Few years ago the zx81.de team shared interesting details related to the Lambda clones.
The well known color models had an earlier ROM version, probably too similar to the ZX81 one and missing the INK/BORDER/PAPER statements.
Moreover another variant used in the CAC-3 and the NF300 included support for the DATA/READ/RESTORE instructions, those two ROMs are not identical each other but very close.
I finally sorted out this mess by adding two new subtypes for the LAMBDA target (4, actually):
- mono/monofast for the older ROM lacking the color related code
- cac3/cac3fast for the NF300 and the CAC-3 models
I haven't completed the whole library port, yet, but almost all the examples should work already.
EDIT:
I must mention that Olofsen pioneered it and that some z88dk game was already tested on the monochrome ROM. Unfortunately we left this topic pending for about 5 years, probably because of the delicate code we needed to modify and test: if you owe a real Lambda clone of any tipe, please show up !!
ZX81 clones
ZX81 clones
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Re: ZX81 clones
The new modes:
-subtype=mono is the one for the less common v1 ROM, which was closer to the ZX81 one asked lacked colour instructions. The optional mlambdav1.lib and mlambdav1_tiny.lib maths optimisations are the valid replacements equivalenti to m81 or mlambda.
-subtype=cac3. Is for a less common variant, including the CAC-3 / NF300 models. Special Maths optimisation is not ready yet, use the generic libraries.
EDIT: for unknown reasons the CAC-3 library partially fails when used on the NF300 to exchange numeric values with BASIC (variables or C subroutines using the specific macros). It's a minor issue, but it is worth to mention.
-subtype=mono is the one for the less common v1 ROM, which was closer to the ZX81 one asked lacked colour instructions. The optional mlambdav1.lib and mlambdav1_tiny.lib maths optimisations are the valid replacements equivalenti to m81 or mlambda.
-subtype=cac3. Is for a less common variant, including the CAC-3 / NF300 models. Special Maths optimisation is not ready yet, use the generic libraries.
EDIT: for unknown reasons the CAC-3 library partially fails when used on the NF300 to exchange numeric values with BASIC (variables or C subroutines using the specific macros). It's a minor issue, but it is worth to mention.