mloewen
Experienced Member
In an old thread (https://www.vcfed.org/forum/forum/ge...0-rom-question), I talked about some problems I had trying to get a Kayplus ROM working in an older Kaypro 10 ('83). I finally got back into the system.
The Kaypro 10 had the 81-180 mainboard and the 81-302-C ROM. I installed the Kayplus 1.2 ROM (84), using a 28-pin socket adapter per their manual. The system would boot from a diskette generated by KPCNFG84 utility, but would not see the hard drive. HDCNFG would hang after displaying the banner. Based on some posts in other forums, it seems that the Kayplus ROM would not work correctly if the interface board (between the mainboard and hard drive controller) had been modified for the 81-302 ROM. I undid the modifications on the interface board, and it works! Specifically:
Removed the wire between U1 pin 3 and J2 pin 39.
Removed the wire between U1 pin 1 to J1 pin 45.
Bridged the cut between U1 pin 7 and U1 pin 2.
Bridged the cut between J1 pin 45 and J2 pin 39.
I have a Seagate ST-251 installed and configured as six 7MB partitions, with software reloaded from a CP/M 2.2G disk set. I also added the suggested modification for clock interrupts (U23 pin 27 to pad E8 on the mainboard), so the real-time clock works. I also ran the FIX22F program, even though I had booted 2.2G. The manual says that it installs a new CCP based on ZCPR. It seems to work okay, and the default drive search (User 0 on A: ) makes it worthwhile.
With the hardware changes to the interface board, the original 81-302-C ROM should not work, but I see no reason to go back to it. I hope this info will save some frustration for others attempting the same.
The Kaypro 10 had the 81-180 mainboard and the 81-302-C ROM. I installed the Kayplus 1.2 ROM (84), using a 28-pin socket adapter per their manual. The system would boot from a diskette generated by KPCNFG84 utility, but would not see the hard drive. HDCNFG would hang after displaying the banner. Based on some posts in other forums, it seems that the Kayplus ROM would not work correctly if the interface board (between the mainboard and hard drive controller) had been modified for the 81-302 ROM. I undid the modifications on the interface board, and it works! Specifically:
Removed the wire between U1 pin 3 and J2 pin 39.
Removed the wire between U1 pin 1 to J1 pin 45.
Bridged the cut between U1 pin 7 and U1 pin 2.
Bridged the cut between J1 pin 45 and J2 pin 39.
I have a Seagate ST-251 installed and configured as six 7MB partitions, with software reloaded from a CP/M 2.2G disk set. I also added the suggested modification for clock interrupts (U23 pin 27 to pad E8 on the mainboard), so the real-time clock works. I also ran the FIX22F program, even though I had booted 2.2G. The manual says that it installs a new CCP based on ZCPR. It seems to work okay, and the default drive search (User 0 on A: ) makes it worthwhile.
With the hardware changes to the interface board, the original 81-302-C ROM should not work, but I see no reason to go back to it. I hope this info will save some frustration for others attempting the same.