That System Software ADE was much later (and very good!), but I was talking about the predecessor of MASM, running on the System 3, which also happened to be called ADE (and I think there was an intermediate version called uADE).There was a commercial disc-based assembler called ADE from System Software but this used the syntax in which the addressing mode is given by the operand. But perhaps, by ADE, you mean Acorn's assembler development environment sold for the second processor. From what I have seen, this is EDIT (the same one from Pascal, though as a high version) with MASM.
This appears to have been sold as a product: there's a manual circulating online dated 1980 which presents itself as an Acorn product, but I don't know where it came from.
Possibly an attraction of the alphabetic-style address modes is making the source easier to parse? That ADE manual talks about loading it off cassette and needing a minimum of 4K RAM, so size was certainly of the essence at that point.
Anyhow, both sets of mnemonics were in use at Acorn from very early on - certainly by the time of the Atom you have the machine itself containing the BASIC assembler with one style of mnemonics, while system code for the Atom was assembled with the other style (I can't actually say for sure which assembler was used to assemble the Atom Basic itself, but the Atom Econet and the System/Atom DOS were definitely built using ADE/uADE).
Your theory that Microsoft popularised the one style, with the chip manufacturers suggesting the other in their datasheets, seems extremely plausible, but I think there's sufficient gap in time between Microsoft doing that and Acorn coming into existence that both were already established.
Personally, while I've probably written more code in the punctuation style, I find one advantage of the alphabetic style is that it's easier to pronounce it when talking to someone (or even when talking to yourself!):
L-D-A-I-Y foo
as opposed to
L-D-A bracket foo comma Y
or even
L-D-A indirect offset Y
So I'll often say "LDAIY" in my head and then type LDA (xxx),Y
Statistics: Posted by arg — Thu Jun 05, 2025 12:37 am