Functionally the LNW 80 model 1 ROMs are identical to the TRS80 ones. Some minor differences exist, probably for copyright reasons.

A long time ago Amardeep S Chana analized the two ROM sets I had and compared them with the Tandy Level II ROM:

I have analysed both images you sent and have identified all of the differences between Radio Shack Level II BASIC 1.0 and LNW-80 Level II BASIC (both versions). Here they are:

1. Sign on message differs, of course

2. "XOR A" instruction used in TRS-80 BASIC and "SUB A" instruction used in LNW-80 (both versions) at address 0001h. Both methods clear the A register to zero.

3. "OR A" instruction used in TRS-80 BASIC and "AND A" instruction used in LNW-80 (both versions) at address 0004Ch. Both methods update the flags register without affecting A register.

4. TRS-80 BASIC and the first copy of LNW-80 BASIC have the BASIC keyword "NAME" defined at address 16FDh-1700h. Second copy of LNW-80 BASIC replaces that with keyword "HRES".

Note that the high bit on the first letter of each word is '1' so you have to filter address 16FDh with "AND 7Fh" to convert the first letter to ASCII.

Those were all the differences I found. Very interesting that #2 and #3 are functionally equivalent. This may be done just to avoid copyright issues. #4 was probably to support high resolution graphics in some LNW-80 specific version of Disk BASIC.

Note: Another original difference between the two LNW ROM sets was that one contained no sign on message at all. As soon as I had an Eprom Programmer and a version with 'proper sign on' available I replaced the relevant EPROM. Apparently I didn't keep the original EPROM (this was 1986/1987).


Last update: 2023-01-12