Kaypro seems to have quickly abandoned single-sided drives, like the rest of the industry, and except for the gen-1 Kaypro II they could seamlessly just build systems with double-sided drives and the capability was automatically detected. My "2X" is likely an example of that: The case says the model is "2" (presumably 2/84) but the back panel has an "X" sticker next to the "2". This would be consistent with it originally being a 2/84 but finally shipped with double-sided drives.

May sound odd, but there was a period of time where the owner of the dealership had me cracking open the cases, removing the drives, moving the jumpers on the drives, remounting them, and putting the case back on... The dealer I was employed at? Systems Technology Automated Resources. I saved up and later purchased a Kaypro 4 for myself, using it all through college while still working there.

Best,
-Mark

On 3/05/2022 10:02, Mark Lawler wrote:
> ...
> May sound odd, but there was a period of time where the owner of the dealership had me cracking open the cases, removing the drives, moving the jumpers on the drives, remounting them, and putting the case back on...

There were similar stories about memory upgrades for PET computers. Customers
could save money by buying a smaller-memory PET and installing the missing ram
chips themselves as different models began using a common motherboard. There
was even a claim of dealers or factory drilling holes in the motherboard so as
to circumvent that. Strange days indeed.

On Monday, May 2, 2022 at 9:50:08 PM UTC-4, dxforth wrote:
> On 3/05/2022 10:02, Mark Lawler wrote:
> > ...
> > May sound odd, but there was a period of time where the owner of the dealership had me cracking open the cases, removing the drives, moving the jumpers on the drives, remounting them, and putting the case back on...
> There were similar stories about memory upgrades for PET computers. Customers
> could save money by buying a smaller-memory PET and installing the missing ram
> chips themselves as different models began using a common motherboard. There
> was even a claim of dealers or factory drilling holes in the motherboard so as
> to circumvent that. Strange days indeed.

When I was a grad student in Chicago in the '80s, I bought one of the first Kaypro 2 (versus II) models, usually referred to as a 2/84, since that was the model year. Block graphics characters and the ability to underline and bold on screen. One parallel port and (IIRC) two serial ports, two half-height SSDD floppy drives. You could easily swap out the drives for DSDD units (which I did) and it would become, for all intents and purposes, a 4/84.. It came with WordStar but NOT with Perfect Writer (which the II had shipped with). I bought a copy of Perfect Writer since that was my preferred EMACS-like editor, and later built a version of ROFF4 for better text formatting (which I sent to an Okidata Ml92 and/or Anderson-Jacobson teletype). I also had SuperCalc, which was a pretty good spreadsheet for the time, and dBase II, and wrote my own program for generating mailings (which I used to set up interviews for my dissertation).

It would NOT boot off a Kaypro II boot disk, to the best of my recollection, though it could certainly read II,2,IV, and 4 (and 10!) floppies. Sometime after I got it, I added an Advent TurboROM which added many, many features (like a type-ahead buffer) and allowed it to read dozens of different CP/M disk formats, as well as MS-DOS DSDD formatted disks. Still later I added an 8088 co-processor/256K RAMdisk, which made it blazing fast for the time (I preferred Perfect Writer as an editor, and put its swap file on the RAMdisk).

That machine led to my marriage and to about 15 years of employment as a software engineer. Not too shabby!