HP portable / HP 110 Service Manual

[J-F Garnier]

(08-19-2019 10:51 AM)S0N1C Wrote:  It seems Lotus came in 2 x 32KB 28 pin ROM chips

Oh, this is for the 110 (not 110 Plus), and Lotus was actually in more than 2 x 32k ROM (U52,53 plus parts of U56-59).
In the 110 Plus, Lotus was in a single pair of plug-in ROM chips in the ROM drawer.

So I assume your machine is a 110 (not Plus)? Then, yes, you should be able to replace a ROM with a 27C256. Now, you have to find an image of the ROM...

J-F