Omnibook 300 ROM compatibility

[kahlil88]

Looking to upgrade my OB-300 and wondering if the ROM cards for 425/430 are compatible? If not, maybe I can send someone my ROM card for modification. They appear to be technically identical aside from the 425/430 using a better CPU.

 

[maestro]

Sorry about the lateness. This thread is a bit old but maybe the answer will help someone. These omnibooks are some of the best ever made for DOS programmers.

Yes, they are compatible. Modifying a 300 ROM card would be difficult and more effort than it's worth. The units are technically identical aside from the ROM and CPU, which one's better is a matter of debate. The 486 is 5 MHz faster and adds 1 KB cache but uses more power, so it depends on the use case. The major benefit of the 425/430 card on the OB300 is larger disk support. If using the 425 ROM card, take a look at maximizing conventional memory under DOS. It's the best it gets with that particular ROM.

http://omnibooks.info/archive/ob300-530/FAQs/bpi01072.htm

 

[cshaxu]

I've tested different ROMs with different machines and it's very interesting.

Generally, the newer ROMs will work well with older machines but not the other way around.
For example, my 1.0 ROM card is not fully compatible with my OB 430, while the 1.1 ROM (for 425) and the 2.0 ROM (for 430) works great for my OB 300.