• Please review our updated Terms and Rules here

Kaypro 4 and strange behavior with certain CP/M games.

Not all logic boards are compatible with the case. The arrangement of ports on the back changed, so a different logic board might not fit. However, I believe Kaypro did not always ship the exact same hardware under the same label. But, I think it is just as likely that the version of software on the video was different than what you are running. Main board 81-240 is listed as being for the II/4(83). Note, the 4/83 and 4/84 are totally different main boards. Both are commonly referred to as "4". There is a technical document on bitsavers, "Kaypro Technical Manual 1484F", which shows the official part numbers used in various models.
 
Not all logic boards are compatible with the case. The arrangement of ports on the back changed, so a different logic board might not fit. However, I believe Kaypro did not always ship the exact same hardware under the same label. But, I think it is just as likely that the version of software on the video was different than what you are running. Main board 81-240 is listed as being for the II/4(83). Note, the 4/83 and 4/84 are totally different main boards. Both are commonly referred to as "4". There is a technical document on bitsavers, "Kaypro Technical Manual 1484F", which shows the official part numbers used in various models.

I've run into this. I've got a Kaypro 2X, 4/84, and 10 that all have the same motherboard and all have the RTC, populated HD interface, and modem. Everything I've read said the 2X was the same as the 4/84 except for the modem, but I've also read in a couple of different places that Kaypro would use what they had in stock for the later systems so sometimes you'd get lucky and get a fully populated motherboard. I guess I got lucky on my 2X and 4/84 or someone swapped the motherboards at some point.

I've also got a 10 that has an older motherboard with the HD connector in the center and it doesn't have modem (I can't remember whether it has the RTC).
 
Tezzas' Kaypro 4 is like my other unit with a modem (you can see the transformer on the board pic and the RJ-11 jack on the back as well as where the RTC battery should be, he has two wires running to another power source I am guessing) so his SHOULD have graphics.

This is right. I replaced the soldered in battery with a battery pack, which I've velcroed to the inside of the case. I DO NOT LIKE soldered in batteries, especially when the unit may several years before an internal check. I've seen too many wrecked mainboards.
 
I've run into this. I've got a Kaypro 2X, 4/84, and 10 that all have the same motherboard and all have the RTC, populated HD interface, and modem. Everything I've read said the 2X was the same as the 4/84 except for the modem, but I've also read in a couple of different places that Kaypro would use what they had in stock for the later systems so sometimes you'd get lucky and get a fully populated motherboard. I guess I got lucky on my 2X and 4/84 or someone swapped the motherboards at some point.

I've also got a 10 that has an older motherboard with the HD connector in the center and it doesn't have modem (I can't remember whether it has the RTC).

Yeah, I have a 2X (no chips - i.e. empty sockets - for modem, RTC, or HD interface) which I later had to replace the main board in. The new main board was essentially the same but fully populated (and with the "universal ROM"). But my 2X case says "2" with paper stickers adding the "X". The case could not have been for the original II since the I/O ports are the newer arrangement. I get the impression there was a lot of hodge-podge out of manufacturing. Not to mention what people might have done later to keep things running. But cutting new holes for I/O ports in that steel case would have been a pain. It's hard to imaging anyone going to that much trouble.

That technical manual I mentioned has been very interesting, revealing lots about different models.
 
Regarding the video/graphics issue:

The question of text mode vs. graphic mode for aliens.com and clone.com is actually in the blurry area between what is text and what is graphics. I used to work with both a Kaypro II and the later Kaypro 2 and saw this same problem. The Kaypro II would show the "screwed up" display and the '2 would display fine. Fiddling with the game a little on the older computer, I found that it was playing properly. I could still shoot and move, but the display was wrong and also seemd to need a wider screen.

Eventually I realized that the Kaypro II had the original character set and the '2 had the "newer" extended graphics character set: all high-bit characters (characters numbers 128 - 255) are various arrangements of the 2x4 large-pixel graphics that durgadas311mentioned in post 13. These are the bit-mapped characters Tezza mentioned in post #8. What the games do to create the graphics isn't done using the graphics mode, but instead they print the correct high-bit characters to produce the right "graphic image" in text mode. Watching Tezza's video carefully, you'll see that the alien crafts move more than 1 pixel at a time. They are actually moving 1 character at a time. (This technique was used often in many large-pixel graphic computers back in their hayday.)

But, not all of the possible arrangements have a character, only half of them do. You would need a total of 256 characters for all the possible combinations, and there are only 128 available. This was worked around by using the reverse video mode to invert the 2x4 pattern any time you needed one that wasn't in the character set. Again, as durgadas311 guessed, the non-graphic Kaypro II, can't interpret the <ESC> sequence properly and ends up placing additional characters on the screen that "stretch out" the spaceships, etc. on the display.

And there are 2 versions of this game: 1 ASCII only, 1 bit-mapped graphics. I was startled by this the first time I ran the ASCII version on the '2. Not knowing it was a different version, I was puzzled as to why the graphics suddenly stopped working. But when I ran the other copy I had, the graphics returned.

My best guess is that every Kaypro came with a version of the game and the pre-graphics Kaypros came with the ASCII version. Durgadas31's having one for the H89 sounds to me like this is the most likely case.
 
Back
Top